| namegoeshere |
I am interested in buyng a second vehicle for driving in a snowy region of the Fingerlakes region of New York State. My major concern is the ability to drive up my steep driveway during the winter when it's often covered with snow and ice. When I first moved here, I lost a transmission to my Plymouth van from my attempts.
I was thinking of either getting a Subaru (a very popular car here among the locals) and a Honda Element. I presently have an 03 X with VTM and during this past winter, there were days when I couldn't get up my driveway because of either ice or snow. Since the Element has the same VTM, and would presumably have the same snow performance as my MDX, would it be better if I buy a Subaru? I hate Subarus in general but the practical side overcomes in the long run. Does anyone have both vehicles who can help me out? Thanks in advance. |
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| DaleB |
quote:
Originally posted by namegoeshere
I am interested in buyng a second vehicle for driving in a snowy region of the Fingerlakes region of New York State. My major concern is the ability to drive up my steep driveway during the winter when it's often covered with snow and ice. When I first moved here, I lost a transmission to my Plymouth van from my attempts.
I was thinking of either getting a Subaru (a very popular car here among the locals) and a Honda Element. I presently have an 03 X with VTM and during this past winter, there were days when I couldn't get up my driveway because of either ice or snow. Since the Element has the same VTM, and would presumably have the same snow performance as my MDX, would it be better if I buy a Subaru? I hate Subarus in general but the practical side overcomes in the long run. Does anyone have both vehicles who can help me out? Thanks in advance.
Interesting stuff. Subarus and MDXs (and Elements I guess) are all about good traction on less than desireable roads and pathways. All 3 should do fine on your driveway.
4X4s are all about traversing rough terrain with little or no roads to speak of. |
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| KenF |
what about a good set of snow tires instead? A FWD car with the right tires will drive circles around a AWD with summer tires on it. Even the OEM MDX tires are 4 season, not true snow tires. They are for limited use in bad weather, not for a place with lots of ice and snow.
Plus it's a lot cheaper to get a second set of tires on some steel wheels than getting a second vehicle. |
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| wmquan |
If you are not able to get up your driveway with the VTM-4 "Lock" mode engaged (pushing the button), then I agree that you should look into better tires for such conditions.
Engaging the "Lock" mode of VTM-4 forces power to the rear wheels, up to 50% at low speeds when in 1st, 2nd, or reverse gears, with less percentage as you approach 18mph. This isn't the same as disengaging VSA, of course.
Forgive me if you already know this, but I have to ask. When you try to go up your icy/snowy driveway, and have trouble, do you try the "lock" mode (go to 1st/2nd/reverse gear, push the button, stay at low speeds)?
If you haven't, then it's worth trying. If you have, then you probably need snow tires for the winter.
A Honda Element does not have VTM-4. It has what Honda markets as "Realtime 4-wheel Drive." The primary difference is that it does not let you directly control sending power to the rears, sending it when slippage is detected and reacted to. Thus its AWD system would, all other things being equal, actually perform worse for you in some situations. Of course, things aren't equal, such as vehicle weight, tires, etc.
Subaru has at least three (four?) different types of AWD systems. Some are reactive like the Element system, some have some attributes of VTM-4 like sending power to the rear (or front) with certain acceleration parameters. The system on their manual-transmission models has a default split of 50/50 and is thus probably better for such conditions.
Thus, other things being equal, it depends on which Sube you buy. Again, other things aren't equal, as the Subes will have different tires, weights, etc. all of which will have an effect on your climbing ability. |
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| DaleB |
quote:
Originally posted by KenF
what about a good set of snow tires instead? A FWD car with the right tires will drive circles around a AWD with summer tires on it. Even the OEM MDX tires are 4 season, not true snow tires. They are for limited use in bad weather, not for a place with lots of ice and snow.
Plus it's a lot cheaper to get a second set of tires on some steel wheels than getting a second vehicle.
Having driven the MDX on icy, chains only, roads with stock Mich., and having driven all kinds of roads in the past with FWD: I will take the MDX anyday. |
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| The X-men |
| There isn't too many snowy driveways the VTM cannot handle, especially in the VTM lock mode. If the VTM cannot handle it, then you need a better set of tires or a 4WD system instead of AWD. A Subaru will not make much difference since it is just another type of AWD vehicle with lower ground clearance. |
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| XStatic |
quote:
Originally posted by KenF
what about a good set of snow tires instead? A FWD car with the right tires will drive circles around a AWD with summer tires on it. Even the OEM MDX tires are 4 season, not true snow tires. They are for limited use in bad weather, not for a place with lots of ice and snow.
Plus it's a lot cheaper to get a second set of tires on some steel wheels than getting a second vehicle.
Having driven a FWD vehicle with snow studded tires and a 1998 Volvo V70 AWD with speed rated low profile all weather tires I can say my experience does not match your assertion.
I haven't managed to get the MDX in the snow yet but I have experience a little slip in the rain. Not bad, just in a start from a complete stop.
The Volvo AWD on the other hand was fantastic, I never slipped while driving, even in complete icy conditions. At a 2 way stop intersection once after I came to a stop I started sliding sideways because of the way the road was angled for drainage. I put the vehicle in reverse to back away from the slope while I waited for traffic. When I got home and tried to wal across the street to get my mail I could hardly walk it was so icy. I had no idea the roads were that bad because the vehicle just stuck to the road even with those all season tires.
My FWD car with dedicated studded snow tires would often slip, not bad, it was basically controllable, but it certainly was not as good as the Volvo AWD.
After the Volvo, I don't think I will ever buy a 2WD vehicle again. |
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| renov8r |
In the Volvo the TRACS literally applies ABS to the wheel that spins faster than the driver knows. Thus on a road surface that is icy you wouldn't know that you've "lost" traction becuase the TRACS/ABS keeps you moving ahead.
In systems WITHOUT such electronic assist you would at least hear/feel the tire spin.
We also have to assume that by "icy roads" we are talking abouts roads that still have some patches that are not ice covered -- otherwise you could ONLY drive if you had studs that cut through/into the ice ...
quote:
Originally posted by XStatic
Having driven a FWD vehicle with snow studded tires and a 1998 Volvo V70 AWD with speed rated low profile all weather tires I can say my experience does not match your assertion.
I haven't managed to get the MDX in the snow yet but I have experience a little slip in the rain. Not bad, just in a start from a complete stop.
The Volvo AWD on the other hand was fantastic, I never slipped while driving, even in complete icy conditions. At a 2 way stop intersection once after I came to a stop I started sliding sideways because of the way the road was angled for drainage. I put the vehicle in reverse to back away from the slope while I waited for traffic. When I got home and tried to wal across the street to get my mail I could hardly walk it was so icy. I had no idea the roads were that bad because the vehicle just stuck to the road even with those all season tires.
My FWD car with dedicated studded snow tires would often slip, not bad, it was basically controllable, but it certainly was not as good as the Volvo AWD.
After the Volvo, I don't think I will ever buy a 2WD vehicle again.
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| XStatic |
quote:
Originally posted by renov8r
We also have to assume that by "icy roads" we are talking abouts roads that still have some patches that are not ice covered -- otherwise you could ONLY drive if you had studs that cut through/into the ice ...
The icy road was caused by snow, followed by freezing rain. No asphalt was visible, no salt or scraping was done, and even though I am a pretty good ice skater and even used to "ski" down large hills during high school in my slick soled marching band shoes, I had a very difficult time just walking across the street to get the mail.
While not as smooth as an ice rink, it was mostly rock hard solid ice. |
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| namegoeshere |
Thanks for everyone's comments but there doesn't seem to be much of a concensus other than it depends on the car. With respect to some of the queries. I lost my van transmission which I had 4 Michelin Artic Alpen tires so I did have winter tires and even that didn't get me up the driveway.
On my MDX (wmquan's query) I did certainly try the "lock" feature. I was able to make it up three quarters of the way and even though I can sense all four wheels turning, the X was not making foward progress and the wheels were spinning on the snow on top the ice underneath. The X was starting to move sideways which is a really scarey as there are gullies on either side. What's more freightful is sliding and driving backwards down the driveway knowing that you have no traction if you put on the brakes. I'm just glad there are no cars on the road else I won't be able to stop.
Any more advice? In wmquan's reply, does that mean that the Elements system is the same at the VTM-4 except that you can't lock it up like we can in the X? |
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| XStatic |
RealTime Looks a lot like VTM-4 as they both operate in FWD mode with the driveshaft always in motion. However Realtime operates mechanically while VTM operates electronically and thus can respond quicker, with other sources of input such as accelerator position, and can lock the differential.
Transmission: RealTime™ 4WD system
The RealTime™ 4WD system on the CR-V is designed to overcome the traditional drawbacks of a full-time four-wheel drive system - notably lower fuel economy, higher noise and vibration levels, higher weight and difficulty in adapting the system to ABS. The CR-V's RealTime™ 4WD operates automatically and only when needed. It requires absolutely no intervention on behalf of the driver for it to be engaged or disengaged.
The CR-V's RealTime™ 4WD system sends power only to the rear wheels when there is insufficient traction for the front-wheel drive system. The system consists of the conventional front-wheel drive system - a compact transfer system that distributes drive to a propeller shaft running the length of the vehicle, a dual-pump system, the rear differential, and left and right rearwheel driveshafts.
The heart of the system is the dual-pump unit. It consists of two hydraulic pumps - one driven by the front wheels via the propeller shaft and one driven by the rear wheels via the rear differential.
A hydraulically actuated, multi-plate clutch - similar to the clutches used in Honda automatic transmissions - connects the propeller shaft to the rear differential.
When the CR-V is operating with the front and rear wheels turning at the same speed - for example, on dry bitumen - the front and rear hydraulic pumps operate at the same speed.
Hydraulic fluid circulates between the two pumps; however, no pressure is generated. In effect, the fluid fed by the front pump is absorbed by the rear pump.
If the front wheels begin to turn faster than the rear wheels - as would be the case if they were spinning on snow or ice - the two hydraulic pumps would turn at a different rate and hydraulic pressure proportional to the difference in their speeds of rotation would be generated. The resulting hydraulic pressure opens a valve body and feeds pressure to the multi-plate clutch, which engages the front propeller shaft to the rear differential. The rear differential feeds the
drive torque to the right and left rear wheels.
System operation is completely automatic - no electronics or driver action is involved. The greater the degree of front-wheel slippage, the greater the amount of torque fed to the rear wheels. RealTime™ 4WD is also practically maintenance- free, requiring only a scheduled fluid change at 120,000 km and every 60,000 km thereafter. Another big advantage of the CR-V's dual-pump RealTime™ 4WD system is that, unlike conventional 4WD systems, RealTime™ 4WD automatically disengages under braking, thereby allowing the ABS system to engage.
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| KenF |
quote:
Originally posted by namegoeshere
Thanks for everyone's comments but there doesn't seem to be much of a concensus other than it depends on the car. With respect to some of the queries. I lost my van transmission which I had 4 Michelin Artic Alpen tires so I did have winter tires and even that didn't get me up the driveway.
Sounds more like it's your driveway! Do you have friends with other vehicles that drive it when it's icy? If it's completely iced over there probably isn't much that's going to make it up the hill without a running start. Getting traction on pure ice is difficult for any kind of transmission. |
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| wmquan |
quote:
Originally posted by namegoeshere
... On my MDX (wmquan's query) I did certainly try the "lock" feature. I was able to make it up three quarters of the way and even though I can sense all four wheels turning, the X was not making foward progress and the wheels were spinning on the snow on top the ice underneath. The X was starting to move sideways which is a really scarey as there are gullies on either side. What's more freightful is sliding and driving backwards down the driveway knowing that you have no traction if you put on the brakes. I'm just glad there are no cars on the road else I won't be able to stop.
Any more advice? In wmquan's reply, does that mean that the Elements system is the same at the VTM-4 except that you can't lock it up like we can in the X?
Yes, the Element's system is a subset of the MDX's and it will probably perform worse, other things being equal (the Element is lighter and has different tires, of course). Besides not having a VTM-4 Lock mode, I don't think it manages side-to-side traction. E.g. if the right front wheel is spinning with no traction, power bleeds out on an open differential, and the left wheel doesn't get enough torque even though it may have tire grip. Same with the rear wheels, side-to-side. CR-V/Element fans, please correct me if I'm wrong.
On the MDX, VTM-4 is supposed to vary the torque between the two rear wheels based on slippage, and VSA is supposed to apply sufficient pulse-braking on a front wheel to let torque get to other front wheel with traction.
So in regard to your issues, there are two possibilities since you are using the lock mode (in 1st/2nd/reverse gears, doesn't work beyond, of course):
1) Try winter tires. Even though your other vehicle had winter tires, its drive system wasn't the same as the MDX, so having snow tires plus VTM-4 may just be enough to do the trick.
2) VTM-4 handles most situations but doesn't handle 100.00% of them. E.g. VTM-4 and VSA have some delays in reaction time and the amount of torque it can send to any particular wheel is limited. When you start slipping to the side, it's because you can't get enough grip, and/or whatever tire has potential grip isn't getting enough power quickly enough to balance everything off.
It is thus conceivable that a different 4WD system may do the trick. I'm thinking about the system on the Toyota 4runner (Torsen-based, with some locking ability). Or the ML or X5's systems which are more traction-control based systems. But I don't think the Subaru will resolve it.
But I'd try the snow tires first. |
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| y2ks2k |
Well, I think I can get a good opinion in on this one lol.
When it snowed here, I did not drive my Sti, I drove my MDX. It was pretty nasty for this area (once a 10 year thing). It drove perfectly, I could navagate anything. I was behind "4wd beasts" that were slidding all over the road in front of me and had no problems. I could see driving an Outback and such in it but not my Sti. So in snow, the MDX wins. As far as AWD goes in general, the mdx is weak and not a very good system when it comes down to it at all. The Subaru system (especially in the Sti) is amazing at best (but then again, it has a limited slip in the front, rear and the dccd). If Acura put this VTM system on say the TL to call it an "AWD" car, it would be laughed at in the performance circles (note, I used to own a TL Type S). there is nothing like have in a true rear wheel biased AWD system on full time. Not only that but it is like a ROCK and is unbreakable. |
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| roadman |
quote:
Originally posted by KenF
what about a good set of snow tires instead? A FWD car with the right tires will drive circles around a AWD with summer tires on it. Even the OEM MDX tires are 4 season, not true snow tires. They are for limited use in bad weather, not for a place with lots of ice and snow.
Plus it's a lot cheaper to get a second set of tires on some steel wheels than getting a second vehicle.
A vehicle that transfers power to different wheels will always be safer to drive than one that limits it's power delivery to one wheel.
I have a TL-S and snow tires make no difference on it's spin happy tendencies. Having so much torque along with an Auto makes it very poor in the snow. Had it had a manual trans it would be much more controllable. So a manual trans is also much more desirable in the bad weather.
A set of snow tires will help most cars, but remember that all 4 tires will need to match or safety will be compromised in all driving conditions. |
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| Dick at Incline |
The VTM-4 SYSTEM is an automatic all-wheel-drive system that kicks in the rear wheels (different amounts of power to each rear wheel) whenever they are needed for traction; the driver needs to do nothing to initiate this action. Normally the MDX operates in FrontWD, however the VTM-4 applies some power to the rear wheels every time you accelerate, no matter what the speed, and is VERY capable in snow.
The VTM-4 LOCK button is a "lock-the-system-on-no-matter-what" device, and shouldn't be used for any other purpose than getting unstuck (or getting up and down steep driveways!) With all the power and the lock on, traction will depend on your tires, or even putting chains on if you have them.
VTM-4 is always on. It has three methods of engagement, with engagement being defined as sending power to the rear wheels (which normally get zero power).
1) When slippage in the front wheels is detected. Power is sent to the rear based on some mysterious algorithm (up to about 50%), and it can vary between the left rear wheel and the right rear wheel. There is no visual indication that this engagement has occurred, other than the Yellow Triangle with the “!” may flash.
2) Under some acceleration scenarios. Power is sent to the rear; Acura doesn't publish what the algorithm is, however. I'm not sure if each rear wheel can get a varying amount of power in this circumstance. There is no visual indication that this engagement has occurred, other than the “!” which may flash.
3) When the VTM-4 Lock button is pressed. Pressing this button does not engage VTM-4, which is already engaged. Rather, it engages "VTM-4 Lock Mode." In this scenario, the algorithm will send power to the rear only when the vehicle is in Reverse, 1st, or 2nd gears and traveling up to 18 mph. The four wheels are locked in 4WD with equal power being sent to Front and Rear Wheels, until 6MPH. As the vehicle goes faster, less and less power is sent to the rear until 18MPH when it goes back to normal VTM-4 AWD operation. Additionally, at less than 18MPH the two rear wheels are locked so they do not spin independently.
The fact that the two rear wheels are locked is a key. If you attempt to turn, it causes significant friction and heat. This is one reason the algorithm disengages the lock above 18mph -- you'd probably burn out the rear clutch packs if you tried turning at faster speeds. This is the other reason why VTM-4 Lock should only be used when you are trying to extricate yourself, and not for very long periods of time, and not with much turning.
One thing that most of us who are used to driving in Snow, use and understand, is Momentum. You can make it through slippery and slightly icy areas if you just--keep 'er movin'. This does not have to be fast--5 mph or so is enough. But if you get stopped on even a slight grade, and it’s a little icy, it may be impossible to get started again even with “VTM-4 Lock”, but a little momentum can get you through.
I really like Cables because they meet the chain requirements, are easy to install, fit tight, are cheaper (~$30.) and are more compact to carry than chains. I carry mine in the under-floor compartment in rear. (Of course, if you need them, you install them on the fronts.)
Here’s a great Video on VTM-4: http://acura.com/images/media/abo_end_vtm.mov |
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| namegoeshere |
Wow, great explanation. I didn't know about the both wheel locking feature of VTM-4.
Yesterday, we got 8 inches of fresh snow and I took off early in the afternoon to test drive an 02 Subaru Outback and an 04 Honda Element. My driveway was complelely covered except for two slight tread marks from when I took my X out in the morning. My wife and I first took the Subaru to my driveway. I was able to get it up my driveway with a constant speed without much of a running start other than a right turn from the street to my driveway. I let me wife try next. She was only able to get up 3/4 of the way until all four tires started spinning (I know all 4 tires were spinning because I was outside intentionally to see how which wheels are spinning if it slips). The car started moving sideways and before it could go off, my wife put it in park with parking brakes, got out and said that's it, no Subaru! The snow in front of the front tires appear to halt it's progress.
With the Element, we were both able to get it up our driveway, my wife once and me twice. So whatever the theory, I guess the Element is the car for us. I know this is not a perfect experiment as I'm sure the Element's tire is in better shape (Element had 9 miles while the Subaru had 30K). Also, looking at the tire spin, I think my wife gased it midway up the driveway with the Subaru and started the tire spinning and therefore losing traction. This has to do with her driving but that's another battle..... |
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| perk |
I would go with the Element in any event. I test drove one for more than an hour last weekend. Thinking of unloading the X because now that I've moved to DC, I rarely drive it. Too expensive to just let sit in the garage.
Anyway the Element is awesome and unbelieveably priced at only $21k for a loaded AWD. It's quiet, powerful, smooth, and solidly built. But most of all, that purposeful plastic interior is great. Would be great for someone who needed to haul yard equipment, plants, etc. in the back. Also looks great for trips since it averages 25mpg (according to Car & Driver long-term test) and converts easily to a bed in back. The only complaint I have is that the rear opening is only 44" wide. I'm not sure I can have a car that can't haul plywood and sheetrock when needed. Pretty sure the Element can haul these things, but just not lying flat. If I can convince myself that its ok to haul that stuff diagonally, I'll probably go ahead and sell the X then buy an Element. We'll see.
But, in your case, definately buy the Element and please keep me up to date on how it goes. |
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| DaleB |
quote:
Originally posted by namegoeshere
I know this is not a perfect experiment as I'm sure the Element's tire is in better shape (Element had 9 miles while the Subaru had 30K).
Actually tires gain more even traction across the tread (given no alignment problems) when they have some noticeable wear than when new. Less squish too. This is especially true in dry handling.
But reducing the depth of the grooves, might certainly impair 'snowability' to a degree. |
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| Dick at Incline |
quote:
Originally posted by namegoeshere
I let me wife try next. She was only able to get up 3/4 of the way until all four tires started spinning (I know all 4 tires were spinning because I was outside intentionally to see how which wheels are spinning if it slips).
It seems to me that if all 4 wheels are spinning--that is, that all 4 are trying to drive, then that's as good as it gets. Then it all gets down to traction, which is primarily the TIRES. Better tires with more agressive tread, that is bigger gaps in the tread would probably make the difference. Older tires with less tread will have the tread fill with snow and then just slip and slide.
The reason you made it up and your wife didn't is probably technique--maintaining momentum, constant easy throttle, turn the steering wheel gently, etc.
So much is dependant on technique and tires, I wouldn't give up my very safe MDX (size and impact protection), for a Honda Element. You've already taken a big hit on depreciation--get a good set of snow tires and have them mounted on an extra set of Rims, and the MDX will do every bit as well as the others--It's all a matter of traction.
As a side comment, my '97 Jeep Cherokee which is a 4WD, will sit in the snow with one tire spinning, and the rest doing nothing. I'll take AWD anyday over that kind of 4WD. |
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| XStatic |
quote:
Originally posted by Dick at Incline
It seems to me that if all 4 wheels are spinning--that is, that all 4 are trying to drive, then that's as good as it gets. Then it all gets down to traction, which is primarily the TIRES.
It seems to me it could be better. Static friction is greater than dynamic so I would think ideally a system in full slip could cycle trough each tire with ABS to stop the wheel and then let it slowly spin up. By cycling through all 4 tires you are bound to get one to bite at some point...
This would be impossible to do without the computer since actually bringing the vehicle to a halt to get the wheels to stick again would cause you to loose momentum which just makes things worse.
This is just my personal theory and I have no idea if any vehicle does t. |
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| XStatic |
This is how the Volvo works, I can tell you from experience it is a rock solid performer. I never felt any wheel slip under any condition, unlike my experience in the MDX which I have felt front wheel slip in the rain. BUT the Volvo system has (or at least had)a weakness, the bevel gear, which is expensive to replace!
Engine power can be diverted to rear wheels through a transfer differential located adjacent to the transmission. Power can be split to either the front or rear wheels in varying amounts as road conditions dictate and without driver intervention. Further downstream in the drive line resides the main component that handles engine power transfer, the viscous clutch. In simple terms it is a type of turbine in which power that normally drives the front wheels is instantly transferred to the rear wheels to help maintain optimum vehicle traction. It is the key to Volvo's AWD system. The viscous clutch normally allows 95 percent of the engine power to remain directed to the front wheels and five percent to the rear wheels under conventional driving conditions.But as soon as a wheel slip is detected, the viscous clutch adjusts torque distribution to all wheels and when necessary, can transfer up to 95 percent of the engine power to the rear wheels. This all takes place in milliseconds--well before a driver would be capable of making such a decision. No special technical or driving skills are required to operate the all-wheel drive mode. The entire action is completely transparent to the driver. In fact, the action is similar to what occurs in an automatic transmission.
Volvo's transmission has been modified and extended to include a compact transfer differential. The power is transferred between the transmission's differential housing and bevel gear's tubular shaft via a splined joint. The bevelgear's wheel and pinion and the final drive have the same numerical ratio between the front and rear wheel.At the rear edge of the transfer differential there is a drive shaft which leads to the rear wheels. This shaft has CV joints at the front and rear and a U -joint in the center, where the intermediate bearing is situated. The drive shaft runs through the standard floor tunnel which permits the installation of the system with only a few minor modifications.
The viscous coupling, which is located ahead of the rear differential, appears as a long tube filled with silicone oil and contains a large number of discs. The viscous clutch is designed to use the silicon oil's viscosity to transfer power via the discs to the rear wheels when the front wheels start to spin. Every other disc is connected to the front wheel part of the shaft and the alternating discs are connected to the rear differential. When the discs revolve at a different rate the silicone oil in which the discs rotate becomes more viscous and thus increases the pressure. As this pressure increases, torque is transferred to the rear wheels. If the viscous coupling is subjected to intensive slipping, the silicone oil and discs become very hot. At this point, the coupling locks-up to prevent any slippage.
Volvo has also engineered into the drive line system a freewheel component.This unit disengages the rear drive during braking and/or coasting help ensure optimum braking performance. With this feature, the ABS braking system does not need modification. Another refinement, when it comes to this freewheel, is that it also has a lock-up function. This means that Volvo's AWD system is always in four-wheel driven when it reverses.
Volvo engineers have also incorporated a locking differential for the rear axle drive unit, and Traction Control System (TRACS) for the front drive unit to help ensure that the correct amount of power is distributed as needed at low speeds. The locking rear differential senses minute differences in rear wheels rotational speed and at speeds less than 25 mph automatically locks both rear wheels to transfer engine power to help maintain traction. TRACS, based on an ABS feed back system, is designed to work at speeds of less than 25 mph and is especially useful in helping to prevent front wheel spin at vehicle launch. Both these systems, locking rear differential and front wheel TRACS, working together help to prevent wheel spin, thereby helping to ensure maximum take-off traction control on most slippery road surfaces. |
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| Dick at Incline |
quote:
Originally posted by XStatic
That video shows the 2004!
Good Call, I hadn't noticed that. However, I don't believe they changed VTM-4 from the '03 to the '04 model. |
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| wmquan |
quote:
Originally posted by perk
Thanks for posting that. Good to know and it's something to consider. But I didn't feel so bad about that when I compared the Element to other cars as shown here.
Sure, the Element does fine in the front offset crash. But please consider that the CR-V has the same drive system, a better side impact score and also has optional side airbags. I doubt if those side airbags would have raised the score to a "Good" but there's a decent chance it would have been at least an "Acceptable." Certainly better than "poor."
NHTSA's side impact test is much lesser than IIHS's, the latter uses a larger barrier meant to at least partially simulate a larger SUV impacting on the side (NHTSA's is the size of a Corolla). But even NHTSA found issues with the Element's side-impact results, despite the lower barrier:
http://www.nhtsa.gov/NCAP/Cars/2004SUVs.html
The CR-V is more expensive, however. |
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| 04MDX |
| I own a 1999 Subrau Forester and a 2004 MDX. Both are great in the snow. I tried to get the Subrau stuck in 12' of snow a few years back and could not. The snow was up to the door!!! The MDX seems as sure footed as the Subaru... |
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| GDTRFB |
Thanks XStatic...I remember reading this with great interest when you originally posted it. It is among the best explanations I have seen on this subject. Can you please give me your opinion here? We are considering replacing a '98 Subaru Forester with a new Honda CR-V SE. (For my wife) My biggest hesitation and concern is that the CR-V will not be as good as the Subaru in the snow, which is an important consideration here in NY. Especially for her! Any additional comment or reassurances would be most welcome.
2004 MDX Touring w/Navigation
quote:
Originally posted by XStatic
RealTime Looks a lot like VTM-4 as they both operate in FWD mode with the driveshaft always in motion. However Realtime operates mechanically while VTM operates electronically and thus can respond quicker, with other sources of input such as accelerator position, and can lock the differential.
Transmission: RealTime? 4WD system
The RealTime? 4WD system on the CR-V is designed to overcome the traditional drawbacks of a full-time four-wheel drive system - notably lower fuel economy, higher noise and vibration levels, higher weight and difficulty in adapting the system to ABS. The CR-V's RealTime? 4WD operates automatically and only when needed. It requires absolutely no intervention on behalf of the driver for it to be engaged or disengaged.
The CR-V's RealTime? 4WD system sends power only to the rear wheels when there is insufficient traction for the front-wheel drive system. The system consists of the conventional front-wheel drive system - a compact transfer system that distributes drive to a propeller shaft running the length of the vehicle, a dual-pump system, the rear differential, and left and right rearwheel driveshafts.
The heart of the system is the dual-pump unit. It consists of two hydraulic pumps - one driven by the front wheels via the propeller shaft and one driven by the rear wheels via the rear differential.
A hydraulically actuated, multi-plate clutch - similar to the clutches used in Honda automatic transmissions - connects the propeller shaft to the rear differential.
When the CR-V is operating with the front and rear wheels turning at the same speed - for example, on dry bitumen - the front and rear hydraulic pumps operate at the same speed.
Hydraulic fluid circulates between the two pumps; however, no pressure is generated. In effect, the fluid fed by the front pump is absorbed by the rear pump.
If the front wheels begin to turn faster than the rear wheels - as would be the case if they were spinning on snow or ice - the two hydraulic pumps would turn at a different rate and hydraulic pressure proportional to the difference in their speeds of rotation would be generated. The resulting hydraulic pressure opens a valve body and feeds pressure to the multi-plate clutch, which engages the front propeller shaft to the rear differential. The rear differential feeds the
drive torque to the right and left rear wheels.
System operation is completely automatic - no electronics or driver action is involved. The greater the degree of front-wheel slippage, the greater the amount of torque fed to the rear wheels. RealTime? 4WD is also practically maintenance- free, requiring only a scheduled fluid change at 120,000 km and every 60,000 km thereafter. Another big advantage of the CR-V's dual-pump RealTime? 4WD system is that, unlike conventional 4WD systems, RealTime? 4WD automatically disengages under braking, thereby allowing the ABS system to engage.
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| namegoeshere |
| In case any of you are interested, I decided to buy the Toyota Matrix with AWD instead. Now I just have to wait for snowfall to see how Toyota's system handles my problem. |
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| XStatic |
quote:
Originally posted by GDTRFB
Thanks XStatic...I remember reading this with great interest when you originally posted it. It is among the best explanations I have seen on this subject. Can you please give me your opinion here? We are considering replacing a '98 Subaru Forester with a new Honda CR-V SE. (For my wife) My biggest hesitation and concern is that the CR-V will not be as good as the Subaru in the snow, which is an important consideration here in NY. Especially for her! Any additional comment or reassurances would be most welcome.
2004 MDX Touring w/Navigation
Sorry for the bad news but I have no basis for making a recommendation as to the relative performance of these two vehicles.
However, my guess is that overall the Subaru would outperform the Honda for a number of reasons:
1) More sophisticated AWD
2) More experience building/tuning AWD
3) Normalized for AWD, not 2WD (downside is loss of MPG)
4) Lower center of gravity |
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| jsavrtka |
quote:
Originally posted by 04MDX
I own a 1999 Subrau Forester and a 2004 MDX. Both are great in the snow. I tried to get the Subrau stuck in 12' of snow a few years back and could not. The snow was up to the door!!! The MDX seems as sure footed as the Subaru...
Yikes! Shades of Spinal Tap here!
My Subaru with manual gearbox has a 50/50 split between front and rear, which cannot be changed. It doesn't have LSD (although some models do). I still love it.
Before that, I had a front-wheel-drive. The winter tires made a huge difference, but I still think AWD has the advantage using just all-season tires. Putting winter tires on my Subaru didn't make a huge difference, because it had good traction already. It does help with braking and cornering though.
Our subie has changed the way we look at vehicles, which is why we are considering the MDX.
All Wheel Drive--All We'll Drive
jim |
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| eurohazard |
I don't know if the newer CR-V AWD system is any different than the 1st Generation. But my 1997 CR-V was a snow hound. It performed flawlessly in the snow. It also performed miracles in freezing rain/sleet.
Now the strange thing is, if I was on a steep incline in the rain, and I gunned the throttle, I could break traction in the front wheels for several seconds before the rear kicked in. This was actually a very fun maneuver, and I did this a lot just for the fun of it.
But driven like a normal person would drive, the CR-V was outstanding in the snow! One other tidbit.....a CR-V will NOT do dough nuts in the snow! The traction is that good. I tried as hard as I could, but the little Honda just kept on going in big controlled circles with no drama what so ever.
quote:
All Wheel Drive--All We'll Drive
very cute....I like that |
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| phlex |
excellent post dick! lots of helpful info. i just want to comment on ur last remark about if u need chains..on the front of course. true, if u need the extra traction for climbing, that makes sense. but in my case with pirelli scorpions i can climb the hill to my home (500' rise in 1 mile with most occurring in one 1000' section) just fine without chains. but coming down is another story! several people have gone off the edge by rotating. i put my chains on the rear so that when i brake it stabilizes the car (keeps it straight). i fear that with the chains on front there would be a tendency for the rear to want to come forward if I'm the least bit at an angle. having talked to 2 of the people that went over the side, they confirmed that this is what happened to them. icy conditions, braking lightly, keeping speed below 5mph when one of the front wheels gets on a clear spot and grabs it. they deduce that they must have been a slight angle and a rotational momentum was induced. one rotated 180 deg, the other 270 before going over the 80' drop at ~35 deg. both cars were totaled but fortunately no one was killed. i take the chains off at the bottom. if it was ever the case i couldn't climb this sucker, i'd put them on the front for the same reason i have them on the rear going down...stability!!
alive in boulder, CO
:) |
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