| goode9100 |
| Do any of you used 87 or 89 octane gas or only premium? |
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| EXCALIBUR |
goode9100,
I use 87 octane gas exclusively. |
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| G. COLTON |
I jump around depending upon my mood that day. If I am in a tightwad mood I buy 87, if I am in a spending mood I buy premium.
G |
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| Dr. Ken |
| Always premium. I know I probably don't need it, but it just seems to run better with the high test stuff. Besides, I am a stickler for following manufacturer's recommendations. |
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| phild_mason |
I run mid grade 89 or 90 octane in my MDX and RL. In the midwest there are lots of places that offer a ethanol blend midgrade for the same price or even less than regular.
This has been hashed here repeatedly, but I honestly think that the premium requirement is putting lipstick on the pig so to speak.
The Pilot, MDX and Honda minivan come off the same line. They use the same 3.5 engine. Two of those vehicles do not require premium, one does.....The way most of us drive it makes no difference. I have had good to better mileage with various grades so I have seen no relationship there. The only thing that really changes miles per gallon is speed and wind direction. |
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| antnecc |
We been using 87 octane now on my 2004 MDX that now has 46,000 miles and didn't notice a warranted difference in the time I did use 89 and 93. I did a month of each and I drive the same highway each day so it was an even match between all grades. Now the Pilot has the 3.5L engine and calls for 87 octane. I was told buy a service tech at Curry Acura that the difference between the two is horsepower, that I wouldn't really notice or worth the extra money.
So that is my 20 cents a gallon worth
Anthony |
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| penultimateonee |
| As directed by my Acura Service Manager, I run 87 Octane, and my previous low-RPM hesitation problem has all but disappeared. |
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| kunB |
whats the mpg you are getting when using 87 Octane fuel. Its been 3 months I have had my MDX, and have been using premium all these times to fill up and I get 18 mpg (mostly city driving).
Will the mpg decrease when I use a lower octane fuel ? |
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| MesaBeige |
quote:
Originally posted by kunB
whats the mpg you are getting when using 87 Octane fuel. Its been 3 months I have had my MDX, and have been using premium all these times to fill up and I get 18 mpg (mostly city driving).
Will the mpg decrease when I use a lower octane fuel ?
I've been using regular for about three years now. No problems. I do get just less than 1 mpg on average less than I was with the high octane. |
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| rvehock |
| With my driving habits I get the same MPG on regular as I do with premium fuel. I always average right at 17mpg in the city and between 22 and 25mpg on the freeway. My wifes 3.2 TL gets 19mpg city and between 28 and 32mpg on the freeway also running on regular fuel. I have decided that I will not go back to premium until it gets under $2 a gallon, looks like I will be using regular fuel for quite awhile :eek: :eek: :eek: |
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| penultimateonee |
With Premium or 87 Octane Fuel, I get an overall average of about 17MPG. On highway cruising @ 80MPH 21MPG, @ 65MPH 22.5MPG; in town about13MPG.
2001 Touring, w/ 85,000 Miles |
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| loa3 |
| We've used 87 octane since our 2004 was new and it operates fine. In city driving, the engine doesn't care what octane is being used when the vehicle is sitting at a traffic light or in stalled traffic. On the highway, we've driven in the mountains in the summer as well as flat land and have never had any knock. If the Pilot can use regular, the MDX can use it too. |
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| jimbo8 |
| I have had our 2006 MDX since Jan. and have been using premium fuel as advised by the dealer. I'm glad to hear that the MDX can run just as smooth on the 87 Oct. I 'm switch'n on my next fill-up !!:2: |
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| anjan |
quote:
Originally posted by loa3
We've used 87 octane since our 2004 was new and it operates fine. In city driving, the engine doesn't care what octane is being used when the vehicle is sitting at a traffic light or in stalled traffic. On the highway, we've driven in the mountains in the summer as well as flat land and have never had any knock. If the Pilot can use regular, the MDX can use it too.
This seems to be quite an educated post :D There never will be any knock - that's the whole idea behind the knock sensor - it detects lower grade fuel and retards the timing to prevent premature detonation. That is the reason for reduced hp and fuel economy. You could hear knocking in the 70s when they didn't have knock sensors.
Before anyone starts flaming - I'm talking about ANY engine that's designed to run on Premium Fuel - you can run it even on kerosene but economy and throughput suffer (per automotive engineering). |
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| Jey |
| I have always used 87, & it runs excellent! |
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| KES |
| Interesting- you spend $40K on a vehicle that the Honda engineers says needs 91 octane in order to get the maximum performance out of the engine. At 20 cents a gallon for 91 versus the 87 octane that comes to about $3 to $3.5 per tank or about $150 per year. I really don't think Honda has any motivation to recommend the higher octane other than the engine was designed to get the best performance with that octane. |
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| bayoun1 |
| This has to be the $64,000 dollar question for all new (high compression) car buyers... showing my age now! I'm concerned that 87 octane will foul the head and plugs with carbon as a result of improper firing... the higher octane is intended to avoid premature firing in higher compression engines (like the MDX)... the "knocking" that results from using too low of an octane is the worst indicator of the carbon fouling problem... Has anyone (who uses 87) had hesitation/engine vibration as a result of carbon deposit build-up?? |
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| chipero |
I just bought a used 2005 MDX and I 'm a cheap bastard so I was curious to find out If I have to use Premium gas or can I just use Regular gas?
Regular Gas is over $2.65/gal and Premium is over $3.05/gal here in S. Florida so it will make a hugh difference if I don't have to use premium. Look forward to all the users answers.... |
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| KES |
I think the best way is to run 5-10 tanks on 91 and then 5-10 tanks on 87 and determine the MPG averaged under both octane and then determine the cost differential. I have not done a scientific study but I have noticed slight poorer mileage when I have put a lower octane in the tank. I use 93 because 91 is not available at the local station. Those that use 87 will swear there is no decrease in mileage and performance and those using 91 will counter that position. Try both and make your own decision.
It is interesting in that the owners manual says that you can go 7500 miles between oil changes but nobody believes that and spends more $$ changing the oil at 3500 miles. Then we then disagree with the owners manual that recommends 91 for peak performance yet choose 87 because it is cheaper. |
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| kunB |
Yes. that is true. The dealer themselves will tell that dont follow factory recommendations for oil change. Follow their recommendation - which is 3500 miles. Pohanka are you listening ?
quote:
Originally posted by KES
I think the best way is to run 5-10 tanks on 91 and then 5-10 tanks on 87 and determine the MPG averaged under both octane and then determine the cost differential. I have not done a scientific study but I have noticed slight poorer mileage when I have put a lower octane in the tank. I use 93 because 91 is not available at the local station. Those that use 87 will swear there is no decrease in mileage and performance and those using 91 will counter that position. Try both and make your own decision.
It is interesting in that the owners manual says that you can go 7500 miles between oil changes but nobody believes that and spends more $$ changing the oil at 3500 miles. Then we then disagree with the owners manual that recommends 91 for peak performance yet choose 87 because it is cheaper.
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| phild_mason |
Of course dealers want you to use the lower 3500 miles. It makes them more $$'s and gives them more opps to up sell owners on other un-needed stuff like $15 bottles of injector cleaner.
Lubrication related failures are just about un-heard of anymore. Engines are built far better and lubricants are better. |
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| vetdude |
I cannot understand why the MDX owners manual calls for "Premium Fuel Only" when the Honda Pilot has the exact same engine and it calls for "Regular Fuel." DON'T WASTE YOUR MONEY!!! Here is an interesting read from the Corvette Forum related to octane:
Lots of gasoline comments lately. I’m an engineer for a major oil company, familiar with engine testing for performance, economy, and emissions. I think my company’s gasoline is slightly better than other majors, but I’m not going to use the forum for advertising. Instead, I’ll make a few points about what you should look for in a gasoline. If you do that, my company will get more than an average share of your business.
Octane is generally misunderstood. High octane gasoline isn’t more powerful, it simply offers better resistance to engine knock. Lower than needed octane is a big penalty from knocking and/or spark retard, but higher than needed octane gives no benefits. Sounds odd, but it’s true as described below. Premium gasoline does have some benefits even to a car designed for regular, but those benefits aren’t from octane. They are from some other characteristics which are described at the very end, DI and additives. Let’s talk octane first.
Two main factors set octane requirement: compression ratio and spark advance. Compression ratio is a design feature of the engine, with higher ratios giving better performance, but also requiring higher octane rating. Corvettes need premium gasoline because they are high compression ratio, which requires high octane. Best performance in any given engine is at a particular spark advance, and going in either direction makes poorer performance. But while it costs performance, less than optimum spark advance does have the advantage of lowering octane requirement. So your knock sensor can compensate for low octane fuel by retarding the spark, at a cost in performance. But the reverse is not true. Once octane is high enough to allow optimum spark advance, more octane doesn’t help, because greater than optimum spark advance does not increase performance.
The Corvette gasoline spec is 91. There is some variability in engine response depending on a myriad of other characteristics including engine age, but it’s safe to say that benefits of 93 versus 91 are small, and 94 versus 93 are nil. You can make similar comments about the benefits of greater than 87 octane in a normal car. Its compression ratio is lower, so it can get to optimum spark advance on 87 octane. Running 93 octane will not help turn it into a Corvette, because it doesn’t have the compression ratio to utilize the higher octane.
Bottom line on octane is that benefit of being over manufacturers recommendation is slim to none. The only three things that can cause you to get significant benefit from going higher are: 1) a 100,000 mile engine probably needs a couple of numbers more than new due to various irregularities in an old engine, 2) if you live at high altitude, a couple of numbers over normal spec are usually needed, or 3) if you do major engine modifications to raise compression ratio.
Other issues are a detergent additive package for valve and injector cleanliness, a reliable quality control system, and good DI, drivability index, a measure of how well the fuel evaporates. All majors are roughly equivalent in those areas, and most premium gasolines have more detergent and better DI than most regulars. There are shades of gray differences in additives, but once you are with a major oil company, you need careful tests to see them. All majors (including my own) have had quality control lapses, usually with sulfur (causes odor, emissions, and gas gauge problems), particulates (plugs filters prematurely), and/or water (the worst of all, and can devastate an engine, but this one is almost unheard of with the majors). But when the rare lapse does occur, we quickly correct the problem, including any damage it may have caused. When you buy from the grocery store, or Wal-Mart, or a convenience store, you are much more exposed. Some of the time, those places buy from the majors, and their gas is perfectly OK. But all too often, they buy on the spot market, the cheapest stuff that happens to be floating by on a barge. This gives you higher probability of a serious quality control incident, and also exposes you to poor additives and DI. In the short term, you’d never notice lack of detergent additives, but over time, you engine will foul. DI symptoms are subtle, mostly a rough warm up period, but poor DI also tends to foul the engine, especially if it is short on detergent. So you have to ask yourself, do you want to fuel a $50,000 car from the lowest bidder.
Anyway, at the very end of this tome, I’d advise you to set you minimum standard as being at least recommended octane, from one of the majors. Once you are at that point, differences become small. Does 93 versus 91 or 94 versus 93 make much difference? Probably not, unless you live in the mountains or have an aging engine. Is premium worth it in your regular car for the slightly higher additive concentration and slightly better DI if you don’t need the octane? You have to make that decision. There are benefits, but you are into small stuff. It’s kind of like Mobil 1 versus normal oil. Sure, Mobil 1 is very slightly better. It’s also $4 versus $1 per quart. But that’s another long post, and I’m out of energy for now. |
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| leon270 |
| Good to hear that a lot of X owners have been using 87 Octane. I have a 2004 X and been using premium ever since. with the gas prices here in SF hitting $3.47 highest and $2.95 lowest...will be wise to fill up for 87. Thanks guys for doing the development test on X. |
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| anjan |
Hmm. Let me see...I usually fill up around 15 gallons. I'll save 20 cents per gallon by going with 91 instead of 87. That comes to around $3 per fill :eek: What have I been doing? With my three fills per month, I'll save a whopping $9 - and an astronomical amount of $108 per year :bonk:
Especially since the price of gasoline is going up, I can save even more because the price differential between the grades increases too! :rolleyes:
Its simply amazing that people buy a $40000+ vehicle and there is so much argument about whether you can save $3 per trip to the gas station!!! And the argument is even better to watch since there are VERY few vehicles that ABSOLUTELY WILL stall with 87 octance because most vehicles/engines come with knock sensors that retard ignition timing to prevent knocks. This is a thread where people come up with crazy reasonings to assert how MDX can run on kerosene but for those with an open mind as why Pilot and MDX have different requirements for fuel (obviously, since these are TWO COMPLETELY DIFFERENT vehicles) here's the reason why -
quote:
When it came to the engine, the Pilot team's job was to replace some of the premium elements of the MDX's excellent 3.5-l V6 and tune the powerplant for fuel economy and smoothness as opposed to off-the-line performance. The three-rocker setup for the variable valve timing system was replaced with one based on two rockers per cylinder, and the dual stage intake system was jettisoned. In its place a new intake and exhaust system was developed by Honda R&D Americas (Raymond, OH) to optimize the power characteristics of the modified engine. (Though Honda has stated in the past that it has no intention of moving fundamental engine development outside of Japan, this project clearly shows that the powertrain staff in Ohio is increasing its capabilities.) According to Frank Paluch, the Pilot's chief engineer, "The low- and mid-range rpm are completely different than the MDX, which has a flat, broad torque curve. The Pilot's torque curve is more gradual but it peaks out in the same area." Knock sensors were also adjusted so the new SUV could avoid the premium fuel diktat of its upscale predecessor. The result: the Pilot achieves fuel economy of 17 mpg in city driving and 22 mpg on the highway, peaks out at 240 hp and runs on regular fuel.
In the end, its your vehicle, run it on 87 and the ECU will adjust to the octane. To me, personally, its not the worth $9 a month. |
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| anjan |
| Addendum: For those thinking the Pilot and MDX engines are the same, find the hp and torque curves and explain to yourselves why there is a stark difference. MDX has a mesa torque peak, Pilot has a sharp peak. Pilot delivers 250 lb-ft at 4,500 rpm. MDX delivers the same torque at 3500rpm. |
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| DaleB |
quote:
Originally posted by anjan
Addendum: For those thinking the Pilot and MDX engines are the same, find the hp and torque curves and explain to yourselves why there is a stark difference. MDX has a mesa torque peak, Pilot has a sharp peak. Pilot delivers 250 lb-ft at 4,500 rpm. MDX delivers the same torque at 3500rpm.
Could have to do with the cam grind too. But more likely the ECU set up, you think?
Compression ratio is a much closer animal to octane requirements in any case. |
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| anjan |
Yeah, you are right I think. Keeping in mind that they built MDX and first and diluted it down to the Pilot, they did a lot of changes even with the ECU. Since the MDX ECU also gets data from the AWD, Grade Logic, and Drive-by-Wire throttle, changes were made to the ECU programming. ECU, in turn, passes this information to the knock sensor, which also was tweaked to allow for faster detonation (87 burns more easily than 91 - and that's why the timing of the ignition is retarded when the knock sensor detects less than recommended octane level).
Given the configurability of the Honda engine systems, you could arguably adjust the ECU and knock sensor to bring it down to Pilot's fuel specification. I'm not about to try that to save $3 per tankful :2: |
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| DaleB |
quote:
Originally posted by anjan
'm not about to try that to save $3 per tankful :2:
I would not either. But I don't see a big problem using lower grades 87-89 (quality gas) for everyday low performance driving, especially during these times.
And for families who depend on one car M-F primarily for everything, $3 a tank is probably not chump change, esp. at $3 a gallon. |
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| anjan |
quote:
Originally posted by DaleB
I would not either. But I don't see a big problem using lower grades 87-89 (quality gas) for everyday low performance driving, especially during these times.
And for families who depend on one car M-F primarily for everything, $3 a tank is probably not chump change, esp. at $3 a gallon.
Oh absolutely. For me its three fills a month so it doesn't amount to much. |
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| SRSEN1999 |
| I only use 91 octane (premium) gas on my MDX & TL, because I don't want to take any chances of ruining the vehicles. |
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| Silver01MDX |
quote:
Originally posted by Dr. Ken
Always premium. I know I probably don't need it, but it just seems to run better with the high test stuff. Besides, I am a stickler for following manufacturer's recommendations.
I agree with Dr. Ken here. My wife and I had discussed it, and I run 87 octane in my Accord, but it is older and I just don't care about it as much as the MDX. I run 91 octane only in the MDX. I swith between Chevron and Maverick depending on where I am at the time (in town). I know that Honda reccommends a minimun of 87 in the older model cars (like my 94 Accord), but I think they reccommend a minimum of 89 now. You engine will thank you for the premium fuel vs the mid-grade. Its all preference..:D |
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| DaleB |
I always thought regular was 87. Have not noticed the recommendations to that detail.
Also, remember that compression ratio is the main determinator of octane requirement. Not the only one, but certainly a major one.
I say this because I notice the newest Accord V6s have Honda's recommendation to use 'regular' fuel.
Compression ratio is 10.5:1 against the MDX's 10:1.
Maybe if there were an equivalent Acura model it might come with a premium fuel recommendation? Just a thought... |
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| SilveradoMDX |
quote:
Originally posted by goode9100
Do any of you used 87 or 89 octane gas or only premium?
You receive the best responses from everyone responding to your thread.
The fact is, both statements are true. With its sophisticated computer-controlled engine-management system, your MDX can, technically, run on regular unleaded grades of gasoline. But this should be the rare exception say, if you are in the middle of no-where and no other gas is available. Using regular fuel for prolonged periods, especially during extreme operating conditions such as high speeds, climbing hills, or towing, can cause damage over time. Per the manual, your vehicle is designed to operate on premium unleaded gas (pump octane number 91 or higher). Just like Mom and Dad, when it comes to most other things in life, your owner's manual knows best regarding the proper operation of your Acura.
Since buying my 06 MDX, I been filling it up with premium though in time, I may switch to regular but the percentage of using regular gasoline would probably be 25% or less. Like all of us, we can't eat all healthy foods all the time. |
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