| frostyra |
I have stuck primarily with 93 octane fuel, various brands, but have tried 89 octane a few times. Following is the Octane vs. Trip Computer MPG vs. Calculated MPG for several tanksfull (similar combined city/highway driving):
Octane--Comp. MPG--Calc. MPG
---93-----------------------16.00
---89-----------------------14.05
---93---------15.8--------15.37
---93---------16.1--------16.20
---93---------16.1--------15.55
---93---------16.7--------16.18
---89---------16.3--------15.81
---89---------15.1--------14.58
---89---------15.4--------15.01
---93---------15.7--------15.36
---92---------15.7--------15.33
---93---------15.7--------15.70
---93---------16.0--------15.23
There's not really enough difference to shake a stick at, and I noticed NO performance differences, nor did I notice any pinging with the 89. I am currently using 93, but I'm not sure why when I look at the figures. |
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| DaleB |
The BTU efficiency of high octane fuel is actually slightly less than regular.
In otherwords, as you go down in octane, you are using fuel with slightly better combustion efficiency, but the computer is retarding the spark, which will result in less engine efficiency. Regardless of what the pump says, there is a certain amount of tolerance from that number depending how old the fuel is, some small variability in refining, if the fuel truck has some residue of lower octance fuel, etc. etc.
We don't have 93 in my area, so I just run what is labeled 91, and take it as it comes. |
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| BaldEagle |
| We have 87, 89, and 93 in my area. I think the stratagy I'll use with my new MDX is to fill up with 93 when the tank is close to empty, then fill up with 89 when the tank is 1/2 empty, run till almost empty, then repeat the process. If towing I'll only use 93. |
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| Maik |
"I think the stratagy I'll use with my new MDX is to fill up with 93 when the tank is close to empty, then fill up with 89 when the tank is 1/2 empty, run till almost empty, then repeat the process. If towing I'll only use 93."
What is the purpose??
Assuming you fill up once a week you will save a whopping $75 per year! |
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| rvehock |
quote:
Originally posted by frostyra
I have stuck primarily with 93 octane fuel, various brands, but have tried 89 octane a few times. Following is the Octane vs. Trip Computer MPG vs. Calculated MPG for several tanksfull (similar combined city/highway driving):
Octane--Comp. MPG--Calc. MPG
---93-----------------------16.00
---89-----------------------14.05
---93---------15.8--------15.37
---93---------16.1--------16.20
---93---------16.1--------15.55
---93---------16.7--------16.18
---89---------16.3--------15.81
---89---------15.1--------14.58
---89---------15.4--------15.01
---93---------15.7--------15.36
---92---------15.7--------15.33
---93---------15.7--------15.70
---93---------16.0--------15.23
There's not really enough difference to shake a stick at, and I noticed NO performance differences, nor did I notice any pinging with the 89. I am currently using 93, but I'm not sure why when I look at the figures.
Is your combined mileage always this bad? What percentage is city versus highway? My combined readings 50% city and 50% highway are between 18.9 and 20.1 MPG. |
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| AcuraMDX2002 |
I use 93 octane from various stations, and I get approximately 16 to 18 mpg. Virtually all of my driving is city (although, here in south Florida some of the city driving is at speeds of over 50 mph, regardless of postings!). My trip computer usually tells me that I average about 30 mph. Granted, with only 1100 miles on the odometer, this is not the most conclusive data!
Finally, unless someone can convince me that running 'cheaper' gas through this vehicle absolutely will do no harm, I will continue to use 93 octane regardless of results. |
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| BaldEagle |
quote:
Originally posted by Maik
[B
What is the purpose??
Assuming you fill up once a week you will save a whopping $75 per year! [/B]
That will get me closer to the 91 octane requirement per the owners manual.
Hey $aving $75 here and there is the reason I could afford the MDX. |
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| me95124 |
rvehock wrote:
"Is your combined mileage always this bad? What percentage is city versus highway? My combined readings 50% city and 50% highway are between 18.9 and 20.1 MPG."
Maik
I have seen a bunch or posting reporting very poor (<16mpg city/highway mix) mileage results. Do you have some secrets for the rest of us? I am still very disappointed with our overall mileage. On absolutely flat, open road, we can get >20mpg, but usually we get around 15 or 16 (often getting under 14mpg).
Mike |
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| Harry |
me95124
Something is wrong with your X or you are leaving out some details.
As for the use of 87-89 fuel, the knock sensor will only retard the timing with the onset of knocking. This only happens when you jump on the throttle or are pulling a grade.
Try 87 sometime and you will be suprised.
Like the Pilot, the X runs very well on regular. |
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| creese |
| if you want better mileage, next oil change switch to 5w20 as the 02 owners manual suggests. I went from 15-17mpg in the city to 17.5-19. Hard to find oil. I ordered Amsoil full synthetic online |
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| frostyra |
rvehock: my goin'-to-work driving is approx. 80% city & 20% highway, with ~11 traffic lights or stop signs. On straight highway driving, I'll get up into the 24-25 mpg range.
AcuraMDX2002: every time I fill up (unless I'm trying to keep an eye on overall long-trip mpg) I reset the trip computer. For the first 30 miles or so, it jumps all over the place, but then slowly settles down. The highest trip average I have ever noted is almost 26 mpg.
Yes, I do love the X's accelerating capabilities, and take advantage of them often! :2: |
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| edepa |
quote:
Originally posted by creese
if you want better mileage, next oil change switch to 5w20 as the 02 owners manual suggests. I went from 15-17mpg in the city to 17.5-19. Hard to find oil. I ordered Amsoil full synthetic online
I keep reading that the 02 manual says 5w20, but I only saw 5w30. hmmm.
As a newby with only less than a month on the X, i find the gas mileage acceptable but nothing to write home about. I think my ML actually did a little better. Then again, the X engine may need more run in time to get to optimum gas efficiency and i have just under 2000 miles on it. Any one have any recollections on how the economy improved with engine break in? Be interesting to hear. Thanks. (i'm getting in the 15-16 range with mixed driving):21: |
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| DaleB |
quote:
Originally posted by edepa
I keep reading that the 02 manual says 5w20, but I only saw 5w30. hmmm.
As a newby with only less than a month on the X, i find the gas mileage acceptable but nothing to write home about. I think my ML actually did a little better. Then again, the X engine may need more run in time to get to optimum gas efficiency and i have just under 2000 miles on it. Any one have any recollections on how the economy improved with engine break in? Be interesting to hear. Thanks. (i'm getting in the 15-16 range with mixed driving):21:
A change in the oil viscosity recommendation was incorporated with an updated owner's manual in mid-2002. |
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| edepa |
quote:
Originally posted by DaleB
A change in the oil viscosity recommendation was incorporated with an updated owner's manual in mid-2002.
dale, what was the updated version? the 5w30 i assume? mine had a build date in late May. |
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| DaleB |
Mine had a mid April build date.
The change was right around that time I think. The back of my owners manual shows a print date of 12-01. |
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| frostyra |
A-HA! The plot (and oil) thickens! I wonder if the 5W-20 was a misprint in the '02 manual ('01 was 5W-30) and Acura finally caught it, or if they had problems and figured they ought to go back to good ol' 5W-30? Either way, Acura ought to let all owners know that the recommendation is now 5W-30 -- shouldn't they?
I wonder what the service manual says. If it said 5W-20, has it, too, been changed? |
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| ByeByeChrysler |
I agree with AcruaMDX2002, as long as a cheaper gas does no harm to the engine.
Will using a cheaper gas cause the engine to sound sluggish?
Remember the old pinging sounds of 4 cylinders. |
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| DaleB |
That's why you have knock sensors and a computer to retard the spark and prevent that. You might still get what's called 'trace ping' under really heavy loads.
But it should be only brief and infrequent.
Hard pinging is a real problem and could do some serious damage. |
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| Harry |
frostyra
Just checked my new Factory Service Manual. It specifies 5W-20
I just did my 1st oil change @ 3800 mls and my average mpgs is noticably better and thats with Mobil 1 5w-30.
Its 90 today and I feel better that I've got a 30 lubing my baby.:cool: |
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| DaleB |
Apparently there is a recent change to the manual not specifying 5-20 anymore.
I will go the 5-30 route for sure! |
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| me95124 |
creese wrote:
"if you want better mileage, next oil change switch to 5w20 as the 02 owners manual suggests. I went from 15-17mpg in the city to 17.5-19. Hard to find oil. I ordered Amsoil full synthetic online"
We have 6000 miles on the X and have changed the oil twice. I used 5w20 both times. It actually says on the outside of the oil container that it is recommended by Honda and Ford.
Our acceleration is not great, but the dealer says it's fine. By the way, since the mileage has been poor, we've consciously tried to not accelerate. I guarantee you that I drove my old '87 Jeep Cherokee a lot harder and still got 18MPG (straight 6, larger displacement).
I'm open to any suggestions, but getting 21 MPG is not achievable on the highway anymore. Of course, the dealer says he can't address gas mileage.
Well? |
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| msu79gt82 |
quote:
Originally posted by ByeByeChrysler
I agree with AcruaMDX2002, as long as a cheaper gas does no harm to the engine. Will using a cheaper gas cause the engine to sound sluggish? Remember the old pinging sounds of 4 cylinders.
How can anyone really know for sure if using a lower octane gas will harm the engine unless they use it for an extended period of time and notice that the engine has been harmed!!?? Then it will be too late:rolleyes: Those who regularly use a lower than recommended octane are conducting an experiment for the rest of us. Good luck. |
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| Harry |
Hello me95124
You have 6000 miles on your X and you have changed your oil twice? How many brake-in miles before your first oil change? Are you aware that your machine comes with special breakin fluid to let the rings seat in properly.
If you have changed this fluid to early and are using a synthetic oil, your top end is not going to break in properly.
I have a backround in engine building and development and I am fluent with Honda engines and I can tell you that it takes a good 10,000 miles for this type of motor to be fully broken-in. I am not saying that the original brake-in fluid should be run for 10,000 miles, but it should not be changed sooner than 3,500 minimum.
Also after the first 500 to 600 mile you should progressively run the motor harder and bring the revs up higher and higher followed by the closing of the throttle which sucks oil up into the rings. You want the rings to seat-in as they say and if you baby the motor for the entire brake-in period this process will be compromised.
Hope this is helpful |
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| DaleB |
quote:
Originally posted by Harry
Hello me95124
You have 6000 miles on your X and you have changed your oil twice? How many brake-in miles before your first oil change? Are you aware that your machine comes with special breakin fluid to let the rings seat in properly.
If you have changed this fluid to early and are using a synthetic oil, your top end is not going to break in properly.
I have a backround in engine building and development and I am fluent with Honda engines and I can tell you that it takes a good 10,000 miles for this type of motor to be fully broken-in. I am not saying that the original brake-in fluid should be run for 10,000 miles, but it should not be changed sooner than 3,500 minimum.
Also after the first 500 to 600 mile you should progressively run the motor harder and bring the revs up higher and higher followed by the closing of the throttle which sucks oil up into the rings. You want the rings to seat-in as they say and if you baby the motor for the entire brake-in period this process will be compromised.
Hope this is helpful
Interesting points, Harry, Perhaps me95124 (wasn't that a TV show?) is saying he changed at 3K and again at 6K. I run Mobil one and plan my first change at 3750, and about the same interval every time. I always broke in my engines the same way you do. I am used to doing it in one session on a wide open road, where I could decelerate and accelerate repeatedly. Doing progressively higher RPM, and moderately fast acceleration, and then coasting down with the throttle closed.
In the carb days it was even more effective because deceleration would also suck some amount of fuel past the rings, and it is thought that would speed up the seating process. With FI the fuel is effectively turned off with a closed throttle.
In any event, with modern sports cars coming off the line with synthetic in their crankcases I think around the 4000 before the first change should be fine for either premium oil, syn or non-syn. But I would not do it sooner either.
The other half of the formula I follow for good engine perfomance and long life, is to drive it like it still has less than 500 miles on it until the engine is fully warmed up. |
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| msu79gt82 |
quote:
Originally posted by Harry
You have 6000 miles on your X and you have changed your oil twice? How many brake-in miles before your first oil change?
The manual makes no mention of any break-in oil (I am not denying there is some just the manual ignores it) and states you are to follow the recommended maintenance plan. Hence the manual states the first oil change should be at 7500 miles for normal driving conditions and at 3750 miles for severe driving conditions. My service advisor strongly recommended we follow the plan and since we qualify for severe driving conditions (on a couple of points) we had the oil changed at about 4000 miles. |
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| Harry |
Hey DaleB
Oh,,,,, the OLD days of Carbs. O yaaaa
You are correct about the fuel wash in the upper end under closed throttle when the manifold spressure would go through the roof, but fuel injection is better for the same reason.
I remember years ago when a BMW race engine builder use to fire up a flat twin dry, thats right, dry with no lubrication on the pistons and rings and run it at 3 to 4000 rpm for about 30 seconds before shutting it down.He would then disassembled the top end, carefully wash the parts and reassemble the rings in the same clocking as the dry run. The theory , and consistent 1st place finishes proved it worked was to get a near perfect seal.
I was impressed and learned a lot
I also use Mobil 1 and have for years but only after breakin.
Harry
msu79gt82
Sounds like you did it right. I also did my first oil change at 4000 (varied) miles.
Makes ya feel good ayyy.
Harry |
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