5% odometer error

[RSO 34]

I recently noticed that my odometer is off by 5%, meaning that it is logging 5% more miles than I am actually driving. Acura claims that a 2-3% margin of error is acceptable.

The car has no mods and has OEM tires.

Three questions:

1. Any idea why this happened all of a sudden?

2. Any suggested remedies and costs?

3. Should I even bother to try to correct?

Thanks.

Bob

 

[4AU4LIFE]

I too noticed the same thing when my wife and I took a trip driving seperate cars and I put on more miles than she did?
What gives?


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ALL NSX
92 RED/BLACK 5-SPEED

 

[gavin]

Guess that means its time to upgrade to bigger tires!!!

A 18/19 combo would fix that problem pretty quick!

Just keep one thing in mind though, on the freeway, you will be traveling faster than you are going.... (Think about it for a while)

 

[Number9]

Originally posted by gavin:
Just keep one thing in mind though, on the freeway, you will be traveling faster than you are going.... (Think about it for a while)

That would be a neat trick. Don't you mean to distinguish between actual vs. indicated, or are you a proponent of the "many worlds" interpretation of quantum mechanics?

 

[nsxtasy]

Is it possible that your measurement technique is slightly off? (Highway signs are occasionally placed at intervals that are wrong.)

Also, if your rear tires were worn down close to the treadwear indicator bars at the time of the test, that could account for 2 percent of error, moving it from 3 percent (acceptable) up to 5 percent.

Finally, if you use '94-01 size OEM tires on a '91-93 NSX, that would add 0.6 percent to the error.

Hope this helps.

 

[BostonNSX]

usually when would this symptom starts? howcan I get this diagnosticed to check if I have this problem

 

[4AU4LIFE]

Unfortunaley none of those solutions relate to mine. I was running stock size tires and wheels. Was using the mileage example off the odometer/tripmeter of both cars starting from the same point and ending in the same point.
Doesn't really matter anymore because I went +1 size up on tires/wheels.


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ALL NSX
92 RED/BLACK 5-SPEED

 

[nsxtasy]

Originally posted by 92NSX:
Doesn't really matter anymore because I went +1 size up on tires/wheels.

Changing the size of your wheels and tires doesn't necessarily change your odometer and speedometer accuracy. Ideally, you should select tire sizes (even with bigger wheels) that have the same outer diameter as stock, leaving your gauges unchanged. If the outer diameter is larger than before, your odometer and speedometer will indicate less. If it's smaller than before, they will read higher, as in RSO's example.

[This message has been edited by nsxtasy (edited 06 October 2002).]

 

[RSO 34]

Ken,

I have a '96 and am running the Potenza RE010's.

The mileage was compared to a combination of highway signs and comparisons to other NSX's as well as one of my other cars that seems to be extremely accurate.

The tires are getting a little worn now but I noticed it before running them this bare. At the time it started, I probably had about 70% tread left on the rears. Strangely, it never happened before I changed out the clutch this summer. The first trip I took after that my odometer was off. I know the clutch should have no effect but it was strange that the odometer was accurate prior to that change.

Should I assume based upon your tire inquiry that my odometer will get progessively less accurate as the rear tires begin to wear? I am going to put a new set on to head to NSXPO so I will check my mileage with the other cars on the way down to see if there is any change in the margin of error.

Thanks for the input.

Bob

 

[Ag NSX]

Are odometers and speedometer measurements related? Meaning, do they both use the same measuring instrument or do they use separate ones? If they are measured by one instrument then if you driving at 60 mph for 5 minutes, your odometer should go up by 5 miles regardless of tire size right?
Maybe you can get a GPS in your car and see how accurate the speedometer is. Maybe it's off by 5% too.

What Ken is saying is that as your tires wear, your tire circumference gets smaller, so you will actually travel even less distance than what your odometer is saying now, making it off by even more.

 

[4AU4LIFE]

Actually I do have a portable GPS that I use regularly. I have often measured my speed against it and appears to be dead on.

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ALL NSX
92 RED/BLACK 5-SPEED

 

[nsxtasy]

Originally posted by RSO 34:
Should I assume based upon your tire inquiry that my odometer will get progessively less accurate as the rear tires begin to wear?

As the tires wear, the odometer will read higher and higher. If it was reading high before, it will get less accurate; if it was reading low before, it will get more accurate. (Gee, am I sounding like a lawyer?

)

The difference in outer diameter between a new street tire and one that's worn down to the treadwear indicator bars is about 2 percent (tread depth changes from 10/32" to 2/32" on a tire that's roughly two feet in diameter), so tire wear can account for a swing of 2 percent in your speedometer and odometer readings.

 

[RSO 34]

You are beginning to sound somewhat lawyerly, Ken, but you can complete the transformation by telling me who I can sue because of the mental anguish sustained by my NSX who is being forced live with the fact that she is not as old as her odometer says.

 

[Vytas]

I make several trips from Monterey to Los Angeles every year. When I had my '96 Accord Coupe, my trip meter showed 355 miles one way. This was consistent throught the five years that I owned the car. When I got new tires, the trip distance didn't change at all.

Get this. I sold the Accord and got an '01 GSR. Now my trip meter shows 327 miles one way. I've made the trip to Los Angeles three times since I got the car and it's a consistent 327 miles.

Any reason why there would be a 28 mile difference between the two cars? If it was a few miles, I can understand. But 28 given that it was only a 327-355 mile trip? Next time I go, I'll use my GPS and get an accurate distance reading and see which car is more accurate.

[This message has been edited by Vytas (edited 07 October 2002).]

 

[nsxtasy]

Originally posted by Vytas:
Any reason why there would be a 28 mile difference between the two cars?

Odometer inaccuracy, perhaps?

(I'm assuming you were using stock size tires on both cars.)

 

[BostonNSX]

Originally posted by nsxtasy:
Odometer inaccuracy, perhaps?

(I'm assuming you were using stock size tires on both cars.)

Thats a bit to much......I think dun u think so?

in the long run.. its gonna effect the resale value on mileage.. (depreciate for some extra mileage which not even exist? )

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the art of chasing down my friend's white 3000gt at com. ave

NSXCA # 1690


[This message has been edited by BostonNSX (edited 07 October 2002).]

 

[nsxtasy]

Originally posted by BostonNSX:
Thats a bit to much......I think dun u think so?

Yes. (I didn't mean to imply that a 9 percent odometer error was acceptable. It's not.)

 

[Nsxotic]

Originally posted by 92NSX:
Was using the mileage example off the odometer/tripmeter of both cars starting from the same point and ending in the same point.

Did it ever occur to you that the 'other' car may also have a descrepency? Wouldn't that account for the difference? How can you use something else that is inaccurate to determine the accuracy of your car? Your method is definitely NOT the best way to tell what's off. You need to find a known, 'measured' distance and then drive it to see what the result is.

 

[BostonNSX]

what about the GPS mentioned awhile ago. would it give an accurate #?

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the art of chasing down my friend's white 3000gt at com. ave


NSXCA # 1690

 

[Vytas]

Originally posted by Nsxotic:
Did it ever occur to you that the 'other' car may also have a descrepency? Wouldn't that account for the difference? How can you use something else that is inaccurate to determine the accuracy of your car? Your method is definitely NOT the best way to tell what's off. You need to find a known, 'measured' distance and then drive it to see what the result is.

I plan to measure the distance traveled with my GPS on my next trip. I know that using two different cars to measure distance is not an accurate method. The point of my message was the big disparity between two cars (28 miles?) on a 350 mile trip. Regardless of what cars are used, there shouldn't be such a big difference. The GPS will tell the truth.

 

[sjs]

I'm not sure the GPS will do the trick. Does it accumulate total distance traveled, or just indicate the distance from point to point regardless of route between them? Some hand-helds only do the latter.