Odometer Problems

[we2golf]

I have a 2001 MS-XLS. I wanted to go up a tire size to a 265X70X16 from the stock 255's that came on the vehicle, so before making the change, I started noting RPM/MPH correlations, and comparing highway mile marker distances with my odometer. To my surprise I found that with the stock 255's I was racking up the miles faster on my odo than the mile markers were indicating (about 11.2 miles for every 10 actual). Since I put the 265's on my odo has been right on with the highway mile markers, and I have seen a major drop in the rate of miles I have been racking up on the vehicle. This of course has a major impact on my warranty and the frequencey of service visits to the dealership, as well as the gas mileage I thought I was getting. Has anyone else noticed this? Could the odometers have been calibrated for larger tires than the stock 255's that came with the vehicle?

[ChrisNNewMex]

Not positive, but pretty sure that the XLS's always came stock with the 265's (biggest stock tire on the sports), so, whom ever had it last didnt think the bigger tires were good, went smaller and messed everything up for ya. You might consider talking to the dealer about it messing up your warrenty,milage.... ect. Or you could just go get a set of 31's and run them for as long as you ran the 255's and that should even everything out! lol

Good luck
Chris in New Mex

[we2golf]

Thanks for the reply Chris! I bought the XLS new in Nov. of 2000, and the 255's were on it stock. But I was talking about this to someone I ran into who had a 1999 XLS and they had 265's on theirs. I plan to talk to the dealer about this next visit. Does anyone know if the 2001 XLS's were supposed to have 265X70X16 tires from the factory??
Other than this problem, and the fact that the Stock 255 Yokos, and the stock shocks were shot at 25,000 miles, my wife and I love the Sport. Of course I was more than happy to put on a good set of larger and more aggressive tires(Yoko ATII's), which have been great with the major snow storms we are having here in Pa.
I also was more than happy to slap on a set of Bilstein shocks, which boosted the spring rates a bit and improved the Sports handling.

[Stod]

2001 Sports - LS, XLS, Limited - came with P255/70 R16 mud-and-snow, mostly Yoko Geolanders (some with Bridgestones, I think).

When I moved up to 265/75-16 BFG AT/KOs my speedo slowed by about 2.7 MPH (i.e. actual speed @ 73 showed 70 on speedo).

As far as I know, all MS's have the same speedo gears so your's should have been accurate with the stock tires. Higher/Lower tire PSI inflation may have and effect on MPH reading(??!!), don't know.

Cheers,
Stod

[we2golf]

Thanks for the reply Stod. Indeed tire PSI can effect your Odometer and Speedometer since the tires effective diameter would vary. I did check my tire pressure when I first noticed the Odo discrepancy, and even boosted them a few psi. I had been running them at 28psi, which might have been a little low, so I went up to 32psi. I usually judge my psi setting by the old chalk line treadprint test. I found this to be a good way to match psi, to vehicle weight, to tire characteristics. These are all variables that play into getting an optimum tread "footprint" for a given tire/vehicle combination. Anyway, the slight rise in psi didn't change my Odo discrepancy by much. The 255/70/16's are a 30" tire, while the 265's are closer to a 31" tire. The 265/75's you are running are closer to a 32" tire and definitely should slow your Speedo & Odo down. I have the optional limited slip rear in my 2001, and it is geared lower than the stock diff. I went this route because I do some light towing. I'm sure Mitsu must use a different Speedo gear for this diff. There is a very good set of "Gear/Speed/Power Range/Tire Size" calculators at www.4lo.com. It is like the ones on this site with a few interesting differences.