waveoff

iTrader: (11)

The previous owner of my car evidently had the rear end serviced repeatedly by the dealership (3 different times). On one of those occasions, the stock 2.73's were replaced by 3.23's. According to the service records, this looks like it occured at 32130 miles in 2001 (assumption). When I bought my car in 2005 it had 97,000 miles on the odometer and the speedo was way off. After I learned that this was caused by the gear swap I started to wonder if the car really had 97,000 miles on it. The car drove, felt and looked like it had less on it. From what I've been reading, a gear swap will not only cause the speedo to be off, but may also cause the odometer to be off as well. I have since corrected the speedo error with an HPP3.

My question is this. I corrected the speedo error at 98,000 miles. If the 3.23's were installed at 32130 miles, and nothing was ever done to correct the speedo error, what would the ACTUAL mileage be at 98,000 miles? My math skills are horrible and I'm sure there's a formula to figure this out. If someone has an answer to this math question please post up the formula and/or steps taken to figure it out. Thanks in advance.

waveoff

iTrader: (11)

Hmmm...I'm still trying to figure out how to figure this out. It's consuming me. I'm spending all of my internet time Googling for an answer. I think I'm on the verge of figuring it out. Does anyone know the answer to the following...

Say I never corrected the speedo and odometer error using the HPP3. My car was originally equipped with 2.73's which were later swapped for 3.23's. If I drive my car one ACTUAL mile (as measured by mile markers), how many miles will my odometer THINK I travelled?

I suppose I could undo the HPP3 correction and just go test it myself. However, there aren't any places near my house where I can just stop on the highway at a mile marker and drive to the next mile marker...too much traffic. With the mathematical method I would get more accurate results.

NHRAMAN

iTrader: (1)

Sorry,can't help you but I bet you have much less mileage on it than it reads...that's great...

MattIROC

iTrader: (19)

when you move to a lower gear, your speedo will read higher than what you are doing, therefore more miles racking up. I'd say your speedo is about ~5ish mph's off from 2.73's to 3.23's. I dont know of a formula to figure this out, I'd say thousands of miles more though if it was done around 32k and its at 98k when you got it. If you go up on the gearing (ex: 4.10's to 3.42's) your speedo will read slower than what you are doing, making less miles rack up. (Not sure if you knew that or not).

78LT383

Your car has about 87803 miles on it now.

The 32130 should be considered correct as far as you know, right? So, the actual miles traveled between 32130 and 98000 is:

(98000 - 32130) * (2.73 / 3.23) + 32130 = 87803 miles.

waveoff

iTrader: (11)

Thanks a bunch for helping me figure this out! I'm pretty certain that the 32130 is correct. The car was in for ring and pinion service at 32130 and at 30363...so I guess there's a possibility that it might have had the 3.23's put in at 30363. Using the formula you provided, depending on when the 3.23's were put in, the car had somewhere between 87529 and 87803 miles on it before I corrected the speedo. Here's the dealership claim history...

CLAIM HISTORY
R.O Date R.O Number Type Labor Operation Odometer Reading
05/29/2001 176407 # C1080 - WEATHERSTRIP - FRONT DOOR OPENING - RIGHT - ALIGN OR REPLA 35144 miles
05/29/2001 176407 # C1081 - WEATHERSTRIP - FRONT DOOR OPENING - LEFT - ALIGN OR REPLAC 35144 miles
05/29/2001 176407 # R9140 - CHANGER, CD - REPLACE 35144 miles
04/18/2001 174264 # F2383 - RING GEAR AND PINION - REAR DIFFERENTIAL - REPLACE 32130 miles
04/18/2001 174264 # H0127 - ROTOR ASSEMBLY - FRONT - BOTH - R&R OR REPLACE 32126 miles
04/18/2001 174264 # C9021 - BUCKLE, SEATBELT (FRONT) (LEFT) - REPLACE 32126 miles
02/12/2001 170717 # F2383 - RING GEAR AND PINION - REAR DIFFERENTIAL - REPLACE 30363 miles
02/12/2001 170717 D F2383 - RING GEAR AND PINION - REAR DIFFERENTIAL - REPLACE 30363 miles
02/12/2001 170717 # L1200 - SENDER AND/OR PUMP ASSEMBLY, FUEL (TANK UNIT) - REPLACE 30363 miles
02/12/2001 170717 # R9140 - CHANGER, CD - REPLACE 30363 miles
02/12/2001 170717 # K6360 - SEAL, EXTENSION HOUSING REAR - REPLACE 30363 miles
11/22/2000 166784 # F2023 - SEAL, PINION SHAFT OIL - REAR DIFFERENTIAL - REPLACE 29617 miles
11/22/2000 166784 # H0127 - ROTOR ASSEMBLY - FRONT - BOTH - R&R OR REPLACE 29617 miles
01/07/1999 017955 # H2800 - PARKING BRAKE - ADJUST 7811 miles
06/01/1998 273011 I Z7000 - PRE-DELIVERY INSPECTION - BASE TIME 4 miles

Thanks for the info. I was aware of the whole speedo error issue with different gearing and/or tires. Without the HPP3 to correct the speedo, it would should something like 83 mph when I was really doing 70 mph. At slower speeds the error wasn't that extreme.

kenp

iTrader: (9)

I'm having a hard time understanding why a dealer would not have reprogrammed for the different gear.

waveoff

iTrader: (11)

I was wondering the same thing. Maybe the person who had the car before me had a HPP3 to correct the speedo, then returned the car back to stock before getting rid of it so that he could sell his HPP3. I have no clue! On the other hand, the car had 215/55/16's on it when I got it so maybe the previous owner was ignorant about the speedo/odometer being off like he was about the tires being the wrong size. Whatever the case may be, I just wanted to get an idea of how many miles my car MIGHT actually have on it in the event that the speedo was never corrected. If I sell the car I'm not going to try and BS anyone about the mileage...I'll just go by what the odometer says.

99midnightZ

cant you just get a new spedo gear or does it have to be reprogramed for the gears?

waveoff

iTrader: (11)

I suppose you could get a new speedo gear but I got the HPP3 for ease of installation.