So on my trip to myrtle beach last week I noticed that my odometer was off from my mapquest directions and mile markers. Just to be sure, after filling up and resetting the trip (both me and my dad in his car and uncle in his) after a while, I checked. I had 98.4 miles on my trip and they both had 94.5. I set my cruise at 70 and asked my dad to pace me. He said he was only doing 66-67. Anyone have this issue? I know its not a huge deal, but it would come into play when I have say 60,000 miles in all reality, I had only gone less than 58,000 (warranty would be up early).

I have an appointment to have it looked at next week. Would this be something they can adjust through the PCM or a reflash. I just had the latest reflash done 2 weeks ago to fix the bouncing idle with a/c on.

 

You didn't change your tires or nothing right? I guess I have this problem too but they stated all cars are off a little bit. Not 2k miles though.

 

Tires are stock. I know that would affect this. I only have 3k miles on the car, but with being off by 4%, when the miles get higher, it will be off by that much. I understand there is a cushion there to be off by, but I feel like that is a bit much.

 

Yeah, 4% is a bit much. It really shouldn't be more than 1%. I'll have to check mine. I haven't noticed anything yet.

 

Definitely get that checked. GM typically has some of the most accurate speedos on the market.

 

i always thought the speedos were made to be most accurate at 55, bc they really dont care about anything over
i would check it at 55, and see what happens

 

Well I took the car in today and they did exactly what I thought they would do, hook it up to the OBDII and verify that it reads the same as the speedo. I knew that it would. The PCM is feeding them both. My argument was that this is inaccurate. They said they can't do anything till there is a new reflash. I'm sure this won't happen for a while. Not a big deal really but not accurate.

My guess is that anyone with an '06 with the most recent flash (I believe it was dated in June sometime to fix bouncing idle with a/c on) will have this problem. Anyone else check this yet? You can't really check it unless you are traveling long distances and measuring against mile markers or another car's odometer or speedo.

 

how old is your dads car?

 

this happens with mine. i confirmed it when i was driving home from a show with my girl, she said she was going 72-73 on cruise control, i was doing 75-76. that would mean i have about 760 extra miles on my car than i should have with 19,0xx on the clock. WTF!

at 100,000 miles, the actual reading should be 96,000 if this continues without being resolved.

 

Could be your dad's car is off, not yours? What does he drive?

 

My dad's car is a 2001 Grand am. My uncle who had the same as my dad drives a 2006 Saturn Vue. I doubt mine was right and both of theirs were wrong.

 

exactly the reason I want this fixed. It could come into play with warranty claims.