speedometer accuracy

Did you know that your 2004 - 2007 Chevrolet Aveo might not have an accurate speedometer reading?

I have a 2007 Optra LT and found this out when I hooked up my GPS system and there was a difference of 3 to 9 KMH. I wouldn't have even known there was a problem and you might not either. Spoke to GM head office and my dealer and they feel it is no big deal but I feel it is a safety issue and the speedometer should be accurate.

It seems this issue has been around for a while and no complaints, as you might not even know about it. My dealer though I was nuts when I told them this a week after getting my new 2007 Optra LT.

Check you maybe surprised.

Here is something else I found on a search on the web

Auto Repair Information » 2004 Chevrolet Aveo LS Wagon
2004 CHEVROLET EPICA, OPTRA ALSO INCLUDED. ... Description: SPEEDOMETER ACCURACY 7 TO 9% HIGHER THAN ACTUAL.


GM bulletin reads

Subject: Speedometer Accuracy Higher Than Actual - Keywords IPC miles ,mileage odo odometer offset speedo #PIC3779B
(01/15/2007)

Models:
2004 - 2007 Chevrolet Aveo
2004 - 2006 Chevrolet Epica (Canada Only)
2004 - 2007 Chevrolet Optra (Canada Only)
2005 - 2006 Pontiac Wave

This PI was superseded to add the 2005-2006 Pontiac Wave. Please discard PIC3779A.

The following diagnosis might be helpful if the exhibits the symptom(s) described in this PI.

Conditions/Concern:

The speedometer may indicate vehicle speeds higher then actual. For example, the speedometer may indicate 60 mph at an actual 55 mph.

Note: The odometer accuracy is NOT affected as this is a speedometer ONLY issue.

Note: This is characteristic of the current calibration.

Recommendation/Instructions:

This condition is NORMAL at this time; do NOT replace the IPC for this conditions it will NOT repair this speedometer offset condition.

I bought my Brand New less then 2 months old in to the dealer for the 5th time.

Here are the test of side by side driving with my vehicle

Service Car 20 40 60 80 100
Customer Car 24 48 68 88 106 All speed are in kph

See not accurate at all and no consistancy in the ammount it is out by.

If you own any of these models

2004 - 2007 Chevrolet Aveo
2004 - 2006 Chevrolet Epica (Canada Only)
2004 - 2007 Chevrolet Optra (Canada Only)
2005 - 2006 Pontiac Wave

I would bring it back to your GM delaer and get them to test them as I bet your vehicle speedometer will be off as well like the other people I have spoke to.

If the dealer says you are crazy tell them to read GM Bulletins 3779, 3779A & 3779B as they have know about this since 2004 and yet there still is no fix for this.

Thanks for pointing this out Optraowner. I test drove one and I brought my GPS along for the test drive and you are right the speedometer is off and I showed the dealer and guess what he said the GPS is off and I told him to read this forum and I walked out of the dealership.

Thanks Optraowner you saved me from buying a lemon. :rofl:

GM shame on you for still selling these cars and not letting anyone know about it. :nono:

People I suggest you bring a GPS when you test drive any of these models mention by Optraowner as I thought he was just one of them guys that wasn't happy with the car and was making things up but he was right on with the speedometer not telling the right speeds and GM should do a recall or let you know the problem before you buy or lease these cars.

I think a lot of vehicles are like this. Think of all the vehicles that are going 52 down a two-lane highway. I drive 30 miles per day on a 2-lane highway, and it's amazing how many people are going just a little bit under the speed limit. My '96 Beretta was about 4% over. Bigger tires fixed that :)

I wonder if perhaps it was an attempt to stop casual speeders? It wouldn't be that hard to make a spedometer register correctly, ESPECIALLY if the odometer reads correctly.

No this is a problem and they know about as it has nothing to do with trying to stop speeding as I have tested on many 2007's and they work fine.

GM also has a bulletin dated back to 2004 and they figured no one will notice as how many people own GPS's?

I think a lot of vehicles are like this. Think of all the vehicles that are going 52 down a two-lane highway. I drive 30 miles per day on a 2-lane highway, and it's amazing how many people are going just a little bit under the speed limit. My '96 Beretta was about 4% over. Bigger tires fixed that :)

I wonder if perhaps it was an attempt to stop casual speeders? It wouldn't be that hard to make a spedometer register correctly, ESPECIALLY if the odometer reads correctly.

Update on this junker. Today my 23000KM car 2 years old is getting a the stearing sensor replaced and the Tranny is getting replaced. a 2 year old car needs a Tranny?

GM is having problems because they make crappy cars and there customer service sucks not because of the Economy.

Glad this was a lease car and get rid of it in Jan 2011