Speedometer Calibration

I took my 2004 Avalanche into Woodland Hills Pontiac yesterday to have routine maintenance and asked that my speedometer be calibrated for my new larger wheels. I was told that it was unnecessary as the truck will automatically recalibrate, is that true or was I feed a line?

Automatically calibrate? How? Does it have GPS integrated with the ECM? I smell major BS.

If you got larger wheels and lower profile tires then the overall tire wheel diameter may not have changed, otherwise this sounds like baloney. I know that aftermarket programmers like Hypertech have the ability to account for changes in wheel/tire sizes and rear axle ratios. You could try checking the odometer using roadside mile markers.

Ed B.

As you were not asking for a free service why would the dealer turn down a oppourtunity to make some money?I know that thru the Tech 2 you have a range of tire sizes to select (range was not that great a most the original and 2 other very close options).Maybe GM made this a automatic feature as the years Iam refering to are late 90’s.

Why would you need larger wheels on an SUV? They’ll just get chewed up when you go off road.

[b] Why would you need larger wheels on an SUV? They'll just get chewed up when you go off road. 


How many SUV go off road other than when they miss the driveway after a night at the pub?

I know, I was being facetious. Obviously anyone who decides to get bigger wheels (18’s or better) on their SUV is an image-obsessed poseur. I’ve had people ask why I only have 15 inch wheels (but 33 inch tires) on my Bronco. Nobody understands that sidewall flex is a good thing when you’re not on pavement.