2016 GMC Sierra 1500

Mark Kennedy · February 21, 2018

I've got a 2016 GMC Sierra 1500 with 16 inch wheels. {{Updated 17 inch wheels Thank you Leevon }} If I were to upgrade my truck to a 20 inch wheel or larger would the truck computer automatically compensate for the larger wheels? When it comes to the speedometer. Or would I have to have the speedometer fixed to give proper mile-per-hour. I don't want to guess how fast or slow I'm going? Thanks

a_salazar08 · February 22, 2018

1. There is no way for the computer to automatically know what size of tire you are running. The stock tires for a 1500 is usually about 31", so that's what it's programmed to. It calculates the speed by resolutions. You will need to buy a programmer to adjust it. (diablo, hyper tech, etc.) There are ones for speedo-only and others with more features.

2. Remember, it's about the diamter of the TIRE, not the WHEEL. If you got a new wheel tire package where the wheel is bigger but the tire is smaller (to maintain near-stock diameter), then you don't need to do anything.

Donstar · February 22, 2018

7 hours ago, Mark Kennedy said:

I've got a 2016 GMC Sierra 1500 with 16 inch wheels. If I were to upgrade my truck to a 20 inch wheel or larger would the truck computer automatically compensate for the larger wheels? When it comes to the speedometer. Or would I have to have the speedometer fixed to give proper mile-per-hour. I don't want to guess how fast or slow I'm going? Thanks

Check your current wheel size. The smallest stock wheel size is 17". Post your current tire size on a tire conversion website and you will find equivalent diameter tire sizes for larger rims. Or, post your current size here and we can help!.

Leevon · February 22, 2018

I upgraded from the factory 17's to 20's (275/55/20) tires and the speedometer is dead-on. I did update my VIN through GM software to account for the 20's so I wouldn't get any flack at the dealer for warranty. Keep in mind you can only update for factory tires sizes. Any larger tires aren't available with factory software. You'd need a custom calibration loaded from a tuner, or use a handheld tuner.