2mph off isn't a valid assessment, unless you specify what speed that was noticed at.
It is off by a different amount at every speed traveled. You have to know the percentage differential of the tires then apply that same percentage to your speed.
For instance, if your new tire is 4% different in size, then your display at 25 is off by 4%, the same as when you drive 70 your display is off by 4%.
I don't know which Hypertech thing you have (I'm not looking it up), but I know there is just one that works with the 2008+ models. Your 2012 then should be in the list as long as it was meant for our computer.
Doesn't the Hypertech site list what vehicles that product number works with.
I will then assume the programmer will allow you to input your tire size and will correct it. But if it does not work tire size alone, you must do the math between the two tires and adjust per your percentage differential.
The Hypertech Speedometer Calibrator 732501 is designed specifically for calibrating the speedometer after wheel and gear changes. Hypertech's web site claims it is compatible with your 2012 Chevy Colorado 3.7L.
Speedometer Calibrator - Part #732501 Adjustable Features
Speedometer\Odometer Correction For Tire Sizes 24-54 inches 1/4 inch increments
yes it will allow you to fix spedo error by entering the tire size
i used to do it all the time with my S-10, I had 4 diff sized rear tires.
summer,winter,towing and racing
I adjusted my Colly with my InTune tuner for shorter tires, 245x45x18
I'm 1.03% too slow across the board, (example gps 60, speedo 58). The programmer is listed to work on my truck. I already have a costume tune and can't reach the installer to ask if his tune is locked or if the Hypertech is compatible. I thought maybe one of the tuners would know how these tunes are imputed and if it will except the Hypertech without altering the rest of the my tune.
Ahh.....sorry to input then. You didn't say anything about a tune already on the computer.
Sorry about that.
That's pretty small, almost not worrying about if you're only off by 2mph at 60. The amount the display is off driving in city is barely noticeable isn't it? I guess you can't tell, because it's off. haha