What do i need to recalibrate my speedometer after my tire/rim swap?

[Fless]

So I found the instruction video I watched on the Tech 2 setting tire size and it was a freaking Saab.

I went through most of the pages on my Tech 2 and didn't find anywhere that it would calibrate the speedo off tire size.

Looking for the Tech 2 video, I did see a bunch of aftermarket devices that will reprogram the speedo calibration based on tire size that are a lot less expensive than a Diablo Predator. I think it will still be more than the $100 quote you already have in hand. Sorry for the bad advice on the Tech 2.

I was thinking that I saw tire size options somewhere in the Tech 2 also, but if it's there it doesn't affect the speedo from what I recall. Only has to do with the ABS sensors. I might be wrong.

 

[totalpackage]

So I found the instruction video I watched on the Tech 2 setting tire size and it was a freaking Saab.

I went through most of the pages on my Tech 2 and didn't find anywhere that it would calibrate the speedo off tire size.

Looking for the Tech 2 video, I did see a bunch of aftermarket devices that will reprogram the speedo calibration based on tire size that are a lot less expensive than a Diablo Predator. I think it will still be more than the $100 quote you already have in hand. Sorry for the bad advice on the Tech 2.

Which one would you recommend keeping price in mind. I don’t mind paying 150-200 for the tool. If more than that, I will find someone to do it.

 

[wsteele]

I was thinking that I saw tire size options somewhere in the Tech 2 also, but if it's there it doesn't affect the speedo from what I recall. Only has to do with the ABS sensors. I might be wrong.

I couldn’t even find it for ABS, but that doesn’t mean it isn’t in there somewhere.

The features the Saab supports with the Tech 2 doesn’t even have pages similar on my unit.

 

[wsteele]

Which one would you recommend keeping price in mind. I don’t mind paying 150-200 for the tool. If more than that, I will find someone to do it.

I haven’t used any of the third party units. I have a Diablo Predator 2 and it has a lot of features beyond just tire size. It has some canned tunes, ability to turn AFM off/on, etc. But for the money, finding a local who really knows HP Tuners might be better in the long run.

I would checkout YouTube and maybe see what you think. One guy was talking about a $170 new retail unit he bought used on eBay and discussed the ins and outs of that route.

 

[Fless]

I was thinking that I saw tire size options somewhere in the Tech 2 also, but if it's there it doesn't affect the speedo from what I recall. Only has to do with the ABS sensors. I might be wrong.

On the menus for my '04, it's under Chassis; ABS; Special Functions.

But I'm pretty sure that's just for the ABS, not the speedo.

 

[wsteele]

On the menus for my '04, it's under Chassis; ABS; Special Functions.

But I'm pretty sure that's just for the ABS, not the speedo.

I will check it out, I probably just missed it.

 

[Rocket Man]

I’m pretty sure the Tech2 can’t do it. I could be wrong though, wouldn’t be the first time. Second or third idk.

 

[wsteele]

I’m pretty sure the Tech2 can’t do it. I could be wrong though, wouldn’t be the first time. Second or third idk.

As best as I can tell, with our trucks, it can’t.

I assumed it did as I watched a Tech 2 vid where they explained how to input the tire size into the Tech 2 to update tires specs. Unfortunately it was for a Saab model, like a 2008. Obviously is not the same on GM light duty trucks and SUV’s.

The Saab page was accessed on the first page you get after inputting year, model, etc. It was called something like Special Options and that page gave you the ability to put tire size in, etc. it actually had a bunch of default tires you could choose like Pirelli P0’s, etc., and when you confirmed the new tire size, it updated the speedo calibration.

 

[M Stewart]

I just got a speedo cal unit from Hypertech for larger tires on my Colorado ZR2. Hypertech has been at the tuning game for MANY years (I used one of their chips on my '93 back in the day) and makes good equipment. Looks like $230 for your truck. Here's the link:

http://hypertech.com/InlineSpeedometerCalibrator.aspx

BTW, I've used their gear on GM trucks with gas and diesel engines, tuners and Speedo Cal units with zero issues. All performed as advertised for as long as I had the vehicles and I tend to keep them for 200K miles+.

 

[Floep]

Is it 4 out on all speeds? If so it is only necessary to move the speedo needle on its shaft, small job. On the other hand the difference varies with the vehicle speed, it has to be programmed for different axle ratio or tire diameter with programming tool