Speedo and Larger Tires Q

[timgco]

For those that have gone to a lager tire size (more than just 32" to 33").

I am wondering what the deal is to recalibrate the speedo on the H3.
My sig. other wants 35's.

As far as I know, Hypertech or the other power programer manufacts. have not done anything as of yet. On my H2, it was easy to change with the Hypertech programer.

Aynone also have an educated answer about how far off the speedo wil be @ 35mph, 55mph, 75mph?

Thanks,
Tim.

[timgco]

For those that have gone to a lager tire size (more than just 32" to 33").

I am wondering what the deal is to recalibrate the speedo on the H3.
My sig. other wants 35's.

As far as I know, Hypertech or the other power programer manufacts. have not done anything as of yet. On my H2, it was easy to change with the Hypertech programer.

Aynone also have an educated answer about how far off the speedo wil be @ 35mph, 55mph, 75mph?

Thanks,
Tim.

[f5fstop]

Really depends on how much larger you go over 33" and if the vehicle was programmed for 32 or 33 inch tires.
I can say that my speedo is off 2 mph on stock 33" inch tires, and it is programmed for those tires. At 70 on the speedo, I registered 68 with two different GPS units. This is well within Fed specs for speedos.
The BCM may not be able to be programmed for anything larger than 33" tires.

[timgco]

To clarify, we have the adventure package with the 33" Dueler AT's wich I believe are 32.8" and the new tires would be 34.6". So at 1.8" difference my guess without actually testing with a handheld GPS unit would be ??? I have no idea. But those are the sizes. The dealer tells me that there is no calibration option and that there was nothing done between the standard 32" to 33". So I wasn't sure about that eitehr.

[H3 Hummer]

I like the pimp my ride approach.

Drive down the road and have your friend yell out the window when he gets to 35 , 55, 75. Get a 3x5 card and write down the differences.

Example: 75 real life ='s 72.

You have to see the correct pimp my ride episode to get it but really I think if you just multiply by 5% you should be very close.

So 75 mph would be real life almost 79.

[YellowH3]

Try this. You can enter your current tire size, along with the new tire size, and it will let you know how much the speedo will be off (approx)Tire size calculator

[timgco]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by YellowH3:
Try this. You can enter your current tire size, along with the new tire size, and it will let you know how much the speedo will be off (approx)Tire size calculator </div></BLOCKQUOTE>

nice find. Thank you all.

[WPBGUY]

What size is the tires for the Lux package /wo adventure series? 30"??

[timgco]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by WPBGUY:
What size is the tires for the Lux package /wo adventure series? 30"?? </div></BLOCKQUOTE>

look on the inside of your drivers soor sill and you will see your tire size with psi measurements. You should have 265 tire wich is almost a 32", but I think is closer to the 31".