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I went from 245 to 265 tires and want to get my computer/speedometer corrected. Called my Chevy dealer and the service manager told me GM does not support nor make the adjustment. Told me I would have to buy the equipmnet myself to do it. Does anyone know where I can get this done in Dallas, Tyler or Corsicana TX area?

Thanks
 

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I guess that would give you an excuse to buy a programmer :D . I have 265's and bought a bully dog powerpup from a member on here to recalibrate as well as add some performance to it. You can also check out the superlift tru-speed as well.
 

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Speedo

There is a website that will give you the corrected speed for the tires you run without doing anything. You will just have to see the difference by going slower than your speedometer says you are going. The other option is to buy a chip that will adjust your speedo for the tire size you are running. The first option is MUCH less expensive.....I think the site is "speedometer correction". Good luck. I run 285's and have never had the speedo corrected. I just compensate and go a little slower than the speedo says I'm going....Most of the time!!!!!!
 

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I guess that would give you an excuse to buy a programmer :D . I have 265's and bought a bully dog powerpup from a member on here to recalibrate as well as add some performance to it. You can also check out the superlift tru-speed as well.
Quadzilla and Predator will also correct speedo for tire size.
 

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I just did the same thing when my truck was having the intermediate shaft replaced. They told me it would be 100.00 to reprogram the computer. Bunch of rip-off $hit-heads!
 

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I run 285's and my dealer told me to go by a Hypertech Programmer to fix the speedo. They also said that I should install the lowest HP settings to compensate for the larger tire size. So I bought one and installed it. The truck feels like it did with the stock wheels. The gas mileage is better as well.
 

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I run 285's and my dealer told me to go by a Hypertech Programmer to fix the speedo. They also said that I should install the lowest HP settings to compensate for the larger tire size. So I bought one and installed it. The truck feels like it did with the stock wheels. The gas mileage is better as well.

Ok, not replug it in and put it on level 3. You'll enjoy that much better.
 

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Ok, not replug it in and put it on level 3. You'll enjoy that much better.
That was the first thing I did... :) :) Gas mileage sucked (10 MPG), because I couldn't keep my foot out of it. I set it back to level 1 and I'm back at 18 MPG. Level 3 was fun though...
 

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I'm getting 18.9 highway @ 75 in level 3. You gotta learn to drive again for this new found power. I actually ran it on level 1 for a couple weeks and couldnt stand it so I plugged it back in and bumped it back up. As for fuel mileage, everyone's sucks during the winter months from the winter grade fuel mix.
 

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I went from 245 to 265 tires and want to get my computer/speedometer corrected. Called my Chevy dealer and the service manager told me GM does not support nor make the adjustment. Told me I would have to buy the equipmnet myself to do it. Does anyone know where I can get this done in Dallas, Tyler or Corsicana TX area?

Thanks
Well, with just a small jump in tire size from 245 to 265 I doubt you'll need to reprogram. Stock wheels & tires seem to run a litttle fast with stock calibration. The 245 is about 30.7" tall and the 265 is 31.8" tall, that's only 1" difference. So, before I'd do anything I would check my speed with a GPS with the 245s, then check it again with the 265s. Then if it's off too much you can get it reprogrammed. But, if you are just looking for an excuse to buy a programmer, then forget everything I said....:D
JP
 

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It is actually against the law for a manufacturer to sell a new vehicle in which the speedo reads slower than actual speed, therefore the maufacturers set the speedo to read a little higher to account for variations. I've never had a vehicle that was within 5mph of my GPS. Motorcycles, for the record, are way off, like 15mph @ an indicated 75 in some cases!!
 

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yeah my truck speedo from the factory was always about 2-3mph higher than actual speed
 

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there went my waranty several thousand miles too soon :rant:
 
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