I have a 2005 Trailblazer 4x4 4DR. Original tires are 245/55x17. I have a set of 265/75x17 tires to put on the stock rims. Tire store and dealership said they will not do it because of going up 2 sizes and will be 2 inches higher. Dealership said it will cause problems with the speedo, I said if that is all recalibrate it. Any thoughts? Will they fit without problems?

 

yes it will affect the speedo but i dont think it would much i have 31s and my speedo is off slightly

i think you shouldn't have problems putting that size
this can give you more information on fitting bigger tires
https://blazerforum.com/forum/tech-a...n-i-fit-41671/

 

Thanks. I checked that thread and they were discussing an S10. I have the Trailblazer which is even large so I do not think it will effect it.
Tire dealers and dealership just do not want to mount the tires onto the wheels because of going up 2 sizes. No go reason why except the speedo.

 

The biggest problem with getting bigger tires on the Trailblazer/Envoy is the upper ball joint which hangs over the wheel. Check out this thread over at Trailvoy.com which gives a pretty comprehensive fitment rundown. Good luck.

 

I went from stock 205/75/15 tires on my 98 4wd to 265/75/15 and there is no rubbing and they look great. The speedo is off by about 4-5 mph which I don't care about. However what I have noticed is that I don't have the "get up and go" it did before. I knew there would be some change but I didnt expect such a big difference. Will a PCM reprogram get it back to the "zip" it had before? Or will a HyperTech work as well? If so what do I set the new shift points and gear ratios to?

 

The gear ratio is set by the physical gears in the differentials, and a programmer will only adjust the computer programming to match what's in your truck if you change gears (Ie. 3.42 gears to 3.73 etc). The loss of power is due to the reduced torque with the larger tires (Over simplified definition: torque is rotational force). The only way go really get the zip back is by increasing the power of the truck or changing the gears to a lower ratio in the differentials.

 

Thanks so much. I get what you're saying. I need to change my gears. Do you recommend just changing the differentials as opposed to changing the gears?

 

What's the biggest tire that can go on a jimmy with out lift or body

 

Search its been covered many times