Smaller Tire Size Specs

[shwagy357]

I have a 2002 GMC Sierra 1500 w/ P245/75R16 tires installed. However, the info in the door jam only refers to P65 tires. I have found that my speedometer is off, relevant to my GPS. I believe this is due to the difference in tire size. How can I fix my speedometer to display my correct speed?

 

Also, does anyone know how much air pressure is recommended for the P245 tires? Or could someone please point me in the right direction to figure this out?

 

 

Thanks

[griffy2]

Hi if there passenger tires load range C max. 50 lbs. Id usually run about 40 lbs.

[AThomas7782]

Hi if there passenger tires load range C max. 50 lbs. Id usually run about 40 lbs.

Sounds like he has P metric tires, which will have a lower maximum. Run them at 35 PSI unless towing. Max will probably be 44 PSI.

[stlavsa]

Hi if there passenger tires load range C max. 50 lbs. Id usually run about 40 lbs.

Sounds like he has P metric tires, which will have a lower maximum. Run them at 35 PSI unless towing. Max will probably be 44 PSI.

 

 

How far off is the speedo? couple mph fast? If u stepped up to a 265 it will probably correct it, or get the ECM recalibrated