Guys, I just went up to a 265/75/16 from a 235/70/16 tire, and I dont know if its me but I think I notice a little slower response from the engine and a little lack of power.

Can this be true?

(oh.. I have a 01 4.6L XLT )

-Chris

 

Yep, anytime you increase the diameter of your tire, you effectively lower your axle ratio.

You can check the diameter and Revs per mile here

 

Do you have an automatic or a manual?

If it's and auto, the tranny is self learning and the shift points may now be off for the difference in tire size. To reset the tranny, undo the neg. side of the battery, turn on the lights momentarily to drain the system, and wait ten minutes. Re-attach the battery and you will be back to factory defaults. It will take up to 500 miles for it to re-learn and adjust.

That's a huge jump of almost 10%. So a felt power loss of 10% would be normal. You'll probably have to live with it or go smaller.

 

anyway to get it back????? The power that is,, NOT the old tire size..

-Chris

 

Change gears or performance upgrades....turbo, super charger, etc.

 

Don't forget, unless you corrected your speedometer, it is now reading about 9% to 10% low.


SM
'01 Screw
4.6 4x2

 

a good custom tune would help in your power loss and help recalibrate your speedo.

 

The best way is to re-gear. A tune will help, but it won't get everything back.

 

AN exhaust will also make up for the last power, the stock y pipe in these trucks are very restrictive, so I suggest cut out the y and run dual exhaust with a crossover

 

Regearing is your best option.