QuestionI recently purchased a Toyota Tundra Access Cab truck. The tire size is P245/70R16. My question is: When these wear out should I use larger size tires (Toyota offers P265/70R16 and P265/65R17 for this model)? What will happen to handling and fuel consumption as size increases?
AnswerMark,
As with all things, there are compromises.
I may be stating the obvious, but the P265/65R17 is going to require new wheels.
In both cases, these are larger diameter tires and unless you change the rear axle ratio, your speedometer and odometer will read low by about 4%. Put another way, your speedo will say 60, but you'll actually be going 62 1/2.
Ordinarily when you go up in tire size you can reduce the inflation pressure and gain some ride. But Toyota already says to use what I consider the minimum - 26 psi. IMHO, anything lower than that puts you at added risk of the beads unseating during extreme handling situation - just when you don't need it.
What would also happen is that your fuel economy might be slightly better, because you are effectively changing the final drive ratio. But then again the acceleration won't be as good and you might compensate by pushing harder on the accelerator and completely wipe out the potential gain.
Your handling will probably get a bit better.
Hope this helps.
