Tires: Tire Size, truck application, rear tires

Question
Can I up my 1997 F-250 light duty extended cab Ford pickup tire size from P255/R70-16 to a P275/R70-16 with my current rim's.
Thanks.


Answer
A P275/70R16 will fit on the stock 7" wheels, but I question whether there is enough load capacity for the vehicle.

I think my book is wrong, but it says your vehicle came with LT235/85R16's inflated to 58 front / 80 rear - which means Ford designed the vehicle to have 3042 # of load capacity in the rear tires.  While this may seem way more than needed, they incorporated some reserve into the calculation in order for there to be additional safey - underutilized tires fail less often.

A P275/70R16 only has 2340 # of load carrying capacity, which is much smaller than what I wrote above.  BTW you have to derate P metric tires 10% when they are used in the Light Truck application.


Hope this helps.