Tires: Tires, ford f 150, max load

Question
Can I use 225/75R15 tires instead of P235/75R15 tires that are currently on my 1994 ford f 150 4x4 pickup?

Answer
Dear Mr. Williams,
Thank you for using AllExperts.
My data shows that your pickup truck came with P235/75R15 Extra Load tires from the factory.  Each tire would have a max. load capacity of 2,183 lbs. at a max. air pressure of 41 psi.  This what your vehicle requires.  The (P)225/75R15 tires in a "standard load" only carry 1,874 lbs. per tire at 35 psi.  That's a HUGE difference, and I CANNOT recommend that you do this for safety reasons as the 225s may fail in service.  
DT