I need to replace my tires (today) and need some help. I have a 98SC w/ 5.4 and 3.55LS. My current tires are P25570R16. I want to replace them with LT2657516. I need to know which speedo gear I need to get to keep the speedo accurate? If it matters, I have the E40D tranny.

Will there be any problems I have a flat and use the original spare on one side of the rear and the 2657516 on the other? I would potentially have to use it this way for 500 or so miles if I was out of town.

Thanks in advance for the help.

Jim

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1998 F-150 XLT SC 5.4L

 

Jscott,

You are looking at a 5% diffrence in tire size. That means at 60 you will be doing 63
and at 70 you will be doing 73.5.

So I wouldn't worry about the spedo being off. As far as the rear end and diffrent tires, if you have a LS rear end than yes, it could be a problem.

Regards

Sean


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2000 F150 XLT 4x4 Extended Cab

• Deep Wedgewood Blue
• 4.6L Manual Trans
• Ford Tonneau Cover
• Magnum Bug Deflector
• Panther 16x8 wheels with 285/75 R16 BFG All Terrain T/A
• 'Superchips' Performance Chip
• K&N FIPK (With custom mod)
• Westin Side Bars (Black)
• 3" Jardine Cat-Back Exhaust with Crome Tip
• Clear Corners
• Tinted Font Side Windows

 

I have some answers...

I am going to put Michelin LTX AT LT265/7516 tires on. I will need to take my speedo gear to the local Ford dealer (Bankston Ford) along with the distance my speedo is off and at what speed. The parts guy will find the right gear for me.

I was also told that Ford will need to program the PCM in the computer with the new tire size for $75. This is due to the ABS and the tranny shifting. Will this change my computer code? Would I be better off buying a custom SuperChip?

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1998 F-150 XLT SC 5.4L