Blogs Car Info Our Show Deals Mechanics Files Vehicle Donation

Spare Tire Size Discrepancy Lincoln LS V8 Sport Package

The recommended tire size for my Lincoln LS 2001 V8 Sport Package is P235/50R17. Tire size recommended for the V8 without the sport package is P215/60R16. My full size spare tire that came with the vehicle new (eons ago) is P215/60R16. I have the 17 inch rims on the car. Is this a problem? Do I need to replace the spare?

The circumference of your regular tire is 82.46 inches (or less as the tire wears). The circumference of your spare tire is 82.15 inches. I assume this is close enough not to cause a problem.

No, you don’t have to replace the spare. Your spare is the same diameter as the 235/50/17 tire and wheel. In the aftermarket wheel world they call this a “Plus 1” tire and wheel package. The original rim is 16 inches but the tire is a 60 series model. That means the distance from the rim to the tread is 60% of the “215” millimeter width. Multiply that times two and convert to inches (divide by 25.4) and add to the rim diameter and you get the tires total height. The 235/50 is a 50 series, or 50% of 235 mm. That number is smaller so when the additional inch of rim diameter is added in, the total tire height is pretty much the same. Treat it like a temporary spare. The tread is narrower, like those mini spares they use in a lot of cars, so it should be used to get you to a tire repair place to get the 17 incher fixed. It makes a perfect spare, keep it unless you want to do a five-wheel rotation.