I have a fried that recently changed his 06 f-150 4x4 xlt stock 17 inch wheels over to factory FX2 18 inch wheels. They fit fine, stock size tires. My question is about his spare. Its still the stock 17 inch, with a smaller tire size. If he was to get a flat, is it possible to use the 17 inch spare? and if so, will it cause any damage being that it will be a smaller wheel and tire. Thanks.

 

If he gets a flat in any of the front two tires I don't think it will be an issue as slong as he takes it nice and easy and drives directly to the tire shop. If any of the rear two get a flat than yes that will effect it significantly. It'll effect the differential specifically. His best bet if he were to get a rear flat would be to switch a good front tire to the rear and place the spare on the front. Or just buy a used 18" rim and a used tire. Who cares what it looks like, its only going to be on until you fix the flat one.

 

The overall tire diameter is what will make the biggest difference. What are the two tire sizes? If he has a LSD then I would be slightly concerned if the tires' outside diameter was different.

 

i have a spare off of a 06 fx4 it is a 18" rim not sure of the tire size send me a message if you want it

 

Thanks for your help. Ill call him tonight and ask the size.

 

His tire size is 265-60-18. The old size was 255-70-17 if that helps.