Will it work, or should I just take it out and lose some extra weight????

 

If you sized your 18s properly, the 18" wheel/tire should have roughly the same overall diameter as your stock 16", which means that the spare tire SHOULD work. It'll look pretty funny, but I wouldn't take it out.

 

The rim size has nothing to do with it. Assuming the diameter of your tires on 18" rims is close to the same as the old tires on 16" rims and you didn't install different hubs, the spare will behave exactly the same way it did before the change.

I've had my spare on twice so far and it's not a pleasant experience. Still, it's better than loading the car onto a wrecker.

 

It's actually a little more complex.

The spare is smaller in diameter than OEM wheels and should not be mounted on the rear. In case of a rear flat, a front tire is replaced by the spare, and the front is moved to the rear. What's important here is to keep the same rolling diameter on either side in the rear. This minimizes stress to the Torsen limited slip differential. So if you've gone to oversize rims and tires, the spare can still be used properly if you have maintained the same rolling diameter with your fronts and rears. In other words, the rolling diameter of the aftermarket wheels can be larger or smaller than OEM, but only if the front an rear wheels are close to the same diameter. HTH

 

Sorry. I thought everybody already knew about the spare only going on the front.

Nothing like being stopped alongside a busy freeway and having to jack up the car twice, take two wheels off and put on two wheels. Hopefully I'll never get to experience that again.