Do I Need To Change The Spare To A Larger Size?

I recently put a set of FJ rims with 265 70 17's on my DC. The current spare tire size is 245 75 16. The new tires are larger. Is it necessary up-size the spare to match or is the current spare size ok?

 

With 1" difference - I wouldn't run it. The two wheels will have a different rolling distance and that could create problems in the diff even if its an OPEN diff. Personally, never tried it myself and I wouldn't dare try it (just in case).

Call around to local shops in your area - ask for a USED 265/70/17 tire. Even if they have ones that are 'out of inspection' but have plenty of tread left are good enough to use as a spare and would be much cheaper than buying a new one.

 

I was thinking the same however my stock spare rim is 16"...so how about 265 75 16?

 

that will work . I have same set up as ur , I took 1 wheel off and put spare tire on then measure same level .

 

Using dissimilar rims, even if the tire size makes up for the size difference, will cause handling problems. The smaller rim tire will not sit the same as the others.
It'll probably get you home, but i wouldn't risk it. Match all the rims and tires. Cheaping out can cost you more than you'd like to pay.