Spare size

Alright guys, going on vacation from Louisiana to Florida in a couple weeks, and was gonna buy my 33s before I went just to have the truck looking right but it just hit me, spare tire isn't 33 inches, and don't really want to buy 5 new tires and wheels right now, so my question is I run 265/70r16 right now, spare is 245/75r16. Almost no difference in height just a little difference in width, so as far as my trip is concerned if I just roll on my 265 and get my 285 when I get back, if I do have a blow out the slight difference in tire size should not hurt anything for running at interstate speeds right? Any insight is appreciated.

 

Going around turns one wheel go’s through a larger arc. That’s why there is a differential on drive wheels; this allows the outer drive wheel to rotate faster than the inner drive wheel. The issue with AWD vehicles and mismatching the wheel size is, when driving in straight lines one wheel will always be dragged. Really what happens is the AWD differential mechanism is always engaged and burns out prematurely. Note I’m simplifying things for brevity.

If you are in 4 Wheel Drive with different wheel sizes you have the same issue. YMMV

 

If you need to use the spare just don't run the truck on pavement in 4WD. I ran a smaller spare for 5 years, used it a few times and never thought twice about it.

 

Your spare has the same overall height (diameter) as you stated, so it is not an issue running it in an emergency. There might be a small difference is the tread depth is not the same (new verses worn).

You haven't described what you are driving. I assume you have a Tacoma pickup (which is NOT an AWD vehicle). If there is a slight difference in diameter, it would cause issues in the rear if you have a locker or LSD. If you are open, then the spiders will be spinning a bit while going straight. Not a big issue IMO. No issues at all in the front.