My TRD Sport has stock 18 inch wheels and the temp spare is on a 17 inch rim. The spare is about an inch smaller than the regular tire circumference. Its an odd looking tire with a balloon like sidewall and real shallow tread. I would not want to drive on this spare over 50 MPH or while towing or in bad weather. Don’t get me wrong I love my truck but the spare is a real looser and one of the first things I changed.
A bit more info, the stock tires on stock wheels are 31.5 inches in circumference. They are the same overall with as the spare due to the ballon shape of the spare. The stock tire fits perfectly under the trunk and does not hang any lower than the spare.
So, if I wanted to use the spare steel wheel, I wonder could a 265/70R17 be mounted on it and that would bring it up to the same diameter as the 265/65R18 OEM's? I read that it is bad on the differential to have a smaller diameter tire/wheel running on the axle vs. it's mate on the other side.
I don't know if the 265/70R17 would fit on that rim. It is the right tire size at 17 inches, but if you pull the spare down you will see that it's an odd looking tire and I don't know if that rim was made specifically for a temp type of tire. I found a used stock TRD Sport wheel for $190 on eBay including shipping. It was a take off from a vehicle that the owner switched rims so it was essentially brand new, and I was able to get a Cooper light truck 265/65R18 blem that is nearly identical to the stock tire for $145 mounted and balanced. For not too much money I got a full size spare to identically match the stock wheels and now I have an extra rim if (when) the wife mangles a rim parking.
