Odd tire sizes and all time 4 wheel drive

2000 Ford Explorer. I blew one tire on forrest roads and ruined the tire by running on it too long. Remaining tires have 1/3 tread left. How important is it to get a replacement tire to match the circumfernce of the other three. I had three diffenert Ford dealers with two totally differenet answers. Two said no more that 1/4" diff. in circumference. One said " no worry, that’s what the differential is for". I’ve got the spare on and has never bee used. P235 75R15. old tires have 5-6 MM tread lect, the spare has 13MM tread

The differential is designed for some slip but not continuous which simply overheats the fluid. It may turn into pennywise and pound foolish.

If the vehicle is AWD you risk damaging the transfer case if you have different size tires.

If you have only 1/3 of the tread left on the remaining tires then it’s time to replace all 4.

You need four matching tires. I suggest you buy four new tires. Trying to match three worn tires with a forth is not going to be easy. The dealers who said no more than 1/4" difference in circumference are correct.

Is this vehicle 4wd or awd. If a true 4wd (which I think it is)…it’s not going to hurt anything. AWD is something totally different.

If the vehicle has limited slip differential on the rear placing an odd ball tire there will likely burn that out whether 2wd, 4wd or AWD.

I would read the owner’s manual and make my decision based on Ford the manufacturer’s recommendation. Unfortunately, dealers are not all-knowing and are not necessarily known for reading or memorizing an owner’s manual either, so I would not take their word for it.

The 1/4" circumference suggestion is very close the Subaru’s standard, which appears to be the most stringent. If you are not a gambler, go for four new tires, or three exact replacement tires so you can use the full size spare on the ground.

If the vehicle has limited slip differential on the rear placing an odd ball tire there will likely burn that out whether 2wd, 4wd or AWD.

Agreed…I didn’t think of the Limited slip. I should have…because every SUV I’ve owned has limited slip.

I tried to replace a tire which had a tear in it on a 2002 Subaru, tire dealer would not sell me one tire. Explained how some people had to replace very expensive transfer cases on their vehicles due to the difference in tire sizes. I ended up putting my snow tires back on then trading the vehicle in. i googled transfer cases and tires, found many sites identifying transfer case problems with many manufactures. I questioned the tire dealership about the use of a small spare tire provided with the vehicle, he stated the less distance traveled makes its use worth it.