What effect Would a donut spare have on a differential?

[mrpj]

Originally Posted by Bluevitz-rs

You need to think outside the box a bit.

Jack up the rear and replace the rear tire with the spare. Then jack up the front and put that good tire on the front. Not too difficult

You are, of course correct. I obviously forgot to put on my thinking cap.
I still don't think there is a more substantial risk by fitting it to the front IF care is taken when driving. Toyota don't offer any preferences or warnings in the manual either. If it was that impotant, they would surely advise rear fitting only?
In the U.K. it is usually avised, when replacing tyres, to fit the new ones on the rear i.e. if changing front tyres, swap the wheels, front to back. So fitting the spacesaver to the rear sort of negates that.
We don't rotate tyres/wheels which seems to be common in the U.S. nor is it part of the sevicing schedule.
I have an old classic car and all the tyres are no wider than the Yaris's "doughnut" with no limit on speed - however the max speed of the car is not much more than 60mph!

[Bluevitz-rs]

Originally Posted by mrpj

You are, of course correct. I obviously forgot to put on my thinking cap.
I still don't think there is a more substantial risk by fitting it to the front IF care is taken when driving. Toyota don't offer any preferences or warnings in the manual either. If it was that impotant, they would surely advise rear fitting only?
In the U.K. it is usually avised, when replacing tyres, to fit the new ones on the rear i.e. if changing front tyres, swap the wheels, front to back. So fitting the spacesaver to the rear sort of negates that.
We don't rotate tyres/wheels which seems to be common in the U.S. nor is it part of the sevicing schedule.
I have an old classic car and all the tyres are no wider than the Yaris's "doughnut" with no limit on speed - however the max speed of the car is not much more than 60mph!

It's more about the fact that the space saver is has the same section width as a front tire on a motorcycle. You can't predict an emergency braking or steering situation, so as to be proactive, you should simply always put the temporary spare tire on the rear.