Changing Tyres
 

Got a puncture in my drivers side wheel, so I've replace BOTH the front 2 tyres.

Heard I should of chaged all 4, due to diffs etc etc.

Is this the case?

How much tread on the rear two? If they're half way through their useful life then some would say yes, change them. If there's a 1mm difference in tread depth then some would argue you should be OK. Sorry, I'm no expert, just going on opinions of some who seem more knowledgable on this.

About 1/2 tread on the back...

bttt

Don't suppose the spare one's a F1 215/45/17 is it? In the same boat myself, need one rear for MOT and being frugal don't want to buy two.

Yeah but can you just replace 2 at a time, or do you have to do all 4?

I read on here a few weeks ago that its not a big problem where viscous are fitted, may be different if they're mechanical.

I'm sure the new ones will soon wear and catch up with the fronts!

Chris

Again from a thread a little while ago, I gather it shouldnt be too much of a problem with regard to the diffs - unless, I guess, there is a huge difference in rolling radius front to back - but I think several mm would be ok.

But what may be in issue is the different levels of grip between front and back due to the different tread depths. This shouldnt prove such an issue if you replaced like for like, and all four tyres are still the same brand and model (although even then there can be discrepencies if manufactured at different places). Could still prove interesting in the old handling if there is quite a big difference in tread.

And even if that isnt a problem now, as the ones with less tread get near the end of their life and the newer ones get well bedded in, then I think it will be more noticeable. Of course, if you rarely drive like a loony then this wont be that much of an issues either.

It also means that its likely you will always be out of synch (which is good on the wallet I guess :) ) - although with some nifty tyre rotation you may be able to equal things up a bit after a while.

I think an ideal situation is to replace all four. But financial factors, the fact that there is life in the older of the four tyres, and the fact that I'm not spending any money in this situation :) make that easy for me to say!!

Just my opinions and not necessarily backed up by scientific evidence :) (ie I could be talking balls :D )

John