Ive had my legacy for little over a month now and have noticed that the wrong size tires have been fitted to the rear wheels.

The fronts are running 215/45/17s like they should but i have 205/50/17s on the rear. How badly is the difference in profile going to affect things? The rear tires are high end and nearly new so I dont want to replace them unless im running a serious risk of winding the diff up.

Need some advice.
cheers

 

you have slightly differing widths too................

the wider tyre is lower profile than the narrower one and will end up being similiar sized overall from your description........

 

Different diameter tyres front and rear will kill the center diff.

 

2 new tyres are much cheaper than a replacement centre diff! Plus you can Ebay the nearly new ones to claw some money back.

 

Theoretically 215/45-17 are 625mm diameter and 205/50-17 are 636mm diameter. So 11mm bigger or 1.7%.

I agree in principle that different size front and rear will put extra load on the centre diff but diffs are designed to allow the front and rear to go different speeds, that's why it's there, will less than 2% difference really wear it out?

This is the same difference as having brand new tyres on the rear and half worn tyres on the front. Would you worry about that?

 

This is really my question? Will I be okay to run with the current rears until they need replacing or should I get them done sooner?

 

I know this thread hasn't been used for a weekish but I thought it was important to bring it back seeing as no answer has yet been given.

Change your back tyres to match the front or vise versa. You are causing a lot of strain on your centre diff.

Your back tyres are actually the bigger ones. If they are premium tyres then they are likely to be made to the maximum tolerance, which is about 211mm giving a sidewall size of 105.5mm, this makes the overall rolling circ even bigger. If your front tyres are more of a budget brand then they will be made to the minimum (less rubber used).

Even if they are the same brand you are still looking at your back wheels turning 15 times more per mile than your front.

So with this in mind you could easily have a 2% difference.

Get them changed as quick as you can.

Tony

P.S. I worked as Michelin Trained Tech for a few years at Management level in case you are worried about duff advice from a newbie.

P.P.S. Your centre diff is there to deal with differences caused by cornering not for major tyre differences.

 

What car is it? cuz if you have DCCD you will be fine, AS LONG AS YOU LEAVE THE DIFF OPEN.

 

Legacy ! first line....

LOL

DunxC

P.S. Go back and complain ?