Mike Burton

Not sure if this should be in technical... but here goes.

Rang the lease company before Christmas to say the car was tram lining all over and I wanted to replace the front tyres. "fine" they said, just contact your nearest ATS.

So I rang my ATS branch, explained I wanted two new front tyres. Told them what lease company it was etc. etc. They came back with a list of 4 tyre manufacturers, and the lease company told them which ones to order. (Michelin)

Anyway, Saturday morning, I take my car into the local ATS branch leave them the car and go for a walk into town while they fit my nice new front tyres.

I got back to the branch and hour or so later, new tyres are fitted to the wheels, but not on the car. Their is some kind of discussion going on in the office.

The lease company rang back to say they couldn't fit different make of tyre to the front of the car, as they hadn't realised it was 4x4, and it would ruin the diff. Now I've heard some guff in my time, but that was a new one on me. Like running a set of part worns on the back and brand new on the front is any different?

Anyway, after much telephone shouting type stuff, they said ATS had to put my old tyres back on. Problem with that is that Im going to Southampton (700m round trip), and one of the fronts is on the dodgy side of legal. Lease company still says that the new tyres now have to be Bridgestone, so they match the back. Said they would locate some and get them to the branch (which shuts at 4). Of course they failed to find some, but ATS branch manager found a pair of Bridgestones at the York branh, so he went to fetch them. (60m round trip) !!!!

What makes this whole thing a joke is that although I've got OEM Bridgestones on the rear, I've now got a pair of brandspanking new S02's on the front. Same make maybe, but that would appear to be all they have in common.

What a joke.

Thanks go to ATS for sorting it out !!!!!

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Mike

Lambo

ATS were talking a load of rubbish regarding different tyres affecting the drive train, the only thing that would do that is using tyres with a vastly different rolling radius.
They did have a good point about using different types of tyre though. Each tyre type has different performance characteristics and using different types can effect the handling of the car so I would always stick to the same tread patteren all round amd this is especially important on a 4wd car.
Next time swop the front and rear tyres so they wear down at the same rate then you can swop all four at the same time...

Pete Croney

Mike

I would be VERY careful.

Once bedded in, the SO2s on the front will offer much more grip than the worn RE010s on the back.

I would put the good tyres on the back, or you could be swapping ends very easily.

Mike Burton

It was the lease company that said I couldn't run different profile tyres on the front and back, NOT ATS.



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Mike

ian_sadler

With my old Audi 90 Quattro it said in the manual not to run a mix of tyres 'cos the 4x4 system had nylon gears an if the wheels ran at slightly different speed then it would dammage the diff.

Anyway, I'd hate to mix different make or model tyres anyway.

Just my 2p.

Ian

Nick L

I have a company Scoob and have this problem every time I need to change the tyres. The Fleet Management department can never get their story straight - Apparently a letter from Subaru recommends Bridgestone while the company policy is Michelin. What really messes it up is that I was forced to get Dunlop SP9000 Sports a while back due to limited stock in the area(I left it a bit late to change and lets just say they were great in the dry but a little slippy in the wet).
The next problem you are likely to have is that the SO2's are discontinued now, so getting hold of them could be difficult - When I got two new boots for mine at xmas I was told they rarely get more than 10k max out of SO2's.

Mike Burton

<Quote:> With my old Audi 90 Quattro it said in the manual not to run a mix of tyres 'cos the 4x4 system had nylon gears an if the wheels ran at slightly different speed then it would dammage the diff.
</Quote:>

Which goes back to my comment about having part worns on the back and brand new ones on the front. Complete crap IMHO. Anyway, ain't the whole point of a DIFF to handle stuff like "slightly different speed"?

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Mike

Josh L

It has been mentioned before that running tyres with vastly different amounts of tread can cause diff problems, but I thought it referred mainly to when used across the same axle.

We need a considered reply from someone like PC here methinks.

Josh

RichB

I had the same setup, New SO2s on the front half worn RE10s at the back, brown trousers in the middle!
Went back and bought 2 new SO2s after nearly losing it at 30mph round a roundabout in the wet. Scary

Mike Burton

BTW: Im not saying its exactly a good idea to run different tyres on the front and back for grip/predictability reasons, but I do have *issues* with ppl (i.e lease company) saying it will damage the car's diff's etc.

Might swap them front to back after reading the replies to this

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Mike

Jolly Green Monster 2

I think the diff should handle it, just that if you run it for long and the diff fails then Subaru can point the finger at the tyres which could in rare cases be effected by the different tyre sizes, tread patterns.. different patterns will grip / slip differently etc... but if it were really that bad don't get a puncture as the space saver is a totally different ball park from the alloys...
I think the lease company were trying to follow their guidelines and two bridgestones and two bridgestones should be better than two bridgestones and two michelins but they obviously know nothing about so2's etc.... at least they tried... you'd soon be moaning if the diff failed....

The more important issue is the differing grip given by different tyre rahter than damage to the diff...

I have run different tyre makes on bikes before and some are compatible and are fine.. but others tranform the vehicle into a death trap... depends on you driving style of course...

As it is a lease car I'd swap the tyres around so the older ones are on the front and therefore wear quicker and then swap them for the same as the backs.. the problem of S02's fazing out is another problem.. just watch for understeer....

When I bought my current Scooby it had three part worn and one brand new tyre on it... ran like this for 10,000miles without hitch... now swapped to four the same... for piece of mind though.

Just my opinion.

ho ho JGM