Mixing 'old' with 'new' tyres?

[Damned67]

Hi All,
I've recently (Nov. last year) picked up a nice cheap '98 Outback. It's got an alignment issue, and one of the front tyres is wasted. This actually comes at a reasonable time, as I just got a little 'bonus' money, and having just separated from the wife, any money is an exciting prospect!!!.

Here's the deal. Tyres are 205/70R15. The car has one shot BFG Longtrail T/A tyre, two fairly good Longtrail T/As (about 3-3.5mm tread depth), and a GoodYear Wrangler (?).
Obviously, the toasted Longtrail and the Wrangler need to go.
Question is, can I settle with two new Longtrails and mix them with the old Longtrails. I remember hearing many years ago that 4wd tyres needed to be replaced as sets of 4, as a pair with significantly lower tread depth would also have a shorter rolling circumference, and then place undue wear on the transfer case.
Is that still considered the case, more of an issue for much larger 'truck' tyres, or complete bollocks all together?

Basically, if I can get away with two replacement tyres, then I can also afford to get replacement CVs (as preventative maintenance, as they're the originals and the car has well over 300k on the clock).. which is what I'd prefer to do. But would also prefer to pay an extra $400 for 2 more tyres, as opposed to buying a new transfer case!

If I need to replace all 4 tyres, is there a reasonably priced tyre people would recommend for someone doing 99.5% On road (and about 40,000 highway km's per year), and 0.5% Off road (which has only ever been a few kms of dirt road with the boat hooked to the back)....?

Cheers in advance!

[robothefisho]

My understanding its permanent awd? so it has a centre diff? I'm going to assume that none of them are limited slip diffs, in which case put whatever you want on there. But i would be inclined to put the 2 new tyres on the front. or atleast same axle. The replace all four at once is good practise, but on 4wds which are a 50/50 locked drive and lsd it isnt good to have different tyres as somthing has to give. But doesnt really matter cause 4wd would normally be engaged in low traction areas.

[darylive]

As long as the tyres are the same size it doesn't really matter mate. Wear on that vehicle doesn't matter a zot as long as they are all good. Chunky v bald on a big 4x4 is not a good idea but you haven't got a problem. Just be sure the tyres are the same size.

Get two new ones if that's what you can afford. Put them on the front and the two good old ones on the back. There is no sense replacing the other two if they are still good.

A/T i.e. All Terrain are the go for a good all rounder. Different brands, different prices, most ATs are good now days no need to spend a fortune. You just want something with a bit of tread if you go onto the dirt. Duellers are good and popular. A chunky off roader is not what you want the noise will drive you made on the road and you won't get wear from them.

[Damned67]

That's my understanding, permanent 4wd with a centre diff.
I asked the same question on a Subaru forum, and the one person that answered said: "... I can tell you now, Subaru with centre diff/AWD system, its not recommended to have 4 different size or 2 different size tyres, even if its 0.05% out you will wear out the centre diff over the time (like my previous Liberty did (wore centre diff out)". But he also went on to say that his car "... had 215/50 16s front and 205/55 16s rear", which is a big difference to the same tyres with different amount of tread.
I'm happy to replace all 4 if needed, but that extra cost of two tyres could buy me an overhead fishing outfit!
Cheers!

[finga]

I know what I'd be doing if I was in your boat.
2 new ones for the front. Old ones to the rear.

But if it was a choice between fishing gear and tyres I'd be picking tyres because a few mm on the good ones won't take long to go especially if the allignment was crook. The difference may not be obvious now but when they get done a smidge more the shoulders will be crook.

[lethal098]

should not be done

[Damned67]

Thanks Lee,
Appreciate the opinion. Simply based on the fact that I have the money to do it right now, I'm replacing all four.
Cheers!

[Chimo]

Did you do any good with monaco?

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