4WD car, replace two tyres or four?

[horton]

I need to replace the rear tyres on my 1997 Toyota Caldina GTT but I still have the previous tyres, three of which were OK but one was unusuable.

Can I replace the rears with same size, different brand tyres - obviously both the current and previous sets are part worn.

The car has both traction and stability control, automatic gearbox and from what I have read is permanent 4WD (maybe that makes it AWD rather than 4WD)

I've heard different stories from different sources, so I'm a little confused.

Edited by horton on Thursday 19th May 19:29

[EDLT]

Replacing one or two worn tyres will not kill you or the car. Despite what some people on the internet say.

[CanadianScot]

Some cars are pretty sensitive to it, I know mine is twitchy with different tyres front and back.

[rb5230]

I must be being thick, whats a Toyota GTT?

[EDLT]

rb5230 said:

I must be being thick, whats a Toyota GTT?

Some mad jap-import according to his profile.

[Caulkhead]

There are very few 4WD systems that are sufficiently sensitive and fragile to be damaged by having a mix of worn and new tyres. Having said that I always prefer to rotate the tyres on my 4WD car so that i buy 4 at once and all 4 tyres always have a similar depth of tread. I also only like one type of tyre all round but that's more my OCD than an absolute need!

[rb5230]

EDLT said:

rb5230 said:

I must be being thick, whats a Toyota GTT?

Some mad jap-import according to his profile.

Just looked it up, a curious thing.

[LandingSpot]

The (2nd and 3rd Generation) Caldina is basically an Avensis estate, with 3S-GTE 2.0L Turbo unit and permenant 4WD.

http://en.wikipedia.org/wiki/Toyota_Caldina

[horton]

rb5230 said:

Just looked it up, a curious thing.

Sorry, I missed the word Caldina from my initial post.

http://www.autospeed.com/cms/A_2843/article.html

[Hereward]

Don't see a problem so long as the rolling radius (or whatever it's called) of all four tyres is roughly the same. Some vehicles with lockable diffs can get in a pickle and start locking up if a wheel or wheels is rotating faster than the others.

[rb5230]

Replacing 2 tyres will be fine.

[edo]

Personally I like to have matching tyres all round (esp on a 4wd), but not doing so will not cause you to die in a fireball.

[The fatboy]

as least they are on same axle it's fine

[gareth.e]

You could replace one and it would be fine.. two if you want to be more anal and rag the car..

4 is a complete waste unless you need it to be at its 'peak'

[horton]

I'm not overly concerned about the car sliding off the road, I am more concerned about doing some damage to the drivetrain by not matching tyres.

I would match left and right, just the fronts and rears would be different.

Considering the amount of tread on the tyres, it would probably give me another year or so, without having to buy replacements - however this would be a stupid false economy if it ended up damaging my car.

I would just ask my Toyota dealer, however based on past experience they would recommend the most costly option available.

[LandingSpot]

horton said:

I would match left and right, just the fronts and rears would be different.

Considering the amount of tread on the tyres, it would probably give me another year or so, without having to buy replacements - however this would be a stupid false economy if it ended up damaging my car.

As long as you have the same size tyre all round you will be OK. If you had say 215/50R16s on the front and 215/55R16s on the rear, then you will be confuse the centre diff in to thinking as if the rear axle is skidding and wear is not recommended. If the fitter says "You'll be fine mate" cos he has some tyres to shift, slap him!

The difference between same size tyre but fresh vs worn is minimal and is probably equally effected in a similar way with tyre pressures!

[andy43]

EDLT said:

rb5230 said:

I must be being thick, whats a Toyota GTT?

Some mad jap-import according to his profile.

A 200 hp 4wd Corolla estate by the looks of it. Cool.

Needs private hire plates for some real traffic light fun though...

[edo]

horton said:

I am more concerned about doing some damage to the drivetrain by not matching tyres.

The definably wont happen IMHO.

[LandingSpot]

andy43 said:

A 200 hp 4wd Corolla estate by the looks of it. Cool.

Needs private hire plates for some real traffic light fun though...

255bhp in standard form (used with V Power as imports need high octane fuel).
300 is easy with mild tweaking!