On a trip to Denmark the rear left tyre got damaged (long rift on the inner edge), and it was really difficult to get a replacement of the 275/45 R21 Pirelli Scorpion Verde tyre. I managed to get hold of a new Continental SportContact 6 in the exact same dimension (275/45-21), but afterwards I’ve found out that the circumference isn’t 100% identical to the 3 remaining Pirelli’s.
Is it OK to drive with 3 Pirelli’s and 1 SportContact 6 in the same dimension, but with slightly different circumference?
Or will this cause excessive wear on the center differential?

whats the difference in tread depths??

can you fit the spare if its roughly the same as the rest of the road tyres..

You should never mix different tyre types on the same axle as each make of tyre has different grip, stopping and breakaway characteristics.

All tyres on the vehicle should be the same size. No arguments, this is a must and you will be breaking the law (in the UK) if you fit a mix of tyre sizes to your car.

I hope that the above clears up your predicament?

Jim

There’s no law against mixing tyres - except cross ply and radial and the former no longer exist really.

I agree that all 4 should be the same and never understand people economising with tyres, but many do for their own reasons.

The spare is of the original 255/50R20 size, and due to that this is 2.3% less in diameter than the 275/45R21, I haven’t used this spare lately.
The tyre diameter difference between the Pirelli and the SportContact is around 0.8%; the SportContact is 768 mm in diameter, and the rear Pirelli is around 762mm, even if the thread depth on the new Conti is 1mm less than the 2 year old rear Verde (4mm vs 5mm)..

Just to be clear: all tyres are of the same dimensions: 275/45R21, but still the circumstance is slightly different. And yes, I agree that ideally all tyres should be of the identical brand and size, but I would hope to avoid to replace all 4 tyres due to this...

Will the 0.8% difference in circumstance on the rear tyres cause wear on the center diff?

Last edited by Eirik34 on 13th Jun 2019 6:46pm. Edited 4 times in total

jim4244 wrote:

All tyres on the vehicle should be the same size. No arguments, this is a must......



Jim

The rear diff will of course handle a difference in diameter between the two rear tyres, but the question is if the 0.8% difference in circumstance on the rear tyres will cause wear on the center diff? The local workshop claimed that all permanent 4x4 cars need to have the exact same tyre circumstance on both axles to avoid wear or breakage of the center diff. Is this the case for L322 as well?

ownerinfo.landrover.co.uk (the online source for manuals, one can choose Norway too) for the 2017 model year says that tyres should ideally be replaced in sets of four, and if that is not possible then two the same on each axle. The choices available in the UK on that site seem the more recent models, you may of course be able to consult a hard copy manual for your own car.

My understanding is that the more modern cars are a bit more tolerant of minor differences than would have been the case with older technology, but as others have observed it is not ideal. If I were you I'd either get another Conti for the other side of that axle or, if your Pirellis are not much worn, another Pirelli to make a matched set and then when you come to replace the Pirellis buy three Contis and use the one currently on the car (assuming you find their characteristics acceptable).

I would be wary of running your smaller spare wheel for any length of time alongside the 21" wheels/tyyres, just at low speed to the repair shop. Only Range Rovers since 1988