Can I run 275 45 R20's on the rear and 275 40 R20 on the front? I guess not as it will screw up something.

Currently have 275 40 R20 all round but would like to change to 45 profile for a bit more comfort. However front only went on 8000 miles ago so still have quite a bit of life in them. Robin
2008 Range Rover Sport TDV8
Gone:
Jaguar S-Type V8 4.2 Sport
MGZTT 190 2.5

Not recommended mate 2003 BMW M5 - 5 Litres of V8 Optimax Slurping Goodness in Carbon Black

2013 SDV6 HSE Black Edition- Orkney Grey with Ebony & Ivory. LR Facelift RAI, Genuine G4 Expedition Rack, 4x Warn SBD-160 Spotlights, Warn 9.5XPS Winch, Mantec Underbody Protection and Sump Guard, Full Easy Lift Suspension Module, LR Light Guards, Light Force HTX230 Hybrid spotlights, 18” Compomotive PD1881 on 265/65/18 BF Goodrich KO2, ARB fridge, TuffTrek awning 😎

Cheers Buckster. I thought as much but worth asking  Robin
2008 Range Rover Sport TDV8
Gone:
Jaguar S-Type V8 4.2 Sport
MGZTT 190 2.5

You`d be increasing the diameter of only 2 wheels then.

It`ll look something like this


 Steve.

Agreed, would advise against mixing profiles.

Cymruambyth wrote:

You`d be increasing the diameter of only 2 wheels then.

It`ll look something like this

 Robin
2008 Range Rover Sport TDV8
Gone:
Jaguar S-Type V8 4.2 Sport
MGZTT 190 2.5

 2016 RRS SVR Estoril Blue
2005 4.2L Supercharged Java Black - gone but was my first love.
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If we all point our RR's in the same direction and accelerate at the same time can we turn back time?

http://www.rrsport.co.uk/forum/topic35871.html

Mixed wheel sizes cause headaches

Put a decent pair of part worn tyres on to match the others Robin

Then change all four next time for the other size your after  Porsche Cayenne 2022
gone Porsche Cayenne 2020
gone Corris Grey HSE Dynamic 2016
gone Ipanema HSE lux 2010
gone Rimini HSE 2005
!!

Now there’s a thought.  Robin
2008 Range Rover Sport TDV8
Gone:
Jaguar S-Type V8 4.2 Sport
MGZTT 190 2.5

Yes, you can. A lot of BMW's have wider wheels on the back, and therefore have a different profile. Eg, you would have say a 305/45 on the rear. You would need to work out exactly which on a calculator. The 40 just means 40% of the width. 2012 RRS SDV6
2014 BMW 320d X-Drive Touring
1999 VW Polo stage rally car

Yes, you can. A lot of BMW's have wider wheels on the back, and therefore have a different profile. Eg, you would have say a 305/45 on the rear. You would need to work out exactly which on a calculator. The 40 just means 40% of the width.

If my calculations are correct, if you run a 275/40 x 20 tyre on the front you would need to run a 245/45 x 20 on the rear to get almost the same rolling radius. 275/40 x 20 is 228.71cm a 245/45 x 20 is 228.87cm not sure I would want to put a 245 tyre on a 9.5J rim. and run it on a 2.5 ton Sport. Also kind of defeats what Robin is trying to achieve surely.

Cheers
Col

Agreed, no-one suggested putting a 245 on a 9.5j rim from what I can see. I just said it can be done. 2012 RRS SDV6
2014 BMW 320d X-Drive Touring
1999 VW Polo stage rally car

RallyXS wrote:

Yes, you can. A lot of BMW's have wider wheels on the back, and therefore have a different profile. Eg, you would have say a 305/45 on the rear. You would need to work out exactly which on a calculator. The 40 just means 40% of the width.

RallyXS wrote:

Yes, you can. A lot of BMW's have wider wheels on the back, and therefore have a different profile. Eg, you would have say a 305/45 on the rear. You would need to work out exactly which on a calculator. The 40 just means 40% of the width.