Mixed tyre sizes - can I drive it?

[Aussie Jeepster]

I need to replace 2 rear tyres on my D3 this week - 2 punctures which are not repairable.
I currently have 255/60/R18's fitted (previous owner, not my choice) and I'm going to 265/60/R18.
Would it be OK to drive with the 265's on the back for a couple of weeks while the budget sorts out 2 new tyres on the front???? The diameter is 1/2" larger with the new rubber - is that going to be ok, or do I ground the car until I get all 4 done?
Alan

[letherm]

I need to replace 2 rear tyres on my D3 this week - 2 punctures which are not repairable.
I currently have 255/60/R18's fitted (previous owner, not my choice) and I'm going to 265/60/R18.
Would it be OK to drive with the 265's on the back for a couple of weeks while the budget sorts out 2 new tyres on the front???? The diameter is 1/2" larger with the new rubber - is that going to be ok, or do I ground the car until I get all 4 done?
Alan
Hi Alan.

The 265 is wider not higher. The 60 is the profile of the tyre from rim to tread so it should be ok.

Martin

[PhilipA]

It's still bigger.
I was speaking to a relative recently who has a D4. His spare was smaller than the other tyres and it upset the ABS , being fitted on the back.
He had to drive slowly and stop often and turn off and restart.
However this may not happen front to rear.

Regards Philip A

[Aussie Jeepster]

Hi Alan.

The 265 is wider not higher. The 60 is the profile of the tyre from rim to tread so it should be ok.

Martin
Great.
My tyre size guide said it was 1/2" more in diameter. It does also say .4" wider which does not really worry me.
al

[BradC]

Hi Alan.
The 60 is the profile of the tyre from rim to tread so it should be ok.

Err. Really?
I've always taken it as the "Aspect Ratio". It's the width to height ratio of the sidewall, so a wider tyre on the same rim with the same aspect ratio would be taller (have a larger circumference).

I'm happy to be corrected, but every tyre size calculator I've ever used seems to agree with me. You want wider on the same rim, you need to go for a smaller aspect ratio to keep the diameter the same.

Your calculator is correct. One set will be about 1.5% bigger than the other. I wouldn't do it.

[ramblingboy42]

wrong information about aspect ratio.

if you don't know something don't say anything.

giving people incorrect information is wrong and it can damage their vehicle if they heed your advice.

the aspect ratio is a percentage of the tyre width measured on the tyrewall. vis 265/60 x18...the tyrewall height is 159 mm...on a 255/60x18 the tyrewall height is 153mm ....the rolling radius of the 2 tyres are significantly different and depending on the vehicle can produce transmission windup, which can damage your driveshafts/universals/axle splines and differentials

[Ean Austral]

Both tyres are being put on the same axle . ie rear .. why would it upset the car ?

Cheers Ean

[letherm]

Abject apologies for wrong information. I genuinely thought what I said was correct. Thanks for correcting me. I never mind being told when I'm wrong.[thumbsupbig] Sorry for misleading you Alan.

Martin

[DiscoJeffster]

If you had a viscous lsd in the centre differential then front to rear would cause trouble. I did this once on my AWD turbo by simply having new on the rear and old on the front. The centre diff banged its head off trying to jump out the car as it locked up and unlocked thinking one set of wheels were spinning.
In the LR though, the centre is open so it’s less of an issue. As has been said the abs will struggle with it until it learns the difference, and in some cases I’d expect the difference will be outside tolerances and will cause error.

[Turtle60]

For the above reasons no you can’t. But while your at it perhaps 265 65 18. Fits well, no rubbing and bigger side wall if your planning of road trips. Your lucky if you have 18” tim’s. You are spoilt for choice.

[Turtle60]

Oh and your speedo will be spot on too.

[LRD414]

..... But while your at it perhaps 265 65 18. Fits well, no rubbing and bigger side wall ......
This is not accurate. There is some minor rubbing in certain positions depending on tyre fitted for the 265/65/18.
Also, the spare does not fit in the normal location without being fully deflated.
These are issues that many people are happy to live with but the uninitiated should be aware of all factors when increasing overall diameter.

Regards,
Scott

[Aussie Jeepster]

It's all good - I just got a ripper deal on a set of Pirelli ATR+ in 255/60/18 so no issues with mixed tyre sizes.

[DirtDigger]

I have 1only Bridgestone dueller 265x60xR18 2nd hand half thread - good enough for spare, free to good home. I'm in Greensborough, Melbourne if anyone wants to pick it up. I'm chucking it out if no one wants if. Also to 2x Pirelli Scorpion but they are 20" - as OE on previous D4 HSE - also going out of here . Neither will fit my D5. If anyone interested then call me 0488117763

DirtDigger

[DirtDigger]

This is not accurate. There is some minor rubbing in certain positions depending on tyre fitted for the 265/65/18.
Also, the spare does not fit in the normal location without being fully deflated.
These are issues that many people are happy to live with but the uninitiated should be aware of all factors when increasing overall diameter.

Regards,
Scott

I had 265x60 R18 - better size. With BFG AT's they still rubbed on full lock but still able to stow the 5th properly . Gordon at GOE warned of the issues with 265x65R18 - same as what Scott was saying.
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