I'd replace all 4 on a vehicle with 4WD. I've not had the choice on any of my cars over the last 15 years as they have all had staggered set ups, but I don't wait until they are low on tread as it isn't worth it. I do mainly motorway and dual carriageway driving so the wear rate is relatively low, so even when they are £300 a piece it's not a huge amount per mile. It was more when my wife had a Boxster and the most we got out a set of rears was 10k miles, but they had a very sticky compound. MY23 Panamera E-Hybrid
MY19 SDV8 Autobiography - Sold

Last edited by Martin2 on 10th Aug 2021 5:43pm. Edited 1 time in total

Treebor99 wrote:

Funny no one has mentioned the extra wear on the center diff?

The centre diff is an open diff, same as the front and rear diffs, it doesn't mind different speeds front to rear, it won't wear it out any more...

During off road driving, it, and some rear diffs, have the ability to distribute the drive to where it is needed but this doesn't wear the diff.

The earlier Range Rovers with diffs that you could "lock" are a different matter...

 Pete

__________________________________________________
2014 L405 Autobiography SDV8 4.4 Loire Blue Ebony interior
2011 L322 Vogue SE 4.4 TDV8 Baltic Blue. Parchment over Navy Interior. Sold
2012 L322 Autobiography 5.0 Supercharged Ipanema Sand, Jet Interior. Sold
2002 L322 Vogue 4.4 V8 Epson Green, Ivory over Aspen Interior (Fatty Offroader) Sold
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“I'm with Stan, much prefer the extra tread at the front especially in the wet when the extra tread depth will help stop the vehicle quicker than having more tread at the rear....

Just my 2p..”

Your 2p goes against the advice of all tyre manufacturers and road safety organisations.

I'm with haylands, I prefer the new ones on the front where under heavy braking, most of the weight will be transferred.

Also, ignoring the fact we are talking about fat and heavy RRs here, I used to do a fair bit of drifting back in the day (all on track). So if we're talking oversteer, as long as I've got enough traction at the front, I can put the the car where I want it with the right balance of throttle, steering and brakes. In the early days, to reduce costs I'd put a new set of tyres on the front and then take numerous pairs of partworns for the rears.

As for the blowout argument, also with the others on the fact that it can happen to any tyre on either axle so not sure I'd base placement on that. Sure it probably is better if it happens, that it's on the rear but in my many years and miles of driving, it's only ever once happened to me, that said it was pretty scary, mostly just the shock of it happening at 70mph but I didn't feel like I was about to lose control and die (admittedly I wasn't driving almost 3 tonnes of box on wheels at the time though).

There is no argument, it is a proven fact that if you are replacing just a pair of tyres it is safer to fit them on the rear axle.

Rotation and replacement of all four tyres at once is the recommended ideal, but in practice few people follow this advice, myself included. Mainly due to, in normal times, clocking up c25k miles pa much of which are on motorways. I change my tyres when the tread gets to approx. 4mm, but always by 3.5mm. The fronts have always worn a bit quicker than the rears. So typical, I’ll swap the rears to the front, fit new tyres on the rear and then get a bit more wear out of them before repeating the exercise in a few months time.

Links to the benefits of rotating and why new tyres in the rear:

https://www.uniroyal-tyres.com/car/tyre-gu...nt-or-rear

https://www.goodyear.eu/en_gb/consumer/lea...tires.html

https://www.tyresafe.org/tyre-faqs/

There are numerous such articles on the web.

Thanks all, stirred up a bit of ‘healthy’ debate too

Like I said, am only doing 1k-2k miles a year so hopefully won’t need to replace 2, or 4 anytime soon. Handy to know though..

Had all wheels off in last couple of weeks to adjust handbrake and Hammerite the front brake pipes (MOT advisory) but didn’t rotate the wheels, so will have a swap around this weekend

[quote=] "LT"Your 2p goes against the advice of all tyre manufacturers and road safety organisations. [/quote]

Hey, I'm just a rebel, it's how I hang....  Pete

__________________________________________________
2014 L405 Autobiography SDV8 4.4 Loire Blue Ebony interior
2011 L322 Vogue SE 4.4 TDV8 Baltic Blue. Parchment over Navy Interior. Sold
2012 L322 Autobiography 5.0 Supercharged Ipanema Sand, Jet Interior. Sold
2002 L322 Vogue 4.4 V8 Epson Green, Ivory over Aspen Interior (Fatty Offroader) Sold
-Click for Project Fatty off roader-

^

I run several RR's and look after MANY MANY more... I always rotate mine every service point... Then I replace either all four tyres or sell the wheels with 1/3rd tyre tread (on eBay or alike) and replace them with a set of premium tyre'd new take off's... Happy days

If any of you have ever tried riding a motorbike with a pair of brand new tyres you'd understand why New tyres should always be fitted to the rear. pretty scary. low grip = low stability / control = bruises and scratches.
New tyres are covered in the silicon spray used to assist removing the tyres from the mould.
New tyres have relatively low grip gradually improving over the first 100 or so miles and can take up to 500 miles.

If I buy a pair I want the already broken in grippy tyres at the front so I can stop! Obvs, when I have 4 new tyres - I'm very carefull! A good tyre fitter will tell you to take it easy until the tyres are broken in.
Once broken in it's perfectly ok to swap them around

As for diffs, I do know they are open, but different sized tyres cause more relative work in the diff cos you're needlessly spinning the diff gears faster than you would need to if all tyres were even, ergo my question about more friction and wear.
I still think 4 tyres with equal levels of wear and grip is best. Anything can be made to work if you fiddle with it long enough (and have deep pockets|)
Current cars, 2011 FF 4.4 TVD8; Audit TT 1.8T convertible.

I replace all four at a time when they are down to 4mm also run winters and summers. Not the cheapest way to do it but I do lots of miles and drive quite hard so think it is worth it

always replace mine as a set before i read about the diffs so might replace axles in the future