Tyre's Mixed or Not

[Woodenman]

Picked up my X5 40d msport just over a month or two back now.

When i bought it one of the front tyres had been damaged (egg) so they changed the 2 fronts to Michelin(Goodyear actually) Excellence Runflats (seem like a nice tyre) and they left the 2 Conti runflats on the back which have about 5 mm tread left.

Problem is went to get the wheel balanced last night as i lost some weights and i thought what the hell balance all round. The guys at the local are good chaps... But on taking the rear tyres off one has been embedded with some funky metal crap (packing crate style stuff) and although the tyre when this was removed dosnt leak i dont like the idea of it (and the tyre boys said it isnt ideal although probably not dangerous (plus they only had Falken non RF in stock).

My problem is due to run flat ride quality i was going to let the rears wear down a bit more and swap em all to non r flats like vredestin or another mid to good named tyre? I have got a slime kit and jack from a previous car so no issue and mobility breakdown.

Can i put non runflats on the back ? should i just replace with RF (offered Bridgestone at £225+vat). Or should i put all new non runflat front and back.

Its a bit of a ball ache as I just dolled out allot on money on the house and needed a quiet 2 months

Please dont advise me to get Kinforest like my mate in the pub they are great on his focus

Advice please guys. or links to awesome tyre deals.

[X5Sport]

A couple of things to be aware of when you actually decide which way to go.

Using non '*' marked (made to BMW OEM spec) will put your transmission at risk.  That is not to say it will break, just that there are increasing examples of it happening when non standard tyres have been used.  There is no common issue with a particular manufacturer or type, but there does seem to be something about non '*' tyres that upsets these cars.  They are soft-roaders, not off-roaders and it seems that may be significant.

Using non-RFT/RFT tyres mix between axles poses no problem, nor does using non-RFT all round, from a handling perspective.

A wide wear variance between axles also increases the risk of either a broken diff or transfer box.  Some owners have absolutely no issues at all whilst others have unexpected and expensive bills for either of the above.

Only use the correct sizes as again any variance will break something.  If you have a BMW Warranty, they may (probably will) walk away from any problems if you use non 'as factory' tyres.  Dealers and BMW GB are very good at playing that card.  >:(

[sid10]

Hi why not just put 2 more Michelin rft on the back wait until they all run out then change to none runflat ! Michelin were doing a £50 cash back on their tyres or £100 if you bought 4 money was on a fuel card I bought a set for my wifes X1 all was good !
  I think Costco do offers on Michelin aswell worth a look although you need to join about £25 .
What size are your wheels ? I have also bought from Oponeo on the net tyres were 1/3rd cheaper & fairly new date codes . I would stick to Branded tyres Michelin , Bridgestone , Continental although I have Vredestein Xtreme 4 on my winter wheels . They are a great tyre although they are a bit noisy compared with the Bridgestone runflats .
  If you do a lot of mileage I recommend getting a set of winters swapping them over November to April saves your summer wheels & winter tyres have a softer compound so wear better saving alround .

[Woodenman]

Thanks for the advice guys.

I looked for a pair of Michelin(goodyear because im a noob) but they dont do them in 315 35 r20.

I will probably end up getting 2 bridgestone I will just try to get a better deal.

As for winter tyres ive just had to explain to my wife who believe all 4x4 are awesome in the snow that her little runabout will be better

I will have a look on Oponeo.

[Tommy]

I have non rft

Pirelli on the front, and Rf Bridgestone on the rear. No issues. I've done it many times over the years. Keep tread depth matched, or transfer box will whine.

[Woodenman]

Thanks for the advice guys.

I can get 2 x Bridgestones XL RF BMW * Approved for £495 fitted which seems about as cheap as non run flat tyres. (are they any good?)

Im worried about changing to non approved non runflats although the dealer i bought it from fitted Goodyear Excellence RF XL which arnt BMW approved but seeing as they are VAG approved thats probably why (VAG dealer group sold me the car).

My car is outside its BMW warranty now as its a 10 plate. But i was going to get a driveline warranty when the dealers cover finishes at the start of next year (not sure on cost) as the BMW is more complicated than any previous car ive had.

Is this then true that they will not cover the car as it has these Goodyear tyres on the front?

If im honest nearly all my cars previously have had everything from Kumo's, Avons,Cooper,Pirelli,Conti's etc through to chinese tyres that i bought a car with and after taking a drift session in the wet promptly got rid of?

I had assumed like an Impreza or Evo that i ideally just need matching tread depth? and change the set in one go? hence why i was going to change them anyway.

[X5Sport]

Yes you need to watch tread depth, and it will be up to BMW - if you buy their driveline cover - as to whether or not you are covered.

[Woodenman]

Found these on Tyreleader

http://www.tyreleader.co.uk/car-tyres/h ... 10y-257304

Anyone used Hankook on the X5 they look a good price and Hankook supposedly are an OEM for the new X5?

Really thinking of ditching the runflat tyres i do not like there characteristics.

[X5Sport]

Hankook (Ventus?) RFTs are indeed used, but only up to 18" and not with sport brake equipped cars.

[shadrack]

just on a side note, my recently bought car auc had 4 x new tyres fitted before colllection, i noticed however they put dunlop rears on and bridgestone (i think) fronts, they are all rft and are all * rated just why not fit 4x of one brand as i would have done

[X5Sport]

Probably old stock.....

[kkx5]

It's been on this forum 100's of time...Buy cheap, non bmw aproved tyres.... pay a lot for transfer repair. Its e70  ...not a ford focus...

[AwB]

I'm now in the market for new boots and will replace all four at once.  I don't want to mix brands, wear or RFT/non-RFT.  2012 E70 m-sport running staggered 315/35R20 and 275/40R20.  Interested in the debate of (*) marked or not - I know there have been loads of posts on the topic already

Under my setup, there is theoretically a 2mm difference in rolling circumference between front (2,285mm) and back (2,287mm) tyres when new, assuming manufacturing tolerances are exact(!) and inflation pressures / load are balanced equally. The implication is that, at 100km/hr, the slightly larger rears will be trying to drive the car 0.1km/hr faster than the fronts.  The transfer box is supposed to cope with this imbalance.

Now, suppose there was a 3mm tread difference between worn fronts and new rears. That's an additional c.19mm difference in rolling circumference and at 100km/hr the rears will want to go 1.0km/hr faster than the fronts. 

This effect is presumably the cause of potential x-drive transfer box issues, i.e. when a difference between axles is outside of tolerance.

BUT... have (*) marked tyres really been manufactured differently (or shaved), so that staggered pairs have the exact same circumference, or have they simply been tested to ensure the difference is within tolerance?

The docs for my BMW fully comp warranty do not reference star-marks and the manual simply states: "For each tire size, the manufacturer of your vehicle recommends certain tire brands. These can be identified by a star on the tire sidewall.  With proper use, these tires meet the highest standards for safety and handling"  This doesn't sound like a requirement to me...

[X5Sport]

'*' marked tyres are allegedly correctly sized.  Other manufacturers do the same so it's not unique to BMW.  'MO' is the Merc version.

What I found with BMW and their warranty is that if the parts are not 'as offered' on a new build - eg as the car would be straight off the production line - then they are inclined to try to wriggle out of paying.  The wording is as you say just a recommendation, however BMW GB (or their insurer who provides the cover) may decide to use an alternative interpretation.

Common sense should prevail and in many cases most likely will, but some Dealers will put a report into BMW and for some unclear reason they just will not play.  It's this inconsistency I found so frustrating.

[The Mechanic]

I have just collect my 2012 X5 30D MSport from the local BMW dealer after a routine service.  The Service guy said that it needs two new front tyres.  I asked him if it was a problem with new tyres on the front and not new on the back since the tread depth will be different.  His answer was that as long as the tyres are the same on the same axle then it is not an issue.  That seems to be contrary to some of the advice on here.  BTW, they wanted £404 + VAT for two front tyres and the service guy could not even tell me what tyres they were proposing to fit, only that they would be BMW approved.  Needless to say, I declined their kind offer.