New tyres - Are run-flats essential ? What have you fitted?

[X5_twin]

I need two new front tyres and was wondering what other people have fitted. I currently have 275/40 R20 106w Dunlop SP SPORT MAX which are run-flats.

I was wondering what have other people fitted. Which tyres wear well, give good ride comfort, handling/grip etc. Do I have to fit run-flats. Is there a better alternative to the Dunlops? Can I fit standard tyres, if so how do you deal with a flat tyre with no spare (can of foam maybe?)?

Before I go and buy 2 new Dunlop's any advice would be much appreciated.

Also any advice on good good cheap suppliers. I've used Camskills in the past and found them to be very helpful and cheap.

Thanks in advance folks 



If i can't find the 333m alloys at a reasonable price then I'll buy 2 new front tyres.

[535dboy]

I've always stuck with run flats

You should also do all four at once not just two

[X5Sport]

Why all four at once?  Just curious as I've seen lots of different theories.  With the xDrive having clever front/rear variable ratio splits you're not going to 'wind up' the transmission to the extent something breaks?  The X6 for example, also has a limited slip rear diff which further reduces any 'winding up' - at least I think it does?

Tread wise it makes sense, but not everyone finds that both pairs wear evenly and need doing as a set.  I did find the E53 wore all four evenly but it then spent most of its early life travelling up and down the M6 between home and Manchester so that was as I expected.

As far as needing to stick with RFTs, you don't have to.  If you have the 5-seater then you can buy the underfloor spare retrofit kit (no doubt for a suitable BMW fee!).  Alternatives are as you suggest, the foam 'reinflation' kits or the 'tyresafe' anti-puncture system (not cheap but it works).

[X5_twin]

[quote="X5Sport"]
Why all four at once?  Just curious as I've seen lots of different theories.  With the xDrive having clever front/rear variable ratio splits you're not going to 'wind up' the transmission to the extent something breaks?  The X6 for example, also has a limited slip rear diff which further reduces any 'winding up' - at least I think it does?

Tread wise it makes sense, but not everyone finds that both pairs wear evenly and need doing as a set.  I did find the E53 wore all four evenly but it then spent most of its early life travelling up and down the M6 between home and Manchester so that was as I expected.

As far as needing to stick with RFTs, you don't have to.  If you have the 5-seater then you can buy the underfloor spare retrofit kit (no doubt for a suitable BMW fee!).  Alternatives are as you suggest, the foam 'reinflation' kits or the 'tyresafe' anti-puncture system (not cheap but it works).
[/quote]

I agree, not sure why all 4 need doing at once. I always think you have to do both fronts or both rears at the same time, and never just one tyre, but not sure about all 4 in one go. Unless you can explain otherwise 535d please? . Very happy to educated on the matter ! My rears are still in good condition, maybe have 5mm left. I think I'll do the fronts then the rears later, otherwise I'm looking at approx £1000 for all 4 and throwing away 2 good rears.

I'm happy to stick with run flats as they are so much better these days compared to the days when I had a Mini Copper S some 6 years ago. They were thumpy back then, but the Dunlops I have now seem very good. Also I'm not sure if the tyre foam would work in such a heavy car and such large tyres? Might look into BMW kit but as you say no doubt silly money !

Is there anything better than the Dunlops? Do you both have Dunlops too?

Thanks for the advice guys.

[X5Sport]

Mine came with Dunlop Sportmaxx fitted to the 20" and Bridgestone Dueller HP on the 19".

Like you, I always change an axle set as a pair unless one say has a puncture that can't be fixed and is almost new.  So far the only puncture has been in the front and the tyre was fixed.

[Cannondale]

Not sure it applies to the X but it is recommend that on 4x4 you use the same make of tyres with no more than 3 mm difference of tred.

Some manufacture do tyres for certain makes of car IE Merc, BMW ETC. With Michelin the tyres for BMW fitment should be "star" marked just after the Diamaris. The same size tyre foe a Porsche will have a diffrent symbol. One reason for this is to ensure to tyres are matched on the range of front and rear sizes. There are other factors fitting a set of matching tyres like rolling resistance will be less due to less diff movement meaning better fuel economy.

The compound is also matched to the car giving better handling etc.

I have just put 4 new Michelin Diamaris* on mine, but I am very fussy on tyres. I am sure many will be more than happy with a mix and match approach.

Rich...

[55NF]

I'd never mix & match......  I'll be going non RFT with foam on my 20's next time.        Hate these rock hard RFT's.   

[535dboy]

[quote="Cannondale"]
Not sure it applies to the X but it is recommend that on 4x4 you use the same make of tyres with no more than 3 mm difference of tred.


Rich...
[/quote]

This

Having owned a series of four wheel drive audis and of course the x, every dealer has told me about this to prevent the transmission wind up

I also checked this with my non-dealer tyre fitter friend who had a mobile business and used to look after my lotus tyres etc and he confirmed the same

I would in fact anyway check the other set because they do wear unevenly and you may find that all four need doing anyway, certainly the backs can look deceptively ok and I fact be worn when checked close up all over.

[X5_twin]

Thanks for that 535dboy. I'll have a look at the rears. It may be worth changing all four.

Or if I'm doing all 4 then I'm actually very tempted to stick all 4 wheels and tyres on ebay and then buy a set of the new 333m BMW alloys instead. They look great and I might be able to pick up a used set with tyres at a good price. Worth a look I think.

[X5Sport]

Would you trust a set of 'part worn' tyres (on wheels or not) off somewhere like eBay without knowing the history?  I know I wouldn't.  I wouldn't even buy 'part worns' and second hand wheels & tyres come into the same category.

I'm not suggesting that there is anything actually wrong, but there has to be a shadow of doubt cast over putting an 'unknown history' device on a car in a safety critical position.

The only time I've done it was with a set of brand new and unused wheels and tyres off another X6 that the owner didn't want, and which became my winter set with the tyres being removed and fitted to our X5 which was then sold with a brand new set of RFTs on it.

[Cannondale]

[quote="X5Sport"]
Would you trust a set of 'part worn' tyres (on wheels or not) off somewhere like eBay without knowing the history?  I know I wouldn't.  I wouldn't even buy 'part worns' and second hand wheels & tyres come into the same category.

I'm not suggesting that there is anything actually wrong, but there has to be a shadow of doubt cast over putting an 'unknown history' device on a car in a safety critical position.

The only time I've done it was with a set of brand new and unused wheels and tyres off another X6 that the owner didn't want, and which became my winter set with the tyres being removed and fitted to our X5 which was then sold with a brand new set of RFTs on it.
[/quote]


I know what you are saying but anyone buying a used car is basacally but a set of used wheels and tyres.

Mind I have now had my X for 2 months and I have just fitted 4 new Michelins, the front were down to 3mm but the rears were Toyos which were nearly new, but I am fussy and I work in the tyre industry.


Rich...

[X5Sport]

[quote="Cannondale"]
I know what you are saying but anyone buying a used car is basacally but a set of used wheels and tyres.

Rich...
[/quote]

Indeed, which is why I check them too...

I change at around 3mm as that was what we used to do on all the Police vehicles too, and it made good sense so I've always kept to it too..

Richard

[X5_twin]

[quote="X5Sport"]
Would you trust a set of 'part worn' tyres (on wheels or not) off somewhere like eBay without knowing the history?  I know I wouldn't.  I wouldn't even buy 'part worns' and second hand wheels & tyres come into the same category.
[/quote]

I agree. I was actually thinking that if I have to buy 4 new tyres now is the time to change the wheels too before buying new tyres. I do like the 333m style alloys. I could sell my Msport alloys, with existing tyres thrown in, and get a new set of 333m wheels then buy my 4 new tyres for the new alloys instead.

[X5Sport]

Now that sounds like a good plan..(now I've re-read it again)...

[X5_twin]

Damn damn damn damn damn. It just gets better doesn't it. I've now got a puncture in the rear left. A nail smack in the middle of the tyre. Pressure is still fine, but it now looks like 4 new tyres instead of just the 2 fronts !

I drove to the nearest tyre garage to get a repair as I don't really want to buy a new tyre if I'm going to get rid of my wheels and alloys and change for the 333m alloys. The guy at Kwik fit said he would repair it............. until i mentioned it was a run flat. Is that true?