tyres

[fennmd]

hi
looking for recommendations for 19" tyres for the sport model please
thanks

[marti]

I fit Conti's to all my vehicles.....budget tyres are not the way to go....

[X5Sport]

To reduce the risk of transmission failure you would be better off fitting tyres with the ‘*’ mark in the sidewall.  It means they are made to BMW spec in terms of matched rolling radii.  This is key for cars with ‘staggered setups’  (different sizes front and rear), and avoids transmission wind up.  Worst case is shattered diffs and transfer boxes.

There is a long thread in here to help you decide......

Unfortunately it means premium brands and the price that goes with that.

[fennmd]

thanks people,thought that might be the case

[Richyroos]

I have read the horror stories myself, as I was concerned about my tyres, as I have the staggered set up on mine, and the tyres on it when I bought it earlier this year were slightly different tread depths front to rear, but all the tyres the same make - nowhere near worn out though, roughly 50% worn.

I then had the misfortune to have a non repairable puncture and had to buy a new tyre...…...and of course all the advice is to buy a set of 4 - OUCH!!  I wasn't able to buy a tyre the same make as was fitted, and ended up with a Nexen Roadian to replace the punctured tyre, we were in the wilds of Cornwall on holiday at the time. When we returned I decided - in view of all the warnings, and recommendations to buy a further 3 Nexens, so all the tyres were the same. I wasn't prepared to pay the premium price of * rated tyres, and the Nexens do seem to receive good reports, and so far I am happy with them.


I still find it unbelievable that the front and rear diffs, and the transfer box seem incapable of dealing with slight mismatches in tyre dimensions, particularly as the steered wheels make a big difference when you turn a corner and turn at different speeds. I had an old Land Rover many years ago, and I can quite understand not running that in 4 wheel drive on tarmac, and why that causes transmission wind up, as the drive front and rear is fixed with no middle diff, but you would have thought that a car designed to be permanent 4 wheel drive - like the X5, would be designed to cope with slight mismatches between the 4 wheels, without it wrecking the transfer box and diffs.

[X5Sport]

I believe it is the variable torque transfer system that the xDrive (on BMW at least) uses as the pre-xDrive cars (with fixed ratio split 40:60 front/rear like a LandRover) don’t seem to suffer from it (or are far less prone to that being the trigger) that is the cause.

Because the systems used by Porsche, BMW, Audi, Škoda and Mercedes - and possibly others too - are all ‘variable’ it is this part that causes so many owners to consider what tyres they should use in order to avoid trouble. 

I completely agree that it should not be the case.  It just shows poor design, excessive finance controls by bean bouncers or an over drive to keep weight and complexity down.  Car manufacturers seem to believe that all owners will do as they are told rather than being allowed to make their own sensible decisions.  With zero comeback from used car owners the industry just ignores the issues.

Of course the industry isn’t interested in cars that are out of warranty so they just wash their hands of the situation and shrug their shoulders with a “perhaps you would like to buy a new car sir/madam” approach. 

Allegedly the latest generation X cars have a different transfer box system and this is now either no longer an issue, or is far rarer.

As an aside, I managed a fleet of Landrovers/Discovery’s in the 1990’s/early 2000’s and we had several transfer boxes replaced across the fleet every year with the V8 autos being the worst for it.  Never did find the cause though.

[briankerrys47]

[quote="Richyroos"]
I have read the horror stories myself, as I was concerned about my tyres, as I have the staggered set up on mine, and the tyres on it when I bought it earlier this year were slightly different tread depths front to rear, but all the tyres the same make - nowhere near worn out though, roughly 50% worn.

I then had the misfortune to have a non repairable puncture and had to buy a new tyre...…...and of course all the advice is to buy a set of 4 - OUCH!!  I wasn't able to buy a tyre the same make as was fitted, and ended up with a Nexen Roadian to replace the punctured tyre, we were in the wilds of Cornwall on holiday at the time. When we returned I decided - in view of all the warnings, and recommendations to buy a further 3 Nexens, so all the tyres were the same. I wasn't prepared to pay the premium price of * rated tyres, and the Nexens do seem to receive good reports, and so far I am happy with them.


I still find it unbelievable that the front and rear diffs, and the transfer box seem incapable of dealing with slight mismatches in tyre dimensions, particularly as the steered wheels make a big difference when you turn a corner and turn at different speeds. I had an old Land Rover many years ago, and I can quite understand not running that in 4 wheel drive on tarmac, and why that causes transmission wind up, as the drive front and rear is fixed with no middle diff, but you would have thought that a car designed to be permanent 4 wheel drive - like the X5, would be designed to cope with slight mismatches between the 4 wheels, without it wrecking the transfer box and diffs.
[/quote]

Hello whilst not saying Nexen are best but just for imfo , I had these fitted to mine early 2012 Fronts £242 Rear £270 mileage was 104000, now 123000  have recently noticed slight innerware on rears so will be having this checked (No I do not do a lot of miles ) 

[X5-D-Sport]

I got a matched set of rear rims with 285x45x19 tyres on all 4 corners, & no problems at all.
I mix front to rear to even the wear & inflate to 33psi & get approx 15,000 miles from them.

The fronts wear faster, prob due to engine weight & turning etc, & I replace as a front or rear pair, keeping the best pair on the front to dump motorway surface water at speed.

I have put 70,000 miles on the vehicle often with 3mm tread difference from front to rear with no issues at all.

It is likely that the staggered wheel set-up makes some difference, but with matching rims all round the road handling is much better & front tyre wear is significantly reduced with big rims on front as well as rear.

Just my experience... does not mean any one else has got to like it or agree.


Additionally, I was the lead engineer for chassis & suspension for the Porsche 918 hybrid project, so I know a bit about suspension, brakes & traction...
The other thing I did to my D-Sport, was to lift the front & rear by 50mm, 30mm spacers on rear, 15mm on front & pull the camber in at the strut-tops by 20mm.
Front wheel outer edge tyre scrubbing has ceased completely, & the car drives like it's on rails.

again, its my preference & it works well, giving lots more miles on the front tyres.

[Silverfox58]

Hi sorry to hijack this but I have a sport with 19" wheels on , can you fit different size wheels on. ?????

[X5-D-Sport]

Yes, as long as they have the same rolling circumference on front AND rear

[themoog]

I can confirm that different size / worn tyres front to rear can mess with the diffs. I had two new front Prestivos put on mine about a year before putting new rears on. During that time my diffs clicked and clucked when selecting R from D or vies versa. When all tyres were new (ish) the noise went way so something was clearly amiss with rolling radius difference.

[Silverfox58]

So could I put a set of say 18" or 20"

[X5Sport]

Yes.  Have a look at alloywheelsdirect uk to see what options are available.  The 30d had 17” in basic spec, 19” in Sport.  Options went up to 21”.  20” or larger usually need stick on/rivet on wheel arch extensions as the tread may exceed the arch line.

[Silverfox58]

That's  brilliant thanks

[aruek]

Mine uses 18" same size all around. Will it suffer that much if the rears and front are worn different?

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