XSeries-forum

Hi , I posted on here about issue I have with tyres on my car. On full lock the car jumps. People have said it because of the general grabber GT tyres on the car. I've looked at the label on the door post, and it states that 275x40x20 is the smallest 20inch rim tyre for this car. We have 315x35x20 on the back axle . This seem to be the right size wheel and configuration for the car . So does anyone have any knowledge as to what to change to . Having diff oil change next week.

You definitely need to get rid of the Grabbers! I have 275/40/R20 and 315/35R20 on the X6 with 214 type wheels.

Depending upon your budget - and you’re realistically looking at £1k for a full set - your choices are Bridgestone Dueller, Dunlop SP Sportmaxx, Continental ContactSport 5, Hankook (not sure which) and Vredestein (some members have these, but again not sure which tyre) all of which are premium end of the market.

RealOEM lists: https://www.realoem.com/bmw/enUS/showpa ... Id=85_0032
(I’ve used my X6 as the model to base this on but the running gear is the same as the E70). There are other options.

The safest option is to go with ‘’ marked (BMW homologated) tyres but it’s not absolutely essential. Staying at the premium end of the market is less likely to result in issues.

My X6 came with Dunlop SP Sportmaxx and they lasted about 14k miles for the set, as did the ContactSport 5 series. I’ve gone back to using Bridgestone as they just seem to last longer without loss of grip etc. Mine still has less than 70k on it so the current tyres are my 4th set. I have a 19” winter set as well - currently on Pirelli Scorpion winter tyres.

I’ve always stuck with runflats though others find non-RFT give a more supple ride.

The general tyres don't look to have the super aggressive tread pattern I was expecting .More important is tread depth difference front to rear, anymore than 2mm is said to cause issues.
If its jumping bad as you say there should be a code for the transfer box which is due to chain slack .Some have changed the transfer box oil and had good improvement but if things are badly worn then it won't fix that.
I suspect new tyres may not solve your issues assuming thread depth is ok especially as they are all the same make.
Is is the front diff oil you are changing ? as they rarely give any bother more likely to be transfer box.

Thanks for the reply s guys.
Because I have no history of the car I will be changing all oils in due course. I don't have any codes showing for the transfer box , just ones for Nox sensor and add blue rear sensor and a load of other niggles. The car belongs to my partner I've let her read all the post that have found about this problem she wants to put the same size tyre's on all four wheel . She has been very careful driving, not parking where she has to put the car on full lock to get out or in to a space and not doing tight turns. Thanks again.

If you’ve got staggered tyre sizes then you have different wheel sizes so it’s not as simple as putting the same size on all four. The actual wheels at the rear are 1” wider. Fronts are 10J x 20 , rears are 11J x 20. Most BMWs have different front/rear, hence the different tyre sizes.

If you want to go ‘square’ (matching tyre sizes), you’ll need different rims as well.

Yes you are right about the rim size . Our old E53 had equal sizes all round, and the one before that had the same set up as this one . Bought the first E53 off a friend, and gave us a spare couple of back tyres. Didn't have that one for long , bought the second E53 needed new back tyres feeling elated that we had a pair of spares which was sort lived.
Thanks for replying. Dave

Hi if you measure the height of the tyres on your car compared with BMW recommended tyres they can be up to 70mm different to manufacturers star rated tyres . This over time causes the transfer box to go out of sink causing the hopping effect .
The best thing to try is another set of wheels and tyres that are star rated if someone would lone you some just to test ! that way you can rule this out without the expense . I have a set of 18" wheels Bridgestone star rated runflats all 255 55 18 you can try if anywhere near Cumbria !

Hi sid10
Very sorry only just seen your post. Thanks for the reply
that sounds a solid idea about trying other tyres and wheels. I would have taken you up on your kind offer if only I lived closer to you I am in kent . Just trying to not do any full lock maneuvers. It her indoors that forgets, she is very confident at parking in tight spaces and reversing in doesn't worry her.