Move to 18 Inch Rims?

[CarNoir]

Hello all....  First post.

I have an E70 3.0sd, built May 2008. Two and a half years ago I got the ache with Brigestone runflats on the 19 inch 'standard' staggered setup, and fitted Vredenstein winter tyres. Not star-marked, of course.

I have since then read the many entries on this excellent forum about the dangers of dissimilar rolling radii, and the potentially costly results. I am now at the point where the 285/45 rears have 5mm of trad left,the 255/50 fronts had....  8mm left. I said had, because a front just grew a big blister in the sidewall for no apparent reason, so I was forced to replace it.

So this brings matters to a head. I have (don't laugh) been putting a little more air in the rears (10%?) to make them bigger. And to make me feel better. This can't go on, so I believe 'correct' courses of action available are  a)  Dump the Vredensteins and return to star-marked tyres, or  b) buy 18 inch rims and 255/55 tyres to suit. Probably winter again, and run them all year.

I hate runflats, and got them off my 2007 E61 as soon as I could. The improvement when I took them off the E70 was huge.

I am, therefore, leaning towards the 18 inch rim option. Whilst the one-off cost of the rims is significant the tyres to fit could cost just £400 - ish, and for a 'name' at that. A set of runflats is about £700. In about 40k miles the rims are paid-for by the more economic tyre setup. The ride is 'hard'; the car has the 'sport' damper setup, the change to 55% aspect ratio would help, losing the 285s at the back would help snow performance, AND... as I consistently get more wear at the rear, I can move the tyres around to equalise wear -not so with a staggered setup.

What have I missed, please?  I drive like my grandad (and I'm 66) so won't miss 'wider tyres'. In fact, the staggered setup seems to be more for 'looks' than anything else. I really don't care about looks.

My old dad once said 'there's two kinds of car (melad) - them as goes and them as don't'. So I guess you can see where I'm coming from. Iknow that these cars are sensitive to tyres, I want mine to 'keep going'

I would really appreciate views on this.  Thanks.

[X5Sport]

Firstly aboard.....

Secondly don't feel you gave to stick to runflats.  BMW also fit non-RFT to their cars which gives you another option before spending out unnecessarily.

The key bit with the tyres, especially on staggered setups is as you imply, the circumference.  Staying within 1% between axles is the BMW spec - regardless of being '*' marked.  The marking just indicates that a set will be within that tolerance at new.  The tyres should wear evenly (both my E53 and E71 with staggered sets wear this way) so the difference should stay in limit.

And you may be right about the 'looks' for the staggered set up as a 'square' set up just looks lost in the arches.

I run a 20" staggered (Summer) and 19" staggered (winter).  OK both run '*' marked RFT but only because I can't be a**ed with tyre goo and need the underfloor for luggage rather than a spare.  I have only done 35,000 miles from new in the X6.

[CarNoir]

Thanks!  First response from the 'boss'....  Much appreciated

I do understand what you say, and yes I've seen that you can get starred non-RFT

You've highlighted a major point, in that I get unequal wear front/rear - both on the E70 and E61. The latter car I get 45k miles rear, 60k miles front - terminal punctures permitting of course. The car has travelled 123k miles, 100k of that with me. The E70 with current tyres has travelled 19k miles, miles on the clock 76k. So, as I've already implied me/wife are very easy on the rubber, as it were. So for me, unequal is normal.  I do recall that in previous posts you (and others) have said that you get even front/rear wear, and found that striking as nearly all of the time only the rears are 'driven' in that they do the work.

I wonder if my front and rear axles are actually connected like other X5s......?  What? Well looking underneath all the right bits do seem to be there. But the car's not seen snow in the 3 winters I've had it (in Kent), and I've not been off-road.

Regarding the rear 18s getting a bit 'lost' in the bodywork, one can specify a boss which extends the rears 40mm outwards, and allegedly all looks ok. It just means that you have to actually rotate tyres, ie not wheel/tyres.

Well, lets see if others have comments

Thanks again

[sid10]

Hi I would steer away from fitting after market spacers as A . quite a lot of insurers arent keen on insuring them as I found out when I rang them about mine , B . the whole idea of fitting none staggered wheels for winter driving is for the rear  wheels to follow the fronts creating better traction .
2nd option is to fit a set of 19" none staggered 19" that BMW did for the E70 , front and rear are the same size and offset so you can rotate tyres front to back etc , to ensure a more even wear .
3rd option is just replace the excellent Vredestein tyres .

Do your tyres wear uneven as most X5 / X6 cars do ? Mine tend to go through rears faster than the front too much camber is normally the case but I checked a new set of 20" Dunlops last year the fronts were 8.1mm & rears were 6.8mm so quite possibly they arent the same to start off with .
      regards
          Sid10

[X5Sport]

I'm not the 'boss', that's pvr or AW8.  I'm just a nerd who likes engineering and cars.....HTH though 

[CarNoir]

Well we've all got our specialities.

Now concrete..........  I'm your man.

[CarNoir]

Reply to Sid10

The 18" rims I am considering can be specified with an integral 40mm extended boss for the rears, so no separate spacers involved. This (reportedly) fills-out the rear wheel arches ok.

Here is a link:  https://www.tyremen.co.uk/wheels/18-design-e-2

The comment suggesting the possibility of new Vredensteins has struck a chord; I could replace the two rears only at £360 plus fitting and the front/rear tread depths would converge.  No stars, however.

Whilst I get faster rear wear, overall wear across the tread is pretty even. However, as the previous Bridgestone RFTs got to the end of their lives, the characteristic BMW wear on the inner edges of the rears showed.

I do believe that the BMW recommended 2.2 Bar pressure for the 19" staggered setup is a little low. A slightly higher pressure keeps the inner tread (rear) wear at bay for longer.

Decision sooooon!

[Horizon]

The rims say for X5's before 2007, which is the E53, you have an E70. The centre spigot is larger on the E70.
So check with them before purchasing.
A lot of NON OEM wheels need spigot rings as they are multi figment. But see if yours are E70 compatible before ordering

[CarNoir]

Thanks for the advice.

I'm still thinking about what to do, complicated by being in France. If I do go the 18" rims route I'll have a long phone conversation with the UK supplier before I do anything.

My current thought is to replace the rear Vredenstein winters with new.

Thanks again.