[SteveC]

Originally Posted by doughboy

Some seem to be confusing wheel WIDTH with wheel DIAMETER here.

The 17" SE wheels or similar are 8J width, this is the same as the 18" staggered front wheel. Even the rear staggered 18" wheel is only 8.5J.

225 is the standard tyre width for 8J rim width on an 16, 17 or 18 or 19 inch rim, so you won't have narrower tyres by getting a smaller dia rim.

I use 18" 8J MV3 reps with 225/40/18 all round, just as easy to get as the 225/45/17 and only a few quid more.

225 is ample in winter, even with 400bhp

Couple of points further to my post.

I wanted RFTs, in order for the car to remain compliant with the standard BMW spec. for insurance reasons

I actually bought some OEM staggered MV3s 18s (as my car was an M-Sport) but found I simply could not source Winter RFT tyres anywhere. 17s in non-staggered SE sizing were easy.

Insurance wanted £170.00 pa more for a swap to non-OEM wheels...nothing extra for SE standard wheels with RFT winter tyres. Not happy at all with downgraded non-RFTs. They absolutely wanted BMW specified tyres, so check!

BTW, if you want to know everything and I mean everything about tyres sizes, here's a useful website

http://www.carbibles.com/tyre_bible_pg4.html[/URL]

[a11y]

From what I can see, mytyres have quite a few options in the 18" staggered winter tyre sizes at the moment. I just can't decide what to buy...

I think my experience of a slight lack of traction on 225 on my last car was partly the tyres: not exactly premium-branded winters (Kumho KW27s) and partly of 225 vs 255. Because as said above, 225 should be adequate over winter.

[doughboy]

It's the 255/35/18 winter that is hard to get.

Even if you find a pair now, what if you get a bad puncture and need a new one in January, no chance - all sold out.

225/40/18 (front staggered standard) is eady to get as that size is a common sport hatch size. My VRED wintrac extreme were £149 in that size and available at loads of places. The MV3 reps (8J all round) were £300, so £900 for a full set that will sell on with the car (still hardly worn after 3 winters)

Others on here have put non-staggered tyres on staggered wheels for winters, you could run 225/40/18 on front and rear staggered rims as the rear rim in only 13mm wider.

Also, the premium increase for 'modified wheels' which would allow ANY combination of winter/summer/tyres/alloys/spacers is minimal and easily recovered / justified in the savings buying rep wheels and common tyre sizes.

[ALF_E90]

Originally Posted by SteveC

There's a fairly simple answer to your question:

1. Insurance companies don't like non-standard wheels, so best to stay standard

2. Wider wheels on the back in a staggered set-up are not particularly beneficial in Winter, when you're not pushing the limits on dry roads, and are worse in snow and ice, where more width = less downforce psi

3. 18" winter tyres are harder to find and more expensive to buy. 18" in staggered sizes makes it even more complex to find a stockist with the appropriate sizes. Scarcity = £££

4. Too small rim sizes won't clear the brakes

In conclusion, buy the standard, non-staggered SE model wheels for whatever BMW car you've got.

This has several advantages:

There're lots of them on the used market....(they're usually cheaper on Pistoheads than Ebay, for some reason)
They look good
They fit optically and mechanically
They are classified as standard wheels by insurance companies
They are easy to resell when you change cars
They're easy to buy tyres for, with a large brand selection
The width gives optimum snow, ice, cold/wet road performance
The extra sidewall depth helps when potholes open up in winter
You can often get almost new units as car owners upgrade their wheels

+1 to that. Loads of non-staggered SE 17" alloy wheels out there, with 225/45/17 all round that makes for a pretty good compromise - probably better for UK conditions that a real Euro-style 16" wheel and very narrow tyres.

Remember also that narrower tyres are better in standing water (which we do get plenty of in our lovely country) and also that winter tyres shift deep water worse than summers - really wide rear winter tyres might get a bit interesting in standing water at speed...

[doughboy]

Originally Posted by SteveC

Insurance wanted £170.00 pa more for a swap to non-OEM wheels...nothing extra for SE standard wheels with RFT winter tyres. Not happy at all with downgraded non-RFTs. They absolutely wanted BMW specified tyres, so check!
[/URL]

£170 for modded wheels? WTF?

And whats this 'downgraded NON RFTs'?? No one can force you to have RFTs any more than they can force you to have Pirelli tyres or castrol oil.

But thats a different story.

[SteveC]

Originally Posted by doughboy

£170 for modded wheels? WTF?

And whats this 'downgraded NON RFTs'?? No one can force you to have RFTs any more than they can force you to have Pirelli tyres or castrol oil.

But thats a different story.

Yep. Direct Line wanted an extra £170.00 pa for a wheel swap to non-standard items

And of course they can't force you to run RFTs. They can however charge you more or revoke your cover and in the event you don't inform them, refuse to settle a claim in a tyre related incident.

Many insurance companies stipulate OEM spec tyres. If non-RFTs are not OEM spec they are considered a downgrade (i.e a tyre capable of running deflated vs. one which is not)

Don't forget that with insurance companies you're not dealing with human beings with the freedom to reason using logic. You're dealing with computers that are programmed to respond in certain ways depending on the input. For example
Change of wheels = premium adjustment and policy revision
Non standard tyres = decline to insure

Also bear in mind that if you deviate from your policy and fail to notify your insurer, they have the contractual right to suspend your policy. In the eyes of the law, you become an uninsured driver, responsible for your own and any 3rd party claims.
In the end, it all comes down to how BMW have spec'd the tyres for a particular model. If BMW list non-RFTs, no problem. If not, you'd better check your policy

[a11y]

£170 is crazy, but again that sums up a lot of insurance companies. Luckily the company I use are OK with winter wheel use as long as they're OEM wheels that are fitted to some models of the same car, i.e. if 17" are fitted to other models (SE) then they're fine with me fitting them to my 330i M Sport. They're also OK with non-RFTs as long as they're UK legal and the correct load/weight rating.

[Guvernator]

Originally Posted by SteveC

Yep. Direct Line wanted an extra £170.00 pa for a wheel swap to non-standard items

And of course they can't force you to run RFTs. They can however charge you more or revoke your cover and in the event you don't inform them, refuse to settle a claim in a tyre related incident.

Many insurance companies stipulate OEM spec tyres. If non-RFTs are not OEM spec they are considered a downgrade (i.e a tyre capable of running deflated vs. one which is not)

Don't forget that with insurance companies you're not dealing with human beings with the freedom to reason using logic. You're dealing with computers that are programmed to respond in certain ways depending on the input. For example
Change of wheels = premium adjustment and policy revision
Non standard tyres = decline to insure

Also bear in mind that if you deviate from your policy and fail to notify your insurer, they have the contractual right to suspend your policy. In the eyes of the law, you become an uninsured driver, responsible for your own and any 3rd party claims.
In the end, it all comes down to how BMW have spec'd the tyres for a particular model. If BMW list non-RFTs, no problem. If not, you'd better check your policy

Ok, how does this work then if you change the OE RFT's to a set of OE non-rft's? The car may have come with RFT's but most BMW's are also offered with a non-rft option now.

[SteveC]

Originally Posted by Guvernator

Ok, how does this work then if you change the OE RFT's to a set of OE non-rft's? The car may have come with RFT's but most BMW's are also offered with a non-rft option now.

If BMW specify both RFT and non-RFT tyres for your model car then you can run either and still remain within spec. Also bear in mind that not all insurance companies are the same. Some may not care about RFT vs. non_RFT although in my experience most do insist on staying within OEM specs.