Change run-flats to standard tyres?

GolfBravo

Nearly_Old wrote: »

With 18" wheels the price difference is astronomic:

As previous post 2 No 255x35x18 run flat tyres £564.18 (Event Tyres)
As all 4 tyres will need replacing this year total for run flat tyres: £960.18. The 225x40x18 front tyres are £396.00 for the pair.

Going to Flaken 912's: 2 No 225x40x18 plus 2 No 255x35x18 = £455.18. Even going to Continental Sport Contact 3 comes in at £679.80 so still almost 30% cheaper.

OMG! You're right, 18" RFT prices are just insane!

Eg. Michelin Pilot Sport 2 £303 each (!), and you're lucky to get 10K miles out of them.

System

A company like BMW spend millions on car development and design, which includes suspension set-up in conjunction with wheel / tyre specifications.

BMW have specifications for the type of tyre that can / should be fitted to each model, and also which tyre combination is suitable for each car's suspension characteristics.

But, if you guys think you know more than the BMW designers, then go for it :rotfl:

Oh, and just because a dealer recommends non-run-flat Winter tyres, does not mean that those will be the best match for your car's suspension. The majority of dealer salespeople have little or no technical knowledge, so unless they ask the relevant technician for the correct tyre specifications, I would take what they say with a pinch of salt.
The key is : Only fit tyres that are listed by the manufacturer for your particular car. (So if they do list non-run-flats, use that listed spec of tyre if you wish)

neilmcl

BAA1 wrote: »

Oh, and just because a dealer recommends non-run-flat Winter tyres, does not mean that those will be the best match for your car's suspension. The majority of dealer salespeople have little or no technical knowledge, so unless they ask the relevant technician for the correct tyre specifications, I would take what they say with a pinch of salt.
The key is : Only fit tyres that are listed by the manufacturer for your particular car. (So if they do list non-run-flats, use that listed spec of tyre if you wish)

It's not dealers that are pushing them, it's a national promotion by BMW UK, but if you know better than them, then...;)

Like I posted earlier, it's perfectly OK to use non-RFTs but you have to adjust tyre pressures accordingly.

reeac

Almost 20 years ago I had a Jaguar XJ6 4.0 which had Dunlop [I think] run-flat tyres. I thought that replacements were excessively expensive and so bought 5 regular wheels and tyres straight from the Jaguar factory, fitted them and sold the 5 old ones. Cost plenty but saved in the long run. My point is that there was never any mystique about "specially tuned suspension" etc. I never noticed any difference in the handling.

verydeeppockets

Haven't read any of the posts other than the first one but runflats have stiffer sidewalls, so they do ride a lot harsher than standard tyres. The compound is different too.
As an example, Minis are waaay better on normal tyres - changing to normal tyres on ours was like night and day. Quieter, smoother and much better in the wet.
//M BMWs come with 'proper' tyres as runflats are less predictable on the limit. Tells you all you need to know.
Runflats are a marketing ploy to some extent - I wouldn't bother keeping them to be honest. Also note you should inform your insurance company as technically it's a modification.. although most aren't bothered it's not worth the risk not telling them.

Shimrod

verydeeppockets wrote: »

//M BMWs come with 'proper' tyres as runflats are less predictable on the limit. Tells you all you need to know.

I'm not sure that's the reason. I think it is more likely that you can't get runflat tyres in the very low profile 19" and 20" wheels these cars come with.

On the subject of non-runflat winter tyres, if you check the BMW website http://www.bmw.co.uk/bmwuk/owner/wintertyres_enquiry/subhome/0,,1312_181248203__,00.html

on all the 3 series and 5 series options I looked at, the winter tyres on offer are runflats on 17" wheels. They don't list a winter tyre package for the M series cars.

verydeeppockets

E46 M3s for example came with 18 inch wheels as standard. Never on runflats.
The average reps 320d "MSport" probably comes on 18s nowadays, with runflats.
To be blunt, runflats are carp. Unless you have a puncture.

neilmcl

Shimrod wrote: »

on all the 3 series and 5 series options I looked at, the winter tyres on offer are runflats on 17" wheels. They don't list a winter tyre package for the M series cars.

On most (not all) 17s yes, but the 1 & 3 series get a 16" steel wheel option with non-rft tyres.

Nearly_Old

BAA1 wrote: »

A company like BMW spend millions on car development and design, which includes suspension set-up in conjunction with wheel / tyre specifications.

BMW have specifications for the type of tyre that can / should be fitted to each model, and also which tyre combination is suitable for each car's suspension characteristics.

I can understand that a lot of people that buy BMW's (and we run 2 BMW's) would like to belive this but it is an Urban Myth just a couple of examples:
Front Wishbones and Bushes are common to:
E46 3 Series - all engines (e.g. 316, 318, 320, 325, 328, 330, etc), all models (e.g. saloons, estates, convertibles) produced from Dec98 to Feb05.
E85 Z4 - all engines excluding the 3.2 Z4///M (2.0i to 3.0si)

Early E46's were before run flats were across the range, a 330d produced in Dec04 had two options when new - one run flat and the other non-runflat.

Front anti rollbar and bushes: generally as above but including the E46M3 and the Z4///M

Rear lower wishbone and bushes: All E46, All E85 Z4 plus E83 X3, E83N X3, and E89 Z4.

So key suspension components are individually designed? So a key component on a Z4///M requires the same characteristics as a X3???? In reality each design is a compromise and is largely based on what can be reused from other models as this keeps development and production costs down. Example: the brake discs, pads, calipers and mounting brackets on an 07 2.0sp Z4 are identical to those on a 99 2.8 Z3 - and they were first used on the E36 3 Series in Dec90.

jase1

Is there any reason why the OP didn't realise that the tyres were £1150 to replace before he bought the car?