F56 JCW tyres?

[GT4P]

Have a F56 JCW with 18x7 standard wheels wearing Dunlop Runflats 205/40 18 tyres, car has standard sport suspension.
Looking to ditch runflats and fit 215/40 PS4s all round, anyone done this without problems no spacers no rubbing etc and any advantages/disadvantages over 205/40 apart from being cheaper (about £150 for 4) and slightly wider giving marginal better grip!

[GT4P]

Bobley said:

We dinged a sidewall last week. Ordered a tyre from the local place. I went in today and it was a Y rated none run flat... I wasn't going to mix that with run flats but the price of the right tyre is nuts and no one has them?

I need 2 new tyres and to buy 2 new 18” run flats come to over £400 but 4 new PS4 215/40 18 come in at just over £500 whereas 4 new PS4 205/40 18 are about £700, hence my question

[GT4P]

I also considered swapping out wheels to the 17” 501 track spoke but new wheels with PS4 is about £2k! Even second hand wheels are expensive!
You are better off switching out now for a full set of PS4 for an extra £300 and trying to flog 3 good tyres on eBay!

[GT4P]

Having the Michelin PS4 (215/40x18) fitted Wednesday, what pressures should I run at?
Anyone looking for tyres ATS are doing a good deal on them at the moment!

[GT4P]

Currently running Dunlop Sportmax runflats that came on the car from the factory on ,pressures in manual say 49/44 but I have been running when warm around 44/39 for the last 17k and they have been ok. The Michelin tyres are non RFL so I assume a lower pressure so 36/34 or even lower is my thinking, even the Porsches I have owned which were similar weight or heavier etc only run on 32/30 as I recall!

[GT4P]

“I have fitted 215/40/18 Eagle F1 Asymmetric to my JCW, with a reasonable pressure of ~34 psi all round.
[/quote]

This sounds right to me with maybe slightly lower for the rear 34/32 ? Have you tried this ? Obviously there is only one or two of us in the car but with more people in the car they would need to be 34 all round

[GT4P]

BOR said:

GT4P said:

Dunlop Sportmax runflats

What do you think about those tyres in terms of ride quality?

I'm thinking of getting a set in 17"

Do you no what they haven’t been too bad and have got better with miles, grip and handling are ok but they do give a harsh ride even hitting a very small pothole feels worse than it actually is ! I would have ditched them sooner but I don’t like throwing money down the drain so I bared with them for 5 years and 17k miles!
But honestly go with a non run flat they are so much cheaper to replace

[GT4P]

Quick update, had the Michelin PS4 215/40 18 fitted a couple of days ago.
Not done many miles but first thing I noticed was the improved ride, handling I haven’t noticed much difference yet over the Dunlop Sportmaxx Runflats 205/40 18 as apart from ride they are a pretty good all round tyre.
Currently running 39/36 psi (cold) to start but may lower the to 37/34 psi as the handling feels a bit floaty . Will take a bit of playing around to find what’s best.
These tyres are only 85y but old tyres I think were 95y? So tyre wall a bit softer I believe? So maybe don’t want to go to low on pressures?

Edited by GT4P on Sunday 14th May 09:13

[GT4P]

E-bmw said:

Surely, you would want to put a bit more in to firm the ride up if it is a bit floaty.

When I say floaty is not a good word as the car feels planted but a bit light which tells me too much pressure. I had the alignment done at the same time which had never been done since new.
It is also coming from 18k on the old tyres and later miles poor alignment to something different. But the comfort of the ride is vastly improved.

[GT4P]

Done 8k on the 215/40 18 PS4 and they have been great (went 215 over 205 as cheaper) so I expect the 205 ps4s to be quiet expensive, not sure if there is any need for them on a mini though?