UK roads traction....tyre size

[ianm5]

I know there’s a tyre thread but a lot of the discussion is from USA where the road situation is generally completely different.

I’ve seen a couple of mentions of wider rear tyres, is this on the standard rims & are spacers required?

What’s the feel like on a UK road? Does it make much difference for traction on a dry straight? What about greasy broken backroads?

Thanks for any replies, I’m kind of thinking the M5 might be here to stay so toying with some upgrades. I’m not looking to track the car or even ‘drive fast’, I’d just like to be able to see a bit more of the acceleration day to day without blinky the never ending TC light, although I don’t trust MDM or below on the TC.

[M5 TT]

I went from 295 MPSS to 305 MPS4s and it made a big difference. I guess some of that would be down to the 4s tyre but deffo worth doing. No spacers required.


My car was mapped (around 700bhp) and I could just about put all the power down in 3rd on a damp road and easily 2nd gear on a dry road.

I did remove my rear camber as well though. No-one believed it would make any difference, certainly seemed to work for me. I was happy with the grip once the tyres had some heat in them. Tyres needed to be above 15 degC to work. Pretty easy to reach that temp with normal driving even in the cold and wet

[ianm5]

Thanks - I hadn’t realised the S4 was so much better than the SS too

Do the 305s just sit correctly in the rim?

[M5 TT]

Yes big difference between the SS and 4S. 305 sat perfect on the rims. looked great

[Barry_S]

Originally Posted by M5 TT

Yes big difference between the SS and 4S. 305 sat perfect on the rims. looked great

I did the same with a 5mm spacer on the rear and a 3/4" drop with KW HAS.

Love the look and was very impressed with the additional traction.

[M5Rick]

I've got the 305's ps4's also with 5mm spacers, it's better grip from standing start than 295's and the handling is not affected on fast bends.Need the pilots on the front also as having mix with say super sports on front won't give you that assurance when in 'extremis'.

[Guy M5]

305's S4's here, no spacers, works well.

[D4T]

Does this apply to all wheel sizes? Wasn't sure if the 19" wheels are a different width to the 20"'s? (I have the 343M's so am assuming I'm ok for 305's)

[M5Rick]

Originally Posted by D4T

Does this apply to all wheel sizes? Wasn't sure if the 19" wheels are a different width to the 20"'s? (I have the 343M's so am assuming I'm ok for 305's)

Yes 305/30's okay for the rear 20'' 343m.

[D4T]

Originally Posted by M5theonlyone

Yes 305/30's okay for the rear 20'' 343m.

Thanks for confirming! Out of interest is it not on the 19"s then?

[M5Rick]

Originally Posted by D4T

Thanks for confirming! Out of interest is it not on the 19"s then?

On the 19's the base sizes are 265/40 front and 295/35 rear so a mite more softer on these.

[D4T]

Originally Posted by M5theonlyone

On the 19's the base sizes are 265/40 front and 295/35 rear so a mite more softer on these.

I see but the same width wheel.. got it

[M5Rick]

Originally Posted by D4T

I see but the same width wheel.. got it

19'' wheel sizes
9Jx19 ET32
10Jx19 ET34

20''wheel sizes
9Jx20 ET34
10Jx20 ET34

[D4T]

Originally Posted by M5theonlyone

19'' wheel sizes
9Jx19 ET32
10Jx19 ET34

20''wheel sizes
9Jx20 ET34
10Jx20 ET34

Awesome thanks

[BalSingh]

I’m running 265 35 20 fronts and 305 30 20 rears on aftermarket wheels.

Had Pirelli’s on the rear but changed to MPS4 which makes a world of difference in the wet.

[D4T]

Originally Posted by BalSingh

I’m running 265 35 20 fronts and 305 30 20 rears on aftermarket wheels.

Had Pirelli’s on the rear but changed to MPS4 which makes a world of difference in the wet.

How about the MPS4 in the dry? I've got P Zero's and can't help but thinking they're just a bit crap on this car all round.

[Blaxwil]

Night and day difference with the MPS4's. I've run PZero, Pilot Sport and the 4's are noticeably better all around than the Pirelli. Hands down.

[BalSingh]

Originally Posted by D4T

How about the MPS4 in the dry? I've got P Zero's and can't help but thinking they're just a bit crap on this car all round.

Dry they’re not too bad but the Michelin’s just feel more ‘sticky’...almost a softer compound and that’s noticeable over bumps and ruts etc. Not just in handling.

Wet; they’re a completely different beast. Sometimes with the Pirelli’s moving off from a roundabout in the wet it would spin up, but not with the Michelin’s.