G20 tyre query - 255/40R18 v 255/45R18

[DibblyDobbler]

Gents (and Ladies?) - sorry in advance as this is rather dull...

I have a G20 330i currently running on 19s with run flats - I am going to change the tyres to non-RFT and I was pondering if it would be sensible to change to 18s at the same time (for a smoother ride - I am in my mid 50s and this is important to me)

The recommended size for an 18 inch rear is 255/40R18 but the tyres I prefer (Crossclimate2) are only available in 255/35R18 or 255/45R18.

If anything I would go for the 255/45 instead of the 255/40 - which I believe are around 3.7% bigger. Has anybody done this or have a view as to whether it would be a bad idea?

Thanks in advance, Mike

[d_a_n1979]

DibblyDobbler said:

Gents (and Ladies?) - sorry in advance as this is rather dull...

I have a G20 330i currently running on 19s with run flats - I am going to change the tyres to non-RFT and I was pondering if it would be sensible to change to 18s at the same time (for a smoother ride - I am in my mid 50s and this is important to me)

The recommended size for an 18 inch rear is 255/40R18 but the tyres I prefer (Crossclimate2) are only available in 255/35R18 or 255/45R18.

If anything I would go for the 255/45 instead of the 255/40 - which I believe are around 3.7% bigger. Has anybody done this or have a view as to whether it would be a bad idea?

Thanks in advance, Mike

I've always used: https://www.willtheyfit.com/ and stuck within the 2.5% +/- region as to not affect speedo/diff/box etc...

If you want all seasons, the Goodyear Vector Gen 3s are superb tyres and as well reviewed as the Michelins

However, when I had my F01; I dropped from 20" RFTs to 19" non RFTs and they transformed the ride superbly; I'd say try 19s first and see how you get on

[DibblyDobbler]

d_a_n1979 said:

I've always used: https://www.willtheyfit.com/ and stuck within the 2.5% +/- region as to not affect speedo/diff/box etc...

If you want all seasons, the Goodyear Vector Gen 3s are superb tyres and as well reviewed as the Michelins

However, when I had my F01; I dropped from 20" RFTs to 19" non RFTs and they transformed the ride superbly; I'd say try 19s first and see how you get on

Thanks Dan - yes agreed, my feeling was the size difference was pushing it a bit but I'm by no means an expert...

The Goodyears look decent but I can't see a 255/40R18 in the usual sites (any suggestions appreciated) so that leaves me with the same dilemma.

Trying non-RFTs on the 19 inch wheels I have is probably what I'll end up doing - I guess I was just wondering if I should be looking to kill 2 birds with 1 stone and go to 18s at the same time. The ride is not terrible even on the RFTs so maybe that would be enough.

Cheers

[d_a_n1979]

DibblyDobbler said:

d_a_n1979 said:

I've always used: https://www.willtheyfit.com/ and stuck within the 2.5% +/- region as to not affect speedo/diff/box etc...

If you want all seasons, the Goodyear Vector Gen 3s are superb tyres and as well reviewed as the Michelins

However, when I had my F01; I dropped from 20" RFTs to 19" non RFTs and they transformed the ride superbly; I'd say try 19s first and see how you get on

Thanks Dan - yes agreed, my feeling was the size difference was pushing it a bit but I'm by no means an expert...

The Goodyears look decent but I can't see a 255/40R18 in the usual sites (any suggestions appreciated) so that leaves me with the same dilemma.

Trying non-RFTs on the 19 inch wheels I have is probably what I'll end up doing - I guess I was just wondering if I should be looking to kill 2 birds with 1 stone and go to 18s at the same time. The ride is not terrible even on the RFTs so maybe that would be enough.

Cheers

It's all about how you feel dropping to 18s will benefit the most...

I sold the 19s with RFTs on my F31 the weekend I got it; the test drive was bad enough and knew they were going. Bought a set of 18s with winter RFTs and they did us superbly up to the Highlands & back in Feb and then bought another set of 18s to fit summer non RFTs to... Which are now on the car and it's so, os much better for them!

I'll be fitting non RFT winters to the straight set of 18x8s I've got for winters as well, once they're refurbed!

I'd say try the 19s first and see how you get on; are you dead-set on all seasons though? Could you run the 19s with summers and the 18s with winters, or haven't you room for 2 sets of wheels etc?

[DibblyDobbler]

d_a_n1979 said:

It's all about how you feel dropping to 18s will benefit the most...

I sold the 19s with RFTs on my F31 the weekend I got it; the test drive was bad enough and knew they were going. Bought a set of 18s with winter RFTs and they did us superbly up to the Highlands & back in Feb and then bought another set of 18s to fit summer non RFTs to... Which are now on the car and it's so, os much better for them!

I'll be fitting non RFT winters to the straight set of 18x8s I've got for winters as well, once they're refurbed!

I'd say try the 19s first and see how you get on; are you dead-set on all seasons though? Could you run the 19s with summers and the 18s with winters, or haven't you room for 2 sets of wheels etc?

Thanks again Dan. I'm keen on all season as we stay in Edinburgh so frost, snow etc is moderately frequent and I don't want to get stuck (Mrs DD runs an MX5 and it doesn't go out in the snow!) - in theory I could run 2 sets but I've been on CC+ for 4/5 years and found them to be fine year round (I like to put my foot down every so often but I don't throw the car around) - appreciate 2 sets of wheels/tyres is the ideal solution but in all truth I can't be bothered with the hassle.

I have found that the Continental All Season Contact comes in 255/40R18 so that's an 18 inch option or else go with plan A and just keep the wheels I've got and stick CC2s on them (I'll forget about 255/45R18).

Cheers

[Pica-Pica]

On my F30 335d, I got rid of my 19” wheels, and went to 18”. I kept runflats though, and went from 19” Pirelli, to 18” Goodyear EfficientGrip. That made a big difference in comfort and noise; a much better car to live with after that. Whatever tyre tread type, I think you will eventually want to go to 18”

[DibblyDobbler]

Pica-Pica said:

On my F30 335d, I got rid of my 19” wheels, and went to 18”. I kept runflats though, and went from 19” Pirelli, to 18” Goodyear EfficientGrip. That made a big difference in comfort and noise; a much better car to live with after that. Whatever tyre tread type, I think you will eventually want to go to 18”

Thanks for the comment . This is what I was wondering and I don't want to fork out for another set of 19 inch tyres only to decide later I should have gone to 18s... if they had CC2 in the correct size I'd be going for it but I'll need to look into the Conti all season to see if they're going to work...

Cheers

[rottenegg]

I would try non-run flat 19s first. I was all set to throw mine in the bin and drop down to 18s, but simply binning the truly awful 19" P Zero RFTs in favour of Continental Sport Contact 7 was a game changer, both in comfort and grip. By a huge margin, on both.

P Zeros are utter garbage. I have no idea why they get good reviews.

[DibblyDobbler]

rottenegg said:

I would try non-run flat 19s first. I was all set to throw mine in the bin and drop down to 18s, but simply binning the truly awful 19" P Zero RFTs in favour of Continental Sport Contact 7 was a game changer, both in comfort and grip. By a huge margin, on both.

P Zeros are utter garbage. I have no idea why they get good reviews.

Thanks for the comment - yes I suspect that will be my first move as the tyres I prefer are readily availabe in the right size for 19s (but not 18s) and the ride is really not that bad on comfort mode so that should be enough I hope! Cheers

[rottenegg]

The problem is, the F & G 3 series just look so much better on 19s! Proportionally perfect. 18s look small and 20s look silly. So I couldn't let my 19s go for that reason really, in spite of knowing it would drive better on 18s, lol. The price of vanity I suppose.

[DibblyDobbler]

rottenegg said:

The problem is, the F & G 3 series just look so much better on 19s! Proportionally perfect. 18s look small and 20s look silly. So I couldn't let my 19s go for that reason really, in spite of knowing it would drive better on 18s, lol. The price of vanity I suppose.

Yes agreed - reckon I will do the same

[sam.rog]

I have 18 inch Michelin ps4 non rft on my g20 330e. The ride is really good and comfortable. I’ve not been in a rft 19 inch equipped car so can’t compare directly.

[d_a_n1979]

Re 18s vs 19s

Personal preference but 18s don't look small/ lost at all with the right tyres



Makes the brakes look better too

Plus most OEM 19s are bloody heavy...!