255/30/19 - ‘upgrade’ to 255/35/19 (E89)

Braveatom · Post by **Braveatom** » Sun Feb 12, 2023 7:32 pm

Has anyone changed the tyres on the rear of an E89 to a different profile?

The tyres need replacing this week (slow puncture isn’t so slow anymore!) and looking around, 255/35/19 are half the price of 255/30/19, and I assume the ride comfort may benefit. In real terms it means a change in diameter of 25mm, so 12.5mm extra height from the centre.

I’m concerned it’ll rub (biggest concern) , or give incorrect data about milage / speed.

Thanks!

Chris

sars · Post by **sars** » Sun Feb 12, 2023 7:38 pm

Braveatom wrote: ↑Sun Feb 12, 2023 7:32 pm Has anyone changed the tyres on the rear of an E89 to a different profile?

The tyres need replacing this week (slow puncture isn’t so slow anymore!) and looking around, 255/35/19 are half the price of 255/30/19, and I assume the ride comfort may benefit. In real terms it means a change in diameter of 25mm.

I’m concerned it’ll rub (biggest concern) , or give incorrect data about milage / speed.

Thanks!

Chris

It’s been done quite a few times by other forum members here, the plus is improved comfort and less risk to some of the fragile 19” rims. The downside is a slight reduction in both acceleration and fuel efficiency.

Pondrew · Post by **Pondrew** » Sun Feb 12, 2023 7:51 pm

I have 255/35/19 on the rear of my E89 (M-sport suspension). No rubbing problems whatsoever. There is at least 20mm arch gap. Remember you only lose half of the diameter increase in arch gap, as the car rides higher by the other half.

3% speedo difference so will probably make it more accurate as analogue speedos are notorious for being 'optimistic'.

The extra tyre wall should also help a little with comfort and help against wheel cracking.

Not had any DSC issues either.

Mr Tidy · Post by **Mr Tidy** » Sun Feb 12, 2023 8:22 pm

Not an E89 admittedly but I fitted 255/45 x 18 to the rear of my Z4M instead of the OE size of 255/40 x 18 with no issues - if anything it has made the speedo more accurate!

In your case the diameter of the tyre is only going up 5% of 255mm so that's only 12.75mm. Which means you only need another 6.375mm clearance in the wheel-arch.

Pondrew · Post by **Pondrew** » Sun Feb 12, 2023 8:24 pm

Mr Tidy wrote: ↑Sun Feb 12, 2023 8:22 pm In your case the diameter of the tyre is only going up 5% of 255mm so that's only 12.75mm. Which means you only need another 6.375mm clearance in the wheel-arch.

That's the radius Iain. Diameter is double that, so 25.5mm.

biZ4rreMids · Post by **biZ4rreMids** » Sun Feb 12, 2023 8:59 pm

Braveatom wrote: ↑Sun Feb 12, 2023 7:32 pm Has anyone changed the tyres on the rear of an E89 to a different profile?

The tyres need replacing this week (slow puncture isn’t so slow anymore!) and looking around, 255/35/19 are half the price of 255/30/19, and I assume the ride comfort may benefit. In real terms it means a change in diameter of 25mm, so 12.5mm extra height from the centre.

I’m concerned it’ll rub (biggest concern) , or give incorrect data about milage / speed.

Thanks!

Chris

I’ve been running 255/35/19 rears for a few years and definitely no rubbing. Can’t say I’ve noticed any change to the accuracy of the Speedo either but a big improvement in comfort (set at 36psi) over the runflats that the current tyres replaced.

Braveatom · Post by **Braveatom** » Sun Feb 12, 2023 9:43 pm

Wow, thanks for all the great replies, it’s exactly the info I was after and then some.

Think I’ll do it - it appears to be a net benefit. Both my rear alloys are cracked and need sorting, so saving £250 on a pair of tyres is really gonna ease the pain.

Argyll Andy · Post by **Argyll Andy** » Sun Feb 12, 2023 9:54 pm

I went up to 265/30/19 with no issues. The increase to the sidewall because of the slightly wider tyre gave a bit more protection to the rim

Z4Shane007homas · Post by **Z4Shane007homas** » Thu Feb 16, 2023 8:35 pm

I thought about doing this myself with the rear tyres - as all 4 need replacing on mine.

Which is the best website to purchase tyres online ?

Pondrew · Post by **Pondrew** » Thu Feb 16, 2023 8:44 pm

Z4Shane007homas wrote: ↑Thu Feb 16, 2023 8:35 pm Which is the best website to purchase tyres online ?

Unless you can get them fitted for free, I've not seen a saving on buying online TBH.

I just ring round my local tyre garages and get quotes for the tyres I want. One or other usually beats the online people.

When I lived in your area, I always used the tyre garage in Piddington (on the A40 past West Wycombe going towards Stokenchurch). Or Adams & Page on Cressex estate.

ronk · Post by **ronk** » Sun Feb 19, 2023 10:22 pm

Im going to buy new tyres in the spring and will probably do 35 profile rears - it seems well documented that its ok - but should the fronts just remain at the standard 35 profile?

Currently looking at the Conti Contact 7's

True-Blue · Post by **True-Blue** » Tue Feb 28, 2023 1:15 pm

ronk wrote: ↑Sun Feb 19, 2023 10:22 pm Im going to buy new tyres in the spring and will probably do 35 profile rears - it seems well documented that its ok - but should the fronts just remain at the standard 35 profile?

Currently looking at the Conti Contact 7's

Yes, 225/35/19 or 235/35/19 will work fine with 255/35/19 rears

My VO E89 had the 235/35/19 & 255/35/19 Combo, and I’m just about to fit 225/35/19 & 255/35/19 onto my DSB E89

The VO had 9J fronts and 10J rears - the DSB has 8J fronts and 9J rears.

ronk · Post by **ronk** » Tue Feb 28, 2023 2:17 pm

Thanks.
Now the search begins.
I t think my choice is between Conti 7 snd Michelin ps4
The Conti do seem a lot cheaper- but some reports say they have a better feel.

warmasice · Post by **warmasice** » Tue Feb 28, 2023 6:12 pm

Argyll Andy wrote: ↑Sun Feb 12, 2023 9:54 pm I went up to 265/30/19 with no issues. The increase to the sidewall because of the slightly wider tyre gave a bit more protection to the rim

This seems to be a better shout than 255/35.

True-Blue · Post by **True-Blue** » Tue Feb 28, 2023 6:17 pm

warmasice wrote: ↑Tue Feb 28, 2023 6:12 pm
Argyll Andy wrote: ↑Sun Feb 12, 2023 9:54 pm I went up to 265/30/19 with no issues. The increase to the sidewall because of the slightly wider tyre gave a bit more protection to the rim
This seems to be a better shout than 255/35.

Far more expensive though

Z4-forum.com

Z4-forum.com