Run Flats or Not Run Flats

[enuff_zed]

Just looked at mine in the garage. Can't get a decent photo due to the light, but:

225/40 Front = 2.5 bar
255/35 Rear = 2.7 bar

I'm now on non-RFTs and prefer PSI, so after much experimentation I'm running them 34psi front and 36 psi rear.

Hope that helps?

Preferring PSI, as I do, or not, 2.5 bar is approximately 36 and 2.7 bar is 39.

I am aware the figures I quoted don't match.
The OP wanted to see the book figures and I then told him what my 'bum-ometer' ended up with on non-RFTs.
Either way it seems he is running lower pressures and the same front and rear.
Air is free so there's a cheap starting point.

 

[Silverstar]

Just looked at mine in the garage. Can't get a decent photo due to the light, but:

225/40 Front = 2.5 bar
255/35 Rear = 2.7 bar

I'm now on non-RFTs and prefer PSI, so after much experimentation I'm running them 34psi front and 36 psi rear.

Hope that helps?

I am pretty sure 18" should be 2.5 bars front and 3.0 bars rear, although I can't check the label right now as my car is in the garage.

 

[enuff_zed]

Just looked at mine in the garage. Can't get a decent photo due to the light, but:

225/40 Front = 2.5 bar
255/35 Rear = 2.7 bar

I'm now on non-RFTs and prefer PSI, so after much experimentation I'm running them 34psi front and 36 psi rear.

Hope that helps?

I am pretty sure 18" should be 2.5 bars front and 3.0 bars rear, although I can't check the label right now as my car is in the garage.

Well maybe you have a different label?
This is for a 64-plate 20i, so similar to the OPs.

 

[Silverstar]

Just looked at mine in the garage. Can't get a decent photo due to the light, but:

225/40 Front = 2.5 bar
255/35 Rear = 2.7 bar

I'm now on non-RFTs and prefer PSI, so after much experimentation I'm running them 34psi front and 36 psi rear.

Hope that helps?

I am pretty sure 18" should be 2.5 bars front and 3.0 bars rear, although I can't check the label right now as my car is in the garage.

Well maybe you have a different label?
This is for a 64-plate 20i, so similar to the OPs.

Ah didn't think of that, mine is a 30i

 

[enuff_zed]

I am pretty sure 18" should be 2.5 bars front and 3.0 bars rear, although I can't check the label right now as my car is in the garage.

Well maybe you have a different label?
This is for a 64-plate 20i, so similar to the OPs.

Ah didn't think of that, mine is a 30i

Keep up at the back.

 

[Silverstar]

Well maybe you have a different label?
This is for a 64-plate 20i, so similar to the OPs.

Ah didn't think of that, mine is a 30i

Keep up at the back.

 

[inkey$]

Before I commit to spending £500 on a new matching set of non-run flat tyres, I've booked the car in to my local Indy BMW workshop, Hallmark Autos of Maldon (any one know them?) on Monday. I've asked them to carry out a thorough inspection of the car, which should show up any hidden defects.

The dealer I bought it from, View Autos, did their own pre-sales check and an oil service, but I will feel happier with my own independent assessment.

Keep us all posted on how you get on

 

[jamesgarbett]

What;s the view on adjusting to slightly different tyre widths/profiles to OEM on 19" wheels? Any benefit/disadvantage?

 

[sars]

What;s the view on adjusting to slightly different tyre widths/profiles to OEM on 19" wheels? Any benefit/disadvantage?

That's a bigger can of worms than the RFT issue, there are many who have changed widths or profile for comfort, aesthetics or traction reasons. Just be aware you absolve liability from the manufacturer (BMW) and you become liable, if you go outside of what was homologated by the manufacturer. It is not necessarily illegal to do so, but your insurance could be voided if you do not declare any modifications.

 

[Silverstar]

What;s the view on adjusting to slightly different tyre widths/profiles to OEM on 19" wheels? Any benefit/disadvantage?

That's a bigger can of worms than the RFT issue, there are many who have changed widths or profile for comfort, aesthetics or traction reasons. Just be aware you absolve liability from the manufacturer (BMW) and you become liable, if you go outside of what was homologated by the manufacturer. It is not necessarily illegal to do so, but your insurance could be voided if you do not declare any modifications.

Amazing how much you can mod your car in the UK without any real headaches apart from informing your insurance company. Here almost all mods have to be homologated and pass a separate ITV (MOT) inspection for it to be legal, this can get quite expensive. Tyres have to be one of the sizes stipulated by the manufacturer any deviation and it won't pass the ITV.

 

[WesthillDave]

Hi
I once put a pair of new rear tyres on a 911, different manufacturer than the fronts, but with a lovely tread pattern! The car was terrible to drive, wouldn`t drive in a straight line and always correcting, cornering no better.
Changed the fronts to the same manufacturer and tread pattern...perfect!
My own E89 has four Michelin Pilot Sport tyres and it is a delight to drive. Dead straight, hands off, and corners on rails! A firm but comfortable drive. Hope this helps.

 

[N4LLY]

I ran run flats to the point of MOT failure, so had quit some time with disapointment re handling, tram lining, harshness etc.

The swop to michealin PS4's was an immediate transformation and most excellent

Just my experience.

 

[IanzZ4]

Thanks everyone. Please keep the opinions coming. There’s a picture developing here and it’s not looking good for the current tyre setup!

As I said earlier I’m going to have a top down (pardon the pun) check by the Indy BMW workshop Monday. If that shows all good then it’s off to Black Circles to buy a set of standard Michelin ps5 boots. £576 to deliver the fun the car promises to give over the next few years is acceptable.

Will post results next week.

Best regards

Ian

 

[Pondy]

£576 to deliver the fun for car promises to give over the next few years is acceptable.

Will post results next week.

Best regards

Ian

When you get it sorted, you will find they are really good little cars to drive.

 

[Busterboo]

It occurred to me the week I bought my Z4 six and a half years ago that the E89 would have been commercially more successful if (1) BMW hadn't put silly numbers on it - not least my 35is that's 3 litres and not 3.5 - and (2) had put decent tyres on it and not the Bridgestone runflats that scared me when they tramlined the first time I drove the car at speed.

Did nobody at the factory ever have to describe the models to a journalist? Was there no feedback from authorised dealers? And did BMW never test-drive the cars it was making?

Strange, really.

 

[sars]

When I test drove the e89 in 2010, I very nearly didn't buy one because the test car had 19" alloys and RFT and it really was an appalling combination of road noise and jittery drive. In the end I opted for the standard square 17" with 225/45R17 RFT and the ride and handling was great. After the first winter, I relegated the 17" wheels to winter tyres and plumbed for a set of BBS alloys, again with a square 18" with 225/40R18 Goodyear Eagle F1's and the ride was similar.

 

[RMB]

I test drove a 35i on standard fit runflats once, and never again. It was awful. Tramlining, harsh ride etc etc. Plus it kills the wheels.

Had an E82 on REO50 runflats and ditched them for MPS4 and it absolutely transformed the car plus significantly cheaper too!

This is a no brainer.

 

[Jembo]

Imagine u paid quite a few £ 000’s for your fancy.

Considering just 4 modest patches of rubber keep it away from the scrapyard, am sure the best suggestion made by 99% of the above for premium rubber has to be the one you start with.

The cost of new premium rubber will probably also be a lot less than you’ll loose dealing with the aftermath of an undervalued insurance claim & their subsequent years extra premium getting back what they forked out

 

[Pondy]

The cost of new premium rubber will probably also be a lot less than you’ll loose dealing with the aftermath of an undervalued insurance claim & their subsequent years extra premium getting back what they forked out

Non runflats are a 'modification' as far as insurance is concerned. If you don't inform them they won't pay a penny.

I can't find any evidence of 'cheap' or runflat tyres contributing to any accidents in the UK. The 'ditch finders' phrase is common on car forums due purely to 'tyre snobbery' IMHO.

 

[Jembo]

The cost of new premium rubber will probably also be a lot less than you’ll loose dealing with the aftermath of an undervalued insurance claim & their subsequent years extra premium getting back what they forked out

Non runflats are a 'modification' as far as insurance is concerned. If you don't inform them they won't pay a penny.

Depends which Ins Company

When I asked LV on my old 3.0, had it confirmed in writing provided were all same type, a decent brand & good tread, NRF’s wouldn’t be an issue.

Same went for using winter tyres - not an issue provided using BMW alloys available on the model

What handler said they didn’t like was mixtures & ditchers (cheap poo on a performance car), that’s when they got picky.

OP’s got a rare old mix