What brand are the current run flats C?
I drive a BMW 1 series E88 120D
It uses run flat tyres which are 245/35/R18 88Y
Im on my 5th run flat this year.
first 2 I replaced as they had blebs on the sidewall probably from potholes. Both front tyres. August I think this year.
on a drive down to Cornwall one went on the M5 after a judder on the road.. turns out it had fractured an alloy that I had to get welded. rear tyre
while I was in the tyre place they noticed another bleb on the other rear tyre so I replaced both at the same time. This was 3 weeks ago in oct.
Driving back from Scotland on Monday, tyre pressure warning light on the dash again, flat rear tyre, 3 weeks old. No sign of why it may have blown, no puncture to be found, no fracture in alloy that could explain why it suddenly went but it did.
Runflats have now reached peak doing my t*ts and wallet in!
Ive spent close to 1.5k on them since summer which includes 5 new ones and an alloy repair.
It seems like the tiniest bump or pothole is killing them and I do most of my driving over country roads which are the worst.
Next time one goes which im assuming will be next week im going to replace the run flats with standard tyres.
Can anyone mechanicky advice on which standard tyre size would be best to use on an E88?
The run flats ive got currently have a really low profile and no cushioning. So id be happy to use a deeper tyre, so long as it fits under the wheel arch without the risk of clipping over speed bumps etc.
garbage guy said I should have bigger on front and smaller on rear, I dont at the minute they're all the same size.
I dont know a lot about tyres and any advice would be appreciated!
What brand are the current run flats C?
When you look long into an abyss, the abyss looks long into you.........
I hate the wretched Run Flats on both my 5 series which I bought at 18 months I got rid, such a better ride they always seemed like they would breakaway on a fast corner. I swapped them over on my Z4 it’s was a different car afterwards.
They're a mix, Bridgestone on back and Pirelli front.
Not sure which variants but will go look
Mixed as I had to get replacements at 2 diff places and had to go with what they had in.
One was an indy and the other was national tyres (the Bridgestones)
I never seemed to wear out any goodyear OEM spec run flats out in my f20. The side walls would fail way before I hit the wear indicator. Ditched them in the end
Tyres are normally staggered front to back unless on winters.
Replace will the same size you have now. Costco are normally good for a full set.
Last edited by Middo; 23rd November 2022 at 19:35.
It should be relatively straightforward to find the correct sizes for your particular model, but you can always join a forum and ask the question.
A lot of BMW's do use a staggered set-up, but it does depend on the model and wheel sizes.
RFTs are particularly horrible (as you know!), but are also arguably worse than standard tyres in the cold and wet.
I would't hesitate to change to standard tyres, but would recommend keeping a 12v compressor and can of tyre weld in the car to deal with a puncture situation (the tyre weld should give you the same distance as a deflated run-flat, but only use as a last resort if a re-inflation doesn't hold for long enough).
What’s the width of the wheels (not the width of the tyres), should be something like 8.5 or 9. The rears maybe wider than the front and it’s unlikely the front should be wider.
The tyres you have got on at the moment seem very wide and unlikely to be what was supplied originally, unless the wheels have been changed.
Celia I suggest you pop into your nearest local indie and ask for a cost to change. They will advise sizes and profile that will look best in your wheel arches. Also ask about the tyre pressure sensors working with normal tubeless tyres, just to be safe. From my knowledge of run flats the ride of your car will be transformed in a positive manner when you switch to tubeless.
My last car ( bmw) was run flat and the best advice I got after replacing a few in sucess ion was the get rid and go with standard tyres. Will cost a little more to swap but return is fairly quick if you’re prone to issues.
I think thats going to be the way forward, I'll go find one on the weekend.
Im not planning on changing til one goes again as im still sore from the last raft of tyre replacements.
Was going to make a note on my phone of what to change to in advance so im not scrabbling about trying to google the next time im in the situation.
Bloody things.
have a look at https://www.wheel-size.com/size/bmw/...-120d-eudm-174
It does look like the front and rear tyres should be different sizes - have you checked the handbook, or inside the door jamb or inside the fuel filler flap as tyre sizes and pressures are often listed there.
The link above is for 2011 models, you should be able to find other years listed in the link below
https://www.wheel-size.com/size/bmw/1-series/
Last edited by catflem; 23rd November 2022 at 15:29.
That's the way to go. I had a 1 series with run flats - had no issues with flats but they did find every grove in the road and tend to keep the car in it. I switched to normal Bridgestone Turanza's and the car handled much better. Since then I've had a 3 series and an X1, neither have had runflats. BMW provide the electric pump and a bottle of fluid –*which I've never had to use.
It does look at though you are running wider than standard at the front.
Suggests original spec was 215/40/18 on the front and 245/35/18 on the rear with a slightly wider alloy (8.5j vs 7.5j on the front). So perhaps if you weren’t the first owner they increased the front width.
If you wanted a smoother ride then ditching the awful run flats is a great starting point. As Hilly said, in the Z4 it transforms the car (and the M division never put runflats on the Z4M).
I have changed them on every BMW / Mini I have had and never been disappointed with the transformation.
You mention fitting a deeper profile tyre. Usually to get any difference you would need to drop the alloy size down to 17in and then fit a tyre with greater side wall. It needs calculating to ensure the rolling circumference is the same / similar.
You will certainly find that non runflats are significantly cheaper and more compliant on the road too. It won’t stop a bulge happening if you hit a pothole but even the 18in wheels you have currently will become more comfortable.
This 100%
Where are you based Celia? Am sure one of us can help recommend a decent place to visit and chat about the options with someone who knows their onions.
Was about to add I've run two 5-series for the past 6 years (3 yrs on each lease), the 1st with runflats, the 2nd with normal tyres. No excessive punctures with either model (1-2 tyre replacements over each 3yr lease). I don't actually notice the difference in ride between the two, but that's likely me having no driver feeling whatsoever (given most forum owner feedback is RFs kill the ride, and your spine).
The approved tyre sizes should be on a sticker somewhere on the car - either the driver's door pillar or maybe on the fuel flap & once you have that information you can start looking at alternatives - the size doesn't change between run flat & standard tyres. It get much trickier if you want to change the size of the wheels, say from 18" to 17" as that is where you need to be careful selecting the right size to keep the rolling radius as close to original as possible. Going to a 17" (or even 16") wheel will give better ride quality & more protection from potholes.
That’s correct as long as someone hasn’t changed the wheels.
245/35/R18 88Y Seem very wide for the fronts on that car and if they are standard wheels then they are too wide.
https://www.tyres-pneus-online.co.uk...ce-advice.html
Last edited by craig1912; 23rd November 2022 at 17:11.
Im gonna have to go take a torch to the petrol cap and door pillar (altho ive never noticed any pillar plate on there)
Going by that, you should perhaps have different rim sizes front and rear. (little pictures of front of car and back of car by the sizes)
7.5j width front with 215/40x18 tyres
8.5j width rear with 245/35x18 . So worth checking that first.
This online calculator will give you nearest sized matches. Might be you need 2 different sizes. https://www.oponeo.co.uk/tools/tyre-...nativeTireTool
Of course someone might have changed the tyres for wider ones for a 'better' look. Perhaps yours had 7.5j width rims all round originally. Does happen so checking the wheel sizes first might be preferable, its often stamped on the rims.
Last edited by oldoakknives; 23rd November 2022 at 17:31.
Started out with nothing. Still have most of it left.
My wife and I both have BMWs (5series and 1 series). My previous one was also a 5 series.
First thing I did was to ditch the FR.
It allowed me to fit Cross climate + on both cars.
The difference in comfort, and feel in the wet -not to mention sleet- is phenomenal.
The downside is that you either buy the spare wheel and keep it in the boot, or take your chances with one of these puncture repair kits. It will take you to the nearest tyre fitter but you may not be flavour of the months when they change your tyre.
'Against stupidity, the gods themselves struggle in vain' - Schiller.
Hi
Whatever tyre/size you decide I would recommend checking with your insurance if you choose tyres not listed as an option from the manufacturer for your particular vehicle........
Recomended on many Car Forums, and thus avoid heart-ache should an 'unexpected-unexpected' happen and your insurer picks up the change and doesnt want to be helpful.
L-K
I have had BMWs as company cars for decades, and despite doing about 20,000 miles a year , generally, have had no issues with any which were fitted with run flats, the ride night be a bit firmer but that's about it , for me. It might be that the cars were changed avery 6 months so I was always on "fresh" tyres but I must have had several pothole encounters . I imagine it is largely a bit of bad luck, shame it works out so costly.
Two things:
First, the manufacturer tyre specifications are noted on a black sticker on the drivers door wall (visible when door is open). If your car is on its factory wheels, these are the tyre specifications you can fit (my understanding is that these won’t be notifiable for insurance purposes).
Second, I had sidewall damage on two consecutive sets of RFTs specified by the BMW dealer, until I realised they had erred and that my car needed XL (extra load) specification (per black sticker). No problems since. Unlikely that a 120 needs XLs, but worth checking and if they’re a specified option I think it would sort you out.
Good luck!
245 is the wrong width for the front of a 120.
Soz C, but if you keep damaging the tyre wall then a non run flat will not fix the issue!.
When you look long into an abyss, the abyss looks long into you.........
Surely that many punctures demonstrates why runflats are a good idea? I’m not convinced that the RFTs were the cause of these punctures and with regular tyres any of these pothole incidents could have led to a blowout and a serious accident.
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Not really. The difference between a RFT and a normal tyre is that after a puncture you need to change the wheel there and then (and yes, it can be dangerous; that's why you have RAC or AA) with the latter instead of continuing at reduced speed to the next garage. That comes at the expense of limited choice of tyres and significantly harsher ride.
Blowouts are rare with radial tyres, and some RFT have been destroyed by a pothole. I'd rather have a tyre chosen for its roadholding properties in the sort of weather I am in, rather than its resistance to blowout as I am statistically more likely to need the former.
'Against stupidity, the gods themselves struggle in vain' - Schiller.
Why do most top end German car manufacturers supply RFT's as standard?
I understand a cost benefit to some degree, but why do those that change to normal tyres think that they know better than companies that spend billions on R&D?
I had a Merc GLC Coupe until last year. It was on runflats for 22months out of the two years I had it and the already harsh ride on that model was bordering on intolerable for all that time.
Two months before I gave it back it was switched to standard tyres. My god, it was like a completely different car. For those final two months it was actually comfortable.
So clever my foot fell off.
I think it’s both a cost and convenience issue. With runflats you don’t need to supply a can of goo and a compressor, or need to make the space to carry them in. As an aside, In my cars whenever I look at them the can of goo is always past it’s best before date. The convenience issue speaks for itself. TPW light comes on, you have a quick squint to see the tyre is still attached to the rim, and then drive to the nearest Quick Fit or similar. No scrabbling around in the mud at the side of the road.
I'm not so sure I would blame the run flats for the punctures and bulges.
Potholes in the UK are commonplace and a nightmare. It's not uncommon for alloy wheels to suffer damage and deform, leading to difficulties with tyres maintaining pressure. Are your wheels the originals, and is there any history of comparable BMW wheels failing. It might be worth considering alternative wheels.
As everyone has mentioned, size wise buy the tyres referenced in your car's service booklet.