[mike235i]

Greetings all,

I love this car but ride height is too low, cannot park anywhere without the front scraping. The Pirelli runflats have no grip, are noisy and ride rough.

Has anyone tried a 17" wheel with a better tire for all around performance and comfort or am I too old to be asking?

Increased ride height would also be a plus and I do not care about speedo error.

If there is humor in this question I would love to hear it.

Thanks

[XutvJet]

Much of the ride quality issue is with the runflats.

[Zircular]

The Mrs. used to have a 335i xdrive with runflats, and she always blamed the sport suspension for the awful ride. Non-runflats transformed it. I can’t help you with height. I try to park well away from curbing and generally gave up on getting my 6’2” frame into or out of the car gracefully.

[morphomeman]

I bought 17" wheels for my winter tires. Eventually, though, I got tired of the summer tires being chewed up and spat out by our local roads and now use the 17's year round. But I am old, very old.

[Cos270]

I'm running square 245x40 R17's and have no regrets.

[Sportstick]

I long ago switched to 225/45-17 (BBS wheels) and run Michelin PS4S. Car is an excellent balance of performance and comfort. As to ride height, did you buy the car new or did a prior owner modify it? I've not heard of ride height problems with original factory specs.

[atek]

your best bet is to change wheels and tires.

[msej449]

Actually, I think that the runflats get too much of the blame versus the 18" wheels. I have Pirelli S3 runflat 17" winters and Bridgestone S001 runflat 18" summers and have never had a beef with either of them. But a lot of people express unhappiness with runflats so I guess I'll just have to defer to their feedback, especially re the Michelins.

But as @atek said, your best bet is probably to swap to 17" and a better tyre than the Pirellis, which I don't think are well-suited to this car anyway, runflat or goflat.

You've got to maintain the rolling radius, so you can't just put higher-sidewall tires on the same wheel* To get more sidewall, you need to drop wheel diameter to 17". Most people seem to prefer them in terms of ride comfort and pothole resilience. @Sportstick makes a good point that standard BMW ex-factory sizes generally shouldn't leave you with ride height issues. If someone has put on an 'outside-the-envelope' wheel and tyre combination, then in an ideal world, you'd first switch to an 18" standard OE setup and see if that's OK, before making the switch ro 17". But obviously, this may be unrealistic and you're searching for getting any change right first time.

@Mike235i It might be useful to tell us what your current full spec' is in terms of wheel (width x diameter & offset) and tyre (width/aspectratio-diameter) as well as specific type (PZero? P7? etc.).... For example, my OE summer setup is Front: 225/40 R18 92Y on 7.5Jx18, Rear: 245/35 R18 92Y on 8.0Jx18, Bridgestone Potenza S001 RTF * Whilst the winters are 225/45 R17 94V XL on 7Jx17, Pirelli Winter Sottozero S3 RFT *

Also be aware that performance tyres often degrade disproportionately fast below the 4mm (5/32") tread depth point. One test result I've seen saw the tyre add over 2x car lengths extra to the stopping distance at 2mm (1/16") vs 4mm at just 50mph on dry summer tarmac. Other aspects of the tyre's handling can degrade similarly. So some of your unhappiness may be down to simple tyre wear.

* Addendum: here's a diagram to underline the point around transitioning from 18" to 17" - for typical 2 Series tires, the drop gives you 50% extra sidewall. But you have to keep the overall diameter the same.

[dradernh]

Originally Posted by Sportstick

I've not heard of ride height problems with original factory specs.

Parking lot concrete tire stops can be just high enough to cause our cars to scrape. Even before I had my suspension done, when pulling in front-first I'd learned to let the rear-end stick out rather than chance another scrape.

It can really rain here, and the builder poured a high curb in front of my driveway. My 1¼"-lowered car needs a couple of 2X4s placed in front of the curb to ensure the bottom of the bumper cover doesn't scrape. The wife's Mazda 3 occasionally just barely scrapes on it, too. I think my unmodified F22 would have scraped too if we'd been living here before the car was modified.

[Shovelman]

Mine has 17" wheels and base suspension. It rides over bumps better than most other vehicles including Suburban and Outback. Tires don't seem to affect ride so much. Not sure the 'upgrade' to M with 18" wheels is the upgrade for everyone.

[albertw]

My M240i with runflats jostles me over bumps about the same as our RAV4. I have a lot of trouble understanding these recurring complaints about the bumpy ride with runflats.

[Gregoryb01]

I got rid of the run flats. The car drives completely differently, in a good way, including the suspension.

[Sportstick]

Originally Posted by Gregoryb01

I got rid of the run flats. The car drives completely differently, in a good way, including the suspension.

I can relate. This comment regards my 3 Series, but I swapped out the original crappy Pirelli runflats for Michelin Primacy3 ZP, also runflat, and the quality difference in ride and noise was immediate. Even within runflats, it is not difficult to improve on the OEM tires.

[msej449]

Originally Posted by Sportstick

I can relate. This comment regards my 3 Series, but I swapped out the original crappy Pirelli runflats for Michelin Primacy3 ZP, also runflat, and the quality difference in ride and noise was immediate. Even within runflats, it is not difficult to improve on the OEM tires.

+1 This is my point re blaming the OE (Pirelli) runflats for 100% of the problem, when people almost invariably change from runflat>goflat and from Pirelli>something a lot better. And often from worn>new as well. They're chaning x2 if not x3 things at the same time and then saying all the improvement is down to switching to goflats. Not that there isn't a difference, just that for some people, changing from the unsuitable Pirelli RFs to another better-suited premium RF brand produces a substantial improvement by itself.

[morphomeman]

It would be great to do a double-blind experiment, to see if people can actually detect with any reliability the differences between tires. I suspect that the majority of even experienced drivers could not. But when we invest large sums of money in switching, then we will find an improvement, whether it is there or not.

[XutvJet]

Originally Posted by morphomeman

It would be great to do a double-blind experiment, to see if people can actually detect with any reliability the differences between tires. I suspect that the majority of even experienced drivers could not. But when we invest large sums of money in switching, then we will find an improvement, whether it is there or not.

You can definitely tell the difference between run flats and standard tires. Run flats have a far more brittle ride due to their overly thick and less compliant sidewalls. A heavily worn run flat is absolutely terrible in terms of ride quality.

Run flats are just junk. They are WAY more prone to blow outs compared to standard tires. The reason again, those run flat sidewalls. A standard tire can take a far greater impact hit whereas the run flat will likely blow due to the lack of sidewall flexibility. On a standard tire, the rim will often bend before the sidewall gives up.

The run flat days are numbered.

[albertw]

It's probably worth repeating my experience with replacing the front Pirelli runflats with the same model of goflat Pirelli performance allseasons. (Actually the rears wore out prematurely down the centre because the recommended rear tire pressure is much too high. I moved the good fronts to the rear, since the rears are more prone to punctures and put the new goflats on the front.)

There was a tiny improvement in ride harshness from the front, but it was barely detectable and certainly not worth changing tires just to get it. One caveat is that I run 38 psi on the front for a slightly sharper steering response and more even wear across the tread, which possibly might make the goflats harsher without affecting the runflats as much.

I've read all the tire threads and this is the only case of an assessment of the difference between runflats and goflats where the same brand, model and style was used and the runflats were far from worn out. All other claims of big improvements when changing to goflats involve changes in many more variables, making those claims suspect to me.

[morphomeman]

Originally Posted by XutvJet

You can definitely tell the difference between run flats and standard tires.

My point is simply that it would be nice if someone could PROVE assertions like this empirically, rather than repeating them.

I am willing to be convinced either way.