[MrPogle]

I've only had it a couple of months and it has been pretty windy recently but it seems to need more constant correction on windy motorways than my E90 did. Don't get me wrong, it doesn't feel unsafe or out of control but side winds seem to deflect it more than I am used to. I'm prepared to believe that, because the F10 insulates you from the speed better than the E90, I subconsciously backed off a bit in the wind previously and am not doing so now.

Any body else think the F10 is maybe a bit sensitive or even that the E90 is exceptionally stable?

[B33M3R]

Can't say I ever noticed this? Always felt quite planted to me. Saying that, I don't recall my E90 being susceptible to it? Mk5 Golf Gti though.....

Perhaps worth having your wheel alignment checked. Tyre tread all good? My WRX tracked all over the place when the tread got low, admittedly a 4WD though.

[HighlandPete]

We've had many comments of specific cars needing steering correction in the F10/11 models. But it doesn't apply to all cars.

My F11 is not in that category, steers well and doesn't suffer from tram-lining or the like. In bad cross-winds it is very stable, needs very little correction, if any.

I'd say it is more car specific than a model trait. It would be interesting to know if those who suffer the straight line sensitivities also get cross-wind disturbances. Could be a combination of alignment and wheel sizing/tyre combinations.

[MrPogle]

Thanks for the comments. It is only wind. The car steers and handles beautifully IMHO and doesn't tramline. The tyres are brand new but are winters. I'll be putting summers on at Easter (also brand new) so I'll see if that changes anything. I thought that the steering issues on the F10 were only pre-LCI and only electric PAS but I may have misunderstood.

[AP]

I was on the M40 at the weekend and there was a strong easterly wind which I was certainly aware of at times.
I have reported on these forums before, that certainly with my setup, the steering is very sensitive to conditions. I have a 530d msport with passive msport suspension on 19inch wheels.
A strong crosswind is detectable on this setup although it doesn't cause any issues.

I can only compare my car to my previous E39 msport which was on 18" wheels. that certainly felt more 'planted' on the motorway although it was a stiffer suspension set up that I feel on the F10.(No doubt to compensate for the RFTs)

If I could have a F10 with the E39 steering and suspension I'd be 100% happy with the car but I feel these are 2 areas that let the car down in my opinion. I think the E39 was such a good car (for its time) that anything afterwards had a lot to live up to.

I rarely drive the car in sport mode when the steering weights up a bit at speed so not sure if this helps in any way or not.

[shiner]

My F10 from 2011 was terrible for this. Felt like I was driving on ice when in windy weather conditions. Never had it in any of the three F11's I have owned (520, 530 and 535).

[dockishen]

Hi all,
Had the same problem with my f11 until I put in some stiffer antiroll bars ,
Now it's solid and doesn't feel like a pudding in the wind , especially in the recent storms.

SE spec feels soft as well so don't know of this makes any difference to crosswind movement

And winter tyres are notorious for feeling odd in the wind.

[shiner]

Originally Posted by dockishen

Hi all,
Had the same problem with my f11 until I put in some stiffer antiroll bars ,
Now it's solid and doesn't feel like a pudding in the wind , especially in the recent storms.

SE spec feels soft as well so don't know of this makes any difference to crosswind movement

And winter tyres are notorious for feeling odd in the wind.

I don't think being an SE spec is the issue. My 520 F11 in SE spec was fine has have been both my F11 M Sports.

[martin mustang]

Yep my one is 2011 m kit and certainly feel the winds more than my ex e60, I thought it was down to car weight and of course shape, but reading this tread sound like only specific to a selection of F10, interesting!

[mobilejo]

I was noticing after passing huge lorries that i'd feel the wind hit me and the car would literally roll to the right. I was on 32/33psi. I pumped up the tyres to 36psi all round and it has cured it. Handles better too and isn't any harder.

2012 M Sport with VDC, 19's and RFT's

[HighlandPete]

Originally Posted by mobilejo

I was noticing after passing huge lorries that i'd feel the wind hit me and the car would literally roll to the right. I was on 32/33psi. I pumped up the tyres to 36psi all round and it has cured it. Handles better too and isn't any harder.

2012 M Sport with VDC, 19's and RFT's

Interesting, perhaps other users with a cross-wind problem should experiment with tyre pressure. I wouldn't have that issue anyway, as I always run a slightly higher pressure, as I don't find the lower pressures work for best ride quality, road interference, or tyre life.

[mobilejo]

Originally Posted by HighlandPete

Interesting, perhaps other users with a cross-wind problem should experiment with tyre pressure. I wouldn't have that issue anyway, as I always run a slightly higher pressure, as I don't find the lower pressures work for best ride quality, road interference, or tyre life.

I've noticed the same. It seems counter intuitive but a higher pressure on the run flats actually makes them more comfortable. Handling is naturally better too.

I think perhaps with the lower pressures the tyre is riding more on the outer edge which is where the RFT is hardest. With higher pressures more of the centre area is loaded up and perhaps this part of the tyre is softer.

[HighlandPete]

Originally Posted by mobilejo

I've noticed the same. It seems counter intuitive but a higher pressure on the run flats actually makes them more comfortable. Handling is naturally better too.

I think perhaps with the lower pressures the tyre is riding more on the outer edge which is where the RFT is hardest. With higher pressures more of the centre area is loaded up and perhaps this part of the tyre is softer.

Once I'd got familiar with my 2006 E91 330d, and experienced strange driving characteristics, I had to get my mind inside this RFT issue. Being in R&D, was natural to try and understand why the working envelope was so tight. I checked out lots of run-flat tyre wear, visited a few BMW dealer forecourts and checked the wear patterns, run trips where I checked the pressures for warm up times and working pressures, even run the wheels over plates with ink on the tyres to get the true footprint. Soon realised we have a very tight window for optimum pressure setting.

Many try and soften the ride with running low pressures, similar to how many do with non run-flat tyres, even if bad for the tyres. Just doesn't work with RFTs. As you say, we run on the sidewalls, hence the harder ride, tram-lining and road interference, particularly to the steering. We must run on the crown of the tyre, vertical stiffness is lower over a greater load range, there is more flex to higher shock loads.

I got into conversation with BMW Technical, who actually advised upping the pressures to try and eliminate some of the issues I was experiencing. My personal decision was to up the pressures by ~0.2bar, particularly as I drive many short trips ~12 miles. 12 miles is nothing for warming a RFT in winter time, we don't get anywhere near the working pressure, often no more than 0.05bar above the setting pressure. When we consider the ideal running pressure is not the setting pressure, but the warm working pressure, (0.2 - 0.3bar higher) it is easy to see why many users don't even get into the optimum working pressure range, unless adjusting to a higher cold setting pressure.

Get a rapid ambient temperature drop from the tyre pressure setting temperature, so easy to start feeling the negative characteristics coming through to the driver due to low pressures. Adjust the pressures for the lower ambient temperature and you are back to where it all works best again.