BMW X4 - Changing from Pirelli P Zero Run Flats

[PhilGibson]

Hi,

I am looking for some advice if possible. I have just purchased a BMW X4 Xdrive Xline 2017. and it has come with Pirelli P Zero run flats. I test drove the car and found it to be relatively acceptable in ride quality, however over the weekend I took it on a much longer drive fully loaded with 4 passengers and luggage in the boot.

The ride quality was awful felt all bumps and pot holes, the feedback through the steering and cabin was rough. My previous car was a BMW 320D M Sport, and this came with run flats which I switched out straight away.

Do you feel switching out from run flats to normal tyres will improve the ride comfort? I am used to the suspension being a little on the firm side due to my previous car being M Sport. This is also the first larger BMW I have owned so I am not sure if it is just a characteristic of the car?

The tyres are
Front - 245 / 45 / R19
Back - 275 / 40 / R19

Thanks.

[Smuler]

Did you adjust tyre pressures for the extra load ?
RFTs have improved , but on various cars I drive they are usually worse like for like.

I had a smaller SUV , went non RFT but also 18 inch wheels and adaptive suspension. That “trio” made for great comfort.

I’d bet on an improvement if you go non RFT but maybe consider a change of wheels to 18s ?
But in any event with a XDrive stick with * marked (means BMW approved) tyres.

[PhilGibson]

I took it out for a drive earlier with no passengers and luggage, and the ride quality on clean tarmac of the motorway is fine. As soon as I travelled on an uneven A or B road you could feel every imperfection through the car and cabin. I am going to try and reduce the tire pressure slightly tomorrow see if it makes a difference, otherwise I think it is either non run flat tyres and / or smaller rims.

Does it make a difference having a much wider tyre at the back end of the car?

[Earthdweller]

I have an X3 Xline and run 18’s and it’s perfectly fine .. mine doesn’t have sports suspension, which yours shouldn’t have either

I’d suggest as above sticking with BMW * marked tyres as other tyres can “allegedly” play havoc with the 4wd system

You can go as small as 17” but I found the 18”s the best compromise

I personally found the 19”s and 20”s too brittle for me .. hence why I ordered the Xline as I couldn’t get an MSport with 18’s

My winter set .. also 18’s provide a lovely soft ride but it loses its crispness

Genuine Sets can be picked up on eBay for about £500 or so

[Pica-Pica]

I find Pirelli run flats are fine on 19”on a 66 plate 335d. However, venture further away from North Wales and the potholes and broken roads in Southern England and Scotland are terrible. I am going down a rim size to 18”. The run flats are not the main issue for me.

[Earthdweller]

I don’t think it looks too bad on 18’s

[bunchofkeys]

As mentioned above, i echo the advice of using BMW * marked tyres, when you have an X-drive vehicle.
I personally tried to move over to non * tyres of the same size, weight rating ect, which only caused havoc with the transfer case; until i moved back over to BMW * tyres.

[mekondelta]

Just an echo.... F25 X3 + 18"s + PZero's + non M-Sport suspension is a comfortable ride. Also harder to kerb the wheels with 18"s, a definite plus!

[PhilGibson]

Thanks all, will take on the advice. Moved my tyre pressure down slightly this morning and it appears to have improved the ride quality will test more tonight.

[PhilGibson]

Hi. Another question. My wheels are 19 inch, so do you think it is worth moving down to 18 inch alloys? My tyre width is off set with 245 front 275 back. If I get smaller alloys do I need to consider this?

I am not sure what configuration to go for to improve the comfort the most.

Remove run flats and fit the same tyre size etc.
Or
Remove alloys fit 18 inch. Put on non run flat tyres.

I just want to make one change that makes the most difference.

[gizlaroc]

I went from 17" run flats on the X3 to 19" non run flats, the 17" run flats were terrible, the 19" non run flats were super, super comfy. If anything you could argue on SE suspension it was a little too soft, but I liked it.

I bought an SE F11 to get it to be super comfy, so went with 17" wheels again, with the aim to put on some 67db class A non run flat tyres to make it really comfy again, it has Goodyear Excellence run flats on at the moment, and to be fair they have been fine, but they are now down to around 4.5mm and starting to feel crashy. Not sure if it is due to wear or ageing.


I don't think it makes much difference what wheel size you have with run flats, it is the sidewall that is so hard, going smaller just means you have more of it.



When I went 19" on the X3, I dropped down a width, this helped the handling no end imho.
Obviously, make sure you go up a ratio if you do that.

[smashy]

I reckon size of the wheels is a major problem. My son in law works at Honda ,he says all the complaints about the ride come with 19 inch wheels attached .

[gizlaroc]

smashy said:

I reckon size of the wheels is a major problem. My son in law works at Honda ,he says all the complaints about the ride come with 19 inch wheels attached .

Sort of, low profile is a problem, not size of wheel as such, but do agree we are putting on too big a wheel for the car.

The 19" Honda Type R has a 30 profile on a tyre that is only 245 anyway, that is only 73mm of sidewall.

The X3 is 245.50.19, so 122mm of sidewall. Stick the 18s on and you get 135mm of sidewall. Go to 20" and you get 125mm of sidewall, hence you may as well go 20 if you are not going 18.

[Pica-Pica]

On my F30 335d x-drive, I have just changed my 19” 442M wheels with Pirelli run-flats, down to 18” 398s with Goodyear Efficient Grip (still run-flats, still a staggered set-up) Initial comments.
Appearance: well apart from brand-new, I believe they look much better. Funnily enough the whole wheel and tyre assembly looks bigger, and the wheel, strangely looks bigger too. I guess that is the design style.
Ride: certainly improved in both ride comfort and most noticeably noise.
Handling: new tyres, so not pushed them yet. I sense the understeer has been reduced a little, so that is a plus. A slight more roll on turn in, but acceptable. On a slightly uneven A road, I did experience some lateral head toss, but maybe I was especially looking for these sort of things, and maybe that occurred with the 19”. Early days yet.
I will clean up the 19” and probably sell them.

[gizlaroc]

That 398 wheel is the lightest wheel BMW make, that will make a huge difference to how well it rides too.

I really want a set of orbit grey, fronts all round, for my F11.

[soupdragon1]

On our X6 - went from run flats to regular tyres and made a huge difference. Bought one of those tyre inflator repair kits for about £30 (the foam that goes into the tyre can be washed out, unlike previous versions) and obviously, you need that kit with non run flats, otherwise you're stranded without a spare wheel.

The ride is night and day more comfortable and quieter. The X6 is very crashy over poor road surfaces and while you do give up a bit of steering precision in comparison, it just makes the drive more enjoyable overall once the non run flats go on. Should have done it years ago when we initially got the car. We've been driving around all this time, spilling coffee and losing all the change from our pockets for the last 3 years

[smashy]

On a tangent my car F30 30d 18 inch started with Conti runflats a really awful ride got rid after 6 weeks (the se shocks and springs went first but thats another story) put on Michelin PS3 normal and all good. 3 years on thought I was handing car back and end of life tyres decided to risk Run Flats again

Did a massive amount of forum and website research and went Goodyear F1 assymetric 3 with a lot of trepidation put the 4 on

Thankfully I chose the right ones .They are really good infact they seem better than the Michelin normals to me in some ways a touch more feel if you will. but not crashy and no howling on certain roads

I would not bother going back to normal to be fair

[PhilGibson]

Thanks for all the advice. Took the decision getting Michelin primacy 3 front and Yokohama advan sport back. Both non run flat but with bmw fitment. Really hope it makes a difference.

[twokcc]

PhilGibson said:

Thanks for all the advice. Took the decision getting Michelin primacy 3 front and Yokohama advan sport back. Both non run flat but with bmw fitment. Really hope it makes a difference.

From my own experience but that sounds like a recipe for disaster mixing trye brands.Before Bmw went 4 wheel drive huge amoun of complaints (tramlning-skiittishness etc)re cars with mixed tyres.
Get same brand for all 4 tyres found Goodear Eagle F1 non runflast considerablely impoved ride on 3 litre SE E91. But best so far for ride comort have been Michelin PS 4's. Fiited to R56 Cooper S to replace other 17" non runflats and considerable improved ride making it even better than 16 " with Michelin energyy tyres.(non runflat).

[PhilGibson]

Dammit just ordered them. It's really hard to find a matching pair of non run flat because of the tyre off set. The 275 40 r19 don't have many options.