[michael3011preston]

Good evening guys!

I recently replaced the rear tyres on my BMW 318i E90 as the rears were very low. I didn't want to purchase run flats so went for the Uniroyal Rainsport 3.
They are 225/45/17 - the same as what were on before.
I've noticed there's a feeling as though it's windy, with the car moving a lot more than before.

I've had the tyres on 1 week, and granted the roads have been snowy, but that's all been gone for the last 4 days. When I was driving at 70 mph on the motorway today it felt as though I was constantly correcting the car.

Does anyone have any idea what it might be?
I know new tyres feel different, but I wanted to check this was "normalish" for new tyres. They were fitted at ATS (£30 for 2 tyres).

Any advice would be greatly appreciated!

Thanks,
Michael

[mob17]

Are the tires on the right side? Pretty unlikely they aren't, but it should say outside or have an arrow pointing forwards on the outside of the tires.

What tires have you got on the front? Sometimes having completely different tread patterns can cause issues, and i know the rainsports have quite a distinct pattern.

[michael3011preston]

I'll double check; I'm quite sure they are..
I've the Bridgestone on the front, with about 3mm - so may have to look to replace sooner rather than wear them out naturally.

[simmo1985]

When i changed from runflats to none runflats just on the rear like you have i got the same sensation. Driving along and it'd feel like car was getting pushed sideways a bit at the rear, only had it on 70mph plus speeds though.

[alex-qts]

Originally Posted by michael3011preston

Good evening guys!

I recently replaced the rear tyres on my BMW 318i E90 as the rears were very low. I didn't want to purchase run flats so went for the Uniroyal Rainsport 3.
They are 225/45/17 - the same as what were on before.
I've noticed there's a feeling as though it's windy, with the car moving a lot more than before.

I've had the tyres on 1 week, and granted the roads have been snowy, but that's all been gone for the last 4 days. When I was driving at 70 mph on the motorway today it felt as though I was constantly correcting the car.

Does anyone have any idea what it might be?
I know new tyres feel different, but I wanted to check this was "normalish" for new tyres. They were fitted at ATS (£30 for 2 tyres).

Any advice would be greatly appreciated!

Thanks,
Michael

With both BMW's that I have had, the tyre combinations front vs back has made a night & day difference. Also both times I have gone rear runflat to non runflat followed by front runflat -> non runflat. The driving miles while having runflats on the front and non-runflats on the back was very uneasy, and I lacked confidence in the handling of the car. As soon as the same brand & model tyre was fitted to the front, the issues mostly went away!

I have just fitted super sports all round, and after having different brands on each axle, its almost perfect now. For some reason BMW's seem really fussy about tyre setups / pressures.

Did you have runflats on the rear before? If so it's also worth considering that runflats have a sharper feel to them due to stiffer sidewalls, when changing to non-runflat the turn-in and overall response of the tyre can seem slower (due to the softer sidewalls until you get used to it) I did notice this when moving away from RFT's.

Might also be worth checking the tyre pressures as that can also make a huge difference to the handling characteristics / stability.

[michael3011preston]

Thanks for your comments. I'll double check tyre pressures - I presume these are as OEM specs with no change due no NRFT?

Back to Camskill next month again.. they'll be doing well of me!

[alex-qts]

Originally Posted by michael3011preston

Thanks for your comments. I'll double check tyre pressures - I presume these are as OEM specs with no change due no NRFT?

Back to Camskill next month again.. they'll be doing well of me!

Yeah don't tell me, Iv'e had quite a few expensive mistakes with tyres recently and learned the hard way!

Yes I would start with the OEM specs, and experiment around that to see what works best for you. I found the handling was awful at certain pressures, but really improved around the stock figures. (Didn't help me that the tyre pump at the local garage was totally out of calibration! Took me a while to figure that one out...)

I am running the OEM pressures (36 front 39 rear for 19" rims) at the moment on non RFT, and they feel quite good, I will have a look at the wear and might change the pressure a bit if needed.

[Pacman83]

Great tyres those Rainsport 3's, I've had them before and they were great. Had absolutely no issues with them, so I'd rule out the actual tyre for the complaint.

[michael3011preston]

Update: I amended the tyre pressure to the OEM specs - the fronts were overinflated by about 0.4 bar, and the rears were 0.2 under... despite some K noob beeping at me for using the air for as long as was required... in a dilapidated old van.
I gave the car a quick burst on the dual carriageway home and it instantly felt lighter steering and more stable. Will test it out tomorrow on the run to work - 20 mile drive - M65 (quiet motorway) and Grane Road - anyone from the NW will know what a road it is when there's nobody else on it...FUN!

Thank you everyone for your advice - much appreciated!

[michael3011preston]

Further update - accelerated quickly up to 70mph and it felt a little "snakey". The tyre pressure are correct and the tyres are on the right way... Going to check alignment next month, unless there are any other options to check.

[MattOz]

Good to hear you've had a semi-result with the pressures. You will find that new tyres move about due to their very nature. Taller tread blocks with newer, less aged rubber, will result in the tyre moving about more. You may find that over a 4-6 week period they will settle down a bit.

[JazzMan2001]

Put the wheels with new tyres on the front, old one on the rear (Assuming they are the same size all round). When I had 225/45/R17's all round on my E46 new tyres on the back really screwed with the steering feel. Swapped them round at it was fine. Worth a shot as it's easy to do

[Jase 320d]

Non runflats are far superior to run flats

It is not recommended to use run flats on one axle and non run flats on the other.

Keep all 4 tyres the same and you'll enter a new world of road holding / comfort


Kill the rft!!

[AWSAWS]

Keep the pressure high without exceeding the max stated pressure op so the sidewalls remain firm like the runflats. The weaker sidewalls are probably why the car feels a bit like jelly.

[HighlandPete]

Mixing completely different tyre characteristics, front and rear, is never going to make for a balanced chassis.

As has been mentioned, it is not advised to mix RFTs with non run-flats, even axle wise. There can also be insurance implications.

Playing with high tyre pressures is not the real answer, could build in other strange characteristics, possibly even more dangerous at the limits.

Changing the front tyres is the proper solution. OP says they are ~3mm, so at a depth many BMW drivers will be changing. At this time of the year, a good idea anyway.

HighlandPete

[alex-qts]

Originally Posted by HighlandPete

Mixing completely different tyre characteristics, front and rear, is never going to make for a balanced chassis.

As has been mentioned, it is not advised to mix RFTs with non run-flats, even axle wise. There can also be insurance implications.

Playing with high tyre pressures is not the real answer, could build in other strange characteristics, possibly even more dangerous at the limits.

Changing the front tyres is the proper solution. OP says they are ~3mm, so at a depth many BMW drivers will be changing. At this time of the year, a good idea anyway.

HighlandPete

As said before, this is what sorted my handling problems for me. well 95% of it anyway.

[AWSAWS]

I'm only advising to raise tyre pressures to their safe upper capability. There are many BMW drivers who have felt the added pressure reduces roll thanks to stiffening the side walls. Something the run flats have built in by design.

[un1eash]

I fitted rainsport 3's to my old Celica and it felt similar to what you experienced, over time they got a lot better though and became more stable and gave the levels of grip I expected from them. Great tyres for wet conditions and I'll no doult go with them when I need new ones.