E89 rear slippery on wet country roads - Best solution ? Tyres ?

[enuff_zed]

Now I just to figure out a way of removing the grass etc that have dried on the rad and intercooler behind the grille. Hoover attachments won't fit and I don't really want to poke a stick through the gaps in case the soft metal gets damaged.
Maybe an airline at a petrol station?

Won't a hose do it?

[Wigsters]

Std tyres are the answer for sure.
My 5 series was lethal in the wet on any corner. Its the uk's less than smooth roads I think, the tyres just have no 'give' in them. Non run-flat tyres transformed the car completely.

[Fireball]

When changing from RFT to non RFT tyres is it a straight swop size for size ? Or does the side wall aspect / width change? I also have worn Bridgestone run flats on asymmetric 18” inch rims and want to go down non RFT route. Is it a myth that your insurance company need to be told if you make the non RFT change ?

[Pbondar]

When changing from RFT to non RFT tyres is it a straight swop size for size ? Or does the side wall aspect / width change? I also have worn Bridgestone run flats on asymmetric 18” inch rims and want to go down non RFT route. Is it a myth that your insurance company need to be told if you make the non RFT change ?

On 18" rims normal Z4 Forum practice is to swap size for size..

Technically, since the car was not approved for run-flats you should notify your insurance company, others will plead the 5th amendment

[R.E92]

It's a straight swap. No need to mess with tyre sizes. As for tyre pressures, that's more divisive topic than Israel on here but my experience is that you want to lower the pressures a little from what's written on the door jamb.

The knuckle draggers that work in tyre shops / dealerships will often tell you some crock about the wheel not being designed for non-runflat or that the suspension was designed specifically for runflats.

Regarding insurers, I wouldn't bother. Some like to quote small print about deviating from manufacturer specification but the reality is that you are deviating from manufacturer specification by not using BMW screenwash, not using the exact oil BMW recommended or by not having star marked OE versions of the exact tyre that came fitted. In fact a proper pedant would argue that even if you have your car serviced by BMW and they use the new spec Shell Helix rather than the original Mobil oil you should ring your insurers

[Fireball]

Thankyou very much for the replies, I am a great fan of Michelin tyres on my bikes so probably go down the same route for the car. Expensive job for all 4 which will include taking less than half worn fronts off, a few of my work colleagues swapped out run flats on various 3 series cars and all wax lyrical obout the improvement in ride and grip etc.

[mr.tourette]

Ditched the OE run flats and replaced with 4 Vredestein Ultrac Vortis and they're phenomenal in the wet and dry. Got caught in a massive thunderstorm last week and they coped with flooded roads, gravel and rocks washed over the road and not one slip.
Now I just to figure out a way of removing the grass etc that have dried on the rad and intercooler behind the grille. Hoover attachments won't fit and I don't really want to poke a stick through the gaps in case the soft metal gets damaged.
Maybe an airline at a petrol station?

I bought one of these for those kind of jobs.. honestly one of the best tools I have ever bought, bit pricey but performs very well, amazing how many uses you start finding for one once you have it


https://www.amazon.co.uk/XPOWER-Electri ... mcd_asin_0

[flybobbie]

Ditch the shocks, the basic standards are rubbish. Go Bilsteins, i had same problem with traction flashing on country roads, even in the dry.

[mcbutler]

Thanks guys for all the advice. I have just ordered 4 x Michelin Pilot Sport 4 (non runflat), to be fitted on Wed. And you are right, I care much more about not aquaplaning into a tree when the road is slippery, than about dealing with a hypothetical puncture.

I will add a 12V tyre inflator, that's actually great advice, didn't think that was an option.

Good choice, you will love them.

[bluesun89]

For context, I am on 18" wheels and it did cost me 460gbp all-in for the four Pilot Sport 4 order at ATS Euromasters (all quotes online were landing in the 440-500gbp area). Im sure i could have get them a little cheaper if i digged further, but their garage in my area has v high satisfaction rating, and i just want to get it done right.
Also, am sure that's way less than BMW main dealer would have charged me

[Jasonn]

I'm always one to err on the side of caution with insurance, I contacted mine (Hastings) and told them of my intention to change from RFT (when funds permit - thanks COVID! ) they just made a note on the file and confirmed it by email, no cost, just worth it for the peace of mind.

[bluesun89]

Just curious, when changing from RFT to non runflat tyres on a E89), we can still re-initialise sucessfully the Tyre Pressuring indicator, correct ?

(According to the owner manual, they call it "runflat indicator RPA" - but since its a calculation based on anomalies in tyre rotation speeds, rather than a sensor, it shouldnt matter whether or not i am using RFT or normal tyres?)

[enuff_zed]

Just curious, when changing from RFT to non runflat tyres on a E89), we can still re-initialise sucessfully the Tyre Pressuring indicator, correct ?

(According to the owner manual, they call it "runflat indicator RPA" - but since its a calculation based on anomalies in tyre rotation speeds, rather than a sensor, it shouldnt matter whether or not i am using RFT or normal tyres?)

Works perfectly well on mine.
Obviously you need to reset it once you have the new tyres fitted, and if you play around with pressures, you need to reset it to suit those each time too.
Easy to do though.

As an aside, and knowing these things always bring out claim and counter claim, after some experimentation with Goodyear Assy 5s on my 18" rims, I am now running 34psi front and 36psi rear and it suits me fine.

[bluesun89]

Thanks for the advice - I have just had the Pilot Sport 4 (non runflat) put on the Zed today, will try this weekend to see if the grip is better on wet roads.
But yeah i can already feel the difference in comfort on the road bumps..

[brillomaster]

take it easy the first few miles... high performance tyres will likely need to do a couple hundred miles before they perform optimally, they may well be very very slippery when they're fresh on the car!