[Monger007]

At present I have the following RFT on my 320D M Sport. These tires are way to hard for my location, but might be ok if you have grade A black top roads.

Front 225 x 40 x 18
Rear 255 x 35 x 18

These tires are in my opinion not suitable for this car, so I plan at some point to fit non RFT and was looking at Pilot Sport 3 that are available at my location. Due to the crap roads I am thinking of perhaps fitting the following. Just checking if there would be any issues ?

Any input would be a big help.

Front 225 x 45 x 18
Rear 255 40 x 18

[Phil325i]

With that higher profile your overall wheel diameter will increase by about 3.5%, so at 70mph your speedometer will be reading 73mph. Why not stay with the OEM size? You'll find a great improvement with non-runflats even if you don't up-size...

[Jase 320d]

Stick with original sizes

Non rft compared to rft's is amazing

My standard wheels were 16" rft's and i would say my 18's with non rft's ride more comfortably


Rft's are the work of the devil

[E92Dan]

Originally Posted by Jase 320d

Stick with original sizes

Non rft compared to rft's is amazing

My standard wheels were 16" rft's and i would say my 18's with non rft's ride more comfortably


Rft's are the work of the devil

Ha ha that's very true!

[windymissile]

Ditch the runflats. Night and day difference.

Spend the money you will save on a can of tyre weld.

WM

[Monger007]

Originally Posted by Phil325i

With that higher profile your overall wheel diameter will increase by about 3.5%, so at 70mph your speedometer will be reading 73mph. Why not stay with the OEM size? You'll find a great improvement with non-runflats even if you don't up-size...

Thanks for the information provided
The upsize was only just an idea, as per the feed back I will go ahead and stay with the OEM size.

Also just checking on the following regarding width, would it be possible to move up one size with the non RFT.

Front 235 x 40 x 18
Rear 265 x 35 x 18

[Phil325i]

Depends om the offset of your wheels. You could get some rubbing issues with the wider treads...

[Monger007]

Originally Posted by Phil325i

Depends om the offset of your wheels. You could get some rubbing issues with the wider treads...

The offset of the rims are

Front 34
Rear 37

[windymissile]

Originally Posted by Monger007

Thanks for the information provided
The upsize was only just an idea, as per the feed back I will go ahead and stay with the OEM size.

Also just checking on the following regarding width, would it be possible to move up one size with the non RFT.

Front 235 x 40 x 18
Rear 265 x 35 x 18

I have these sizes on my E90 winters. No rubbing at all.

WM

[Tonyblade]

Hi I've got these sizes on mine too, does anyone know if I change to non run flats will I get messages on the I drive screen warning of pressure loss? I believe there's sensors in the runflats that send signals to the cars brain. Or am I totally wrong? Thanks

[Ess]

Originally Posted by Tonyblade

Hi I've got these sizes on mine too, does anyone know if I change to non run flats will I get messages on the I drive screen warning of pressure loss? I believe there's sensors in the runflats that send signals to the cars brain. Or am I totally wrong? Thanks

I don't believe that's the case, but even if it is you can reset it (sorry, can't remember how but I'm sure you'll find it if you search!).

I just recently moved to non-RFT and am really surprised at the difference it made when going over imperfections in the road. I wasn't convinced, but now that I've experienced both I would recommend it.

[Tonyblade]

Thanks ess
Think I'll have to do it then . I have the nav pro widescreen and when the warning message comes up I loose a half inch off the top of the screen when pressure loss is detected. It stays like this until I reset it. As long as I can still reset it when using non runflats I'd be happy.

[Ess]

Originally Posted by Tonyblade

Thanks ess
Think I'll have to do it then . I have the nav pro widescreen and when the warning message comes up I loose a half inch off the top of the screen when pressure loss is detected. It stays like this until I reset it. As long as I can still reset it when using non runflats I'd be happy.

I've no doubts you will be able to - many people switch to non-runflat, and I've never heard of anyone getting tyre pressure issues as a result. I'm not entirely sure how the pressure sensor works on our cars, but I'm quite sure it's nothing to do with the tyre itself. Don't worry!

[Jase 320d]

Tyre pressure is off abs / wheel speed sensor

Has nothing to do with the tyre setup whatsoever

[themanthatcan]

Originally Posted by Jase 320d

Tyre pressure is off abs / wheel speed sensor

Has nothing to do with the tyre setup whatsoever

Yup exactly, the car uses the ABS sensors to detect if one wheel is rotating more often than the others.

As long as you reset the TPMS after changing the tyres (so the car re-learns what your wheels rolling radius is) you won't get any warnings.

[Tonyblade]

Thanks so much guys that's why communities like this are great! Tony.

[zltm089]

265 too wide for oem 18inch wheels...i wanted to go wide too
But restricted by the wheel size

[Monger007]

Originally Posted by zltm089

265 too wide for oem 18inch wheels...i wanted to go wide too
But restricted by the wheel size

I am glad I checked first, as there tires need to be ordered at my location. The boss at the tire shop informed me 255 is the max for the 18 x 8.5j rims

[ChrisN53]

When making the switch to non-RFT's, do the same tyre pressures quoted on the driver side door still apply (assuming the tyre is the same width/profile etc)?

[zltm089]

Originally Posted by Monger007

I am glad I checked first, as there tires need to be ordered at my location. The boss at the tire shop informed me 255 is the max for the 18 x 8.5j rims

The "boss" is correct.... very surprised that he knew!...as most of these tyre shop monkeys haven't got a clue!

you can go 235 for the fronts tho...and actually i think that 235 or even 245 should be std at the front as it improves handling and reduces understeer....

[Jase 320d]

Originally Posted by ChrisN53

When making the switch to non-RFT's, do the same tyre pressures quoted on the driver side door still apply (assuming the tyre is the same width/profile etc)?

38rear 35front for me

[hey joe]

It's always seemed to me to be rather a paradox that these Run Flat Tyres - designed to work at zero pressure (albeit with limited speed and range) - need such relatively high pressures in normal use the rest of the time !!