19” down to 18” is it worth bothering?

[Ukrobotman]

Am running on 19” with run-flats, I’m considering 18” alloys and non runflats. Is it worth the expense?
How much difference am I going to feel if I just replace my 19” runflats with non run flats ?

 

[biggles]

Not sure what you have got but on my e89 with non M-Sport suspension I ditched the run flats and also went up one profile from 225/35/19 & 255/30/19 to 225/40/19 & 255/35/19, this transformed the car all round giving visually a better balance of tyre and rim rather than looking like rubber bands! It also filled out the wheel arch gap nicely, there is no rubbing either except for a small patch a couple of inches square on the front of the wheel arch liner at full lock, which I don’t hear but can see it when cleaning, the best bits are how it transformed the ride quality from a harsh and crashie ride where even going over cats eyes wasn’t nice and felt like it would break something! to a pleasant little thud of the tyre over bumps and cats eyes, oh yes and no more cracked rims (296’s) since changing over 3 years ago and the speedo reading is much more accurate as well, it still over reads but only by about 1-2 mph now.

 

[Tyreman]

I would ditch the runflats, it will improve both the ride and handling if you fit a premium product.

If you want to go for 18" I'm sure that there will be a queue of people willing to do a deal with you

 

[mmm-five]

I did it on a Z4MC.

Wasn't on runflats, but the car came on 19" CSLs with Michelin PS2s.

Was very skittish, and not confidence-inspiring to say the least.

Swapped back to OE 18" 224M on PS2s (and more recently PSS) - and have not had an issue in 130,000 miles (no broken springs, bent wheels, etc., either).