Not apples to apples, but half the Corvette owners on the planet,
(including me), have swapped out RFTs for non-runflats with no
problem. TPMS still works like a champ, too...

From the Large '08 owner's manual, found on the front page of
this site, I could find nothing that said one must use RFTs...

I did find this legaleze/liabilty dodging/support your Stlr's tire sales
jive, on page 239:

"The right wheels and tires

When mounting new tires or changing over
from summer to winter tires and vice versa,
mount Run-Flat Tires for your own safety. Your
BMW Sports Activity Vehicle Center will be
happy to advise you."

GL,mD

That is the biggest bold faced lie I've ever heard. Wow, people are becoming more and more uninformed, on the product they sell.

He probably was meaning to say that the E70's suspension was specifically designed with the intent of running RFTs, but in no way does that statement mean that a conventional tire of the same dimensions as the RFT won't fit.

Wow.

I think you'll find that you can fit non RFT on the rims designed for RFT but not vice versa.

True. The RFT rims are "hump" rims. They have a second hump on the inside to prevent the deflated tire from sliding off the rim.

Just keep in mind that if you are leasing the car has to go back with RFT's on

I just don't understand the big deal about people complaining how un-comfortable the RFTs are. I have the 19" and they are as comfortable as my 18 non RFT from my E53. Yes, they are expensive but we all chose to drive an expensive car anyway. There's not a price you can pay for safety. I had a tire blow out on my E53 a few years ago driving 80 miles an hour on my way to Vegas. I almost lost control, but was able to pull over without any incident. I would have probably rolled over if that was another SUV. Yes, the E53 did really well on a blowout with non RFT tires but the RFT tires on my E70 gives me peace of mind that I'll have an even better chance of making it out alive when I get a flat tire when driving at such high speed. Just speaking from personal experience and opinion.

Change them and you'll see the difference. It's massive.

To many of us it's not about money or cost of tires. It's about the ride quality.

While blow outs do happen, the odds of a blow out are drastically reduced if the tire is maintained regularly. Check you pressures once a week, and you should never, ever have a blow out.

In addition, I've had horrible experiences with patching RFTs. Tire shops just won't do it anymore. There's too much liability for them to perform a $20 patch, and the process for replacement is no different than if you get a nail in a conventional tire.

Get a nail in a RFT, drive slowly to the tire shop and buy a new tire. Get a nail in a conventional tire, use the BMW roadside mobility kit and drive slowly to the tire shop for a $20 patch. I prefer the latter. Plus, if you're maintaining your tires weekly, you should notice any nails, screws or other cuts in the tires.

Everyone is different, and this issue has been beat to death on this and other forums, I just had to add my 2 cents. :thumbup:

If the difference is "massive", can anyone advise me how the ride would feel with 20" all season vs RFT? I am avoiding the 20's in favor of 19's because of ride firmness and all weather capability. If there is little difference with a non RFT, that would be very helpful to know.

It would especially be helpful now while the extra $2500 factory incentive is offered. With my specs, the dealer search turns up many more with 20" and only a couple with 19's. But none of these has all my options.

Thanks