Quote:
Originally Posted by HighlandPete
Not sure what you are not agreeing with.  Changing from run-flats did improve the secondary ride quality, simply that there were other compromises to the move. One being the car lost some of the primary control, sorted with a higher performance damper. |
OK, I need to change my wording on that.
Since I joined the forums here I read many of your posts and felt all were "right on" and more important backed up by facts. So it's not really disagreeing with what you said, as all of it is in fact correct. I'm just thinking statement like “these cars are tuned for RF tires”, while true, will scare OP off from giving regular tires a fair chance (I think every owner should at least try what it's like to drive modern BMW without RF).
You are correct though, sidewall on RF is stiffer, and cars are tuned for RF tires. But for me that does not make them better handling tire in any area no matter the suspension. There’s no universal agreement among BMW owners which is better to use (the whole “no spare” silliness scares many to move away from RF), but I think most agree regular tires handle better.
It’s not like properly matched regular tire on F10 is anywhere close to folding or will introduce body roll when pushed. In fact it’ll make your rear end more planted by not harshly "skipping" over the bumps in higher speed turns. In my experience, these are more comfortable, have more grip, quitter, connect you with the road way more than RF, cheaper to replace, don’t wear as fast and don’t bubble as easily on impact. Add “safety” tire inflation kit to your car and you’re still not at the cost of replacing RF tires. And both RF and this kit may, or may not get you to your destination or closest service center.
Quote:
Originally Posted by HighlandPete
But how much difference and what value against the negatives, including the run-on-flat capability, without carrying a spare wheel, is all in the calculation to carry on with run-flats, after the issues in the E91.
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Safety of RF in my personal opinion is heavily overplayed argument. You know what else gets you to your destination (not to the first shop), good old fashioned full size spare tire in the trunk.
Some, maybe all (not sure??) M cars don’t come with RF tires, just safety kit and I don’t think that’s coincidence. Different suspension, sure, but these in theory go faster than “regular” BMWs on daily basis, if safety is concern, shouldn’t they have them too? People have been going high speeds on autobahn and race tracks way before run flat tires were ever considered.
I had unfortunate opportunity to ride on busted run flat with my family in the car, and it worked out great. But I also got to experience this specifically due to RF (pothole hit caused a bubble which burst soon after). Had the sidewall damage been any bigger I’d be stuck on the lake, in the woods, same way I now may get stuck if my Continental "ContiKomfort" kit fails me... no guaranties in life, with or without RF.