RFT vs non-rft

turboawdfanatic · 02-11-2008, 11:23 PM

After reading all the posts about how the stock 18" rfts suck, i decided not to get the tire warranty. Especially since I always get a new set of rims/tires, and was told the insurance doesn't cover aftermarket tires/wheels. Today I just realized my 08 Dec build that i took delivery of almost 2 weeks ago, came with Michelin PS2's. I know the non-rft ps2's have gotten very good reviews, compared to the non-rft re050a. In the few hundred miles i have driven, i don't get the sense that the ps2 rft's are any harsher than any other tires I've used, no tramlining ,and have no complaints so far
I wonder if i should have just gotten the warranty?

Now into the more technical discussion. why such a dislike to rft's? and why do people think they are not as performance oriented as their non-rft counter parts. My understanding is that the compounds are the same but the sidewalls are reinforced and stiffer, so that they can support weight when low on air. Being in the auto-x circle, most people prefer a tire with a stiffer sidewall, so that they can have max contact patch, w/o having to over inflate, and still keep the sidewall from rolling over. Wouldn't the rft version allow you to run lower pressures, keeping a flatter/greater contact patch, and have less sidewall flex since it's stiffer?

ZBMW · 02-12-2008, 10:25 AM

The major problem with runflats are that they are expensive to replace. I've read a lot of opinions here about how they suck but everything I've read in the car mags has been that they are pretty good.
My track experience with them was very good. I couldn't break them loose and they held up under hard braking. Of course they have limitations because they are still a street tire. I didn't fool with tire pressures because I was so new to the car (1200 miles at the time) that I just wanted to get familiar with the stock setup. Tire Rack people will have that info.

BMW F22 · 02-12-2008, 11:04 AM

I would say the main reasons are the cost to replace them and the ride quality. Because RFTs have reinforced/ very stiff sidewalls, the ride is more noisy and harsh than non-rft.

turboawdfanatic · 02-12-2008, 11:20 AM

Cost to replace i can see. But in the couple hundred miles I've driven with the rft's. Although i haven't driven a 3 w/o rft's....the ps2 rft's just don't seem any harsher/louder to me than non-rft's I have on my other cars.

02-11-2008, 11:23 PM	#1
turboawdfanatic Lieutenant 50 Rep 554 Posts Drives: 3 Join Date: Nov 2007 Location: US iTrader: (5)	RFT vs non-rft After reading all the posts about how the stock 18" rfts suck, i decided not to get the tire warranty. Especially since I always get a new set of rims/tires, and was told the insurance doesn't cover aftermarket tires/wheels. Today I just realized my 08 Dec build that i took delivery of almost 2 weeks ago, came with Michelin PS2's. I know the non-rft ps2's have gotten very good reviews, compared to the non-rft re050a. In the few hundred miles i have driven, i don't get the sense that the ps2 rft's are any harsher than any other tires I've used, no tramlining ,and have no complaints so far I wonder if i should have just gotten the warranty? Now into the more technical discussion. why such a dislike to rft's? and why do people think they are not as performance oriented as their non-rft counter parts. My understanding is that the compounds are the same but the sidewalls are reinforced and stiffer, so that they can support weight when low on air. Being in the auto-x circle, most people prefer a tire with a stiffer sidewall, so that they can have max contact patch, w/o having to over inflate, and still keep the sidewall from rolling over. Wouldn't the rft version allow you to run lower pressures, keeping a flatter/greater contact patch, and have less sidewall flex since it's stiffer?
	Appreciate 0 Tweet Quote

02-12-2008, 10:25 AM	#2
ZBMW Black Forest Bimmerphile 2 Rep 137 Posts Drives: 2007 335i Join Date: Jan 2007 Location: Colorado iTrader: (1)	The major problem with runflats are that they are expensive to replace. I've read a lot of opinions here about how they suck but everything I've read in the car mags has been that they are pretty good. My track experience with them was very good. I couldn't break them loose and they held up under hard braking. Of course they have limitations because they are still a street tire. I didn't fool with tire pressures because I was so new to the car (1200 miles at the time) that I just wanted to get familiar with the stock setup. Tire Rack people will have that info.
	Appreciate 0 Quote

02-12-2008, 11:04 AM	#3
BMW F22 Major General 3566 Rep 9,788 Posts Drives: ///M235i Join Date: Nov 2005 Location: Bay Area iTrader: (8)	I would say the main reasons are the cost to replace them and the ride quality. Because RFTs have reinforced/ very stiff sidewalls, the ride is more noisy and harsh than non-rft.
	Appreciate 0 Quote

02-12-2008, 11:20 AM	#4
turboawdfanatic Lieutenant 50 Rep 554 Posts Drives: 3 Join Date: Nov 2007 Location: US iTrader: (5)	Cost to replace i can see. But in the couple hundred miles I've driven with the rft's. Although i haven't driven a 3 w/o rft's....the ps2 rft's just don't seem any harsher/louder to me than non-rft's I have on my other cars.
	Appreciate 0 Quote