"New" Run Flats

[Jack Roadster]

I had replace my RFT tires on my 335 with Conti DWS a few years ago . Ride was much better, and handling was fine. I was planning on doing the same with my new 2014 Z4. However, I just read the reviews at Tire Rack on the newer RFT tires. They claim the ride quality is much improved. The RFT tires on the Z4 are not these newer ones.

Does anyone have any experience with the "new" RFT tires, and is the ride quality that much better?

[Lurcher]

Just took my "new" RF off last night and replaced with the Michelin PSS - wow - what a difference.

Never drove on the old ones - but if they were any worse - that would have sucked. Drove a 1 series this weekend with the same tires - just as bad....

[DslDwg]

I know the comparison is apples to oranges, but the Michelin RFT's I had on my 335i X-Drive were horrible. All the negatives were there, price, ride, noise etc.

My Z4 has the Bridgestones and I got to say they seem much better. Although still way overpriced.

Needless to say they will be coming off soon for a set of PSS's.

[Asbjorn]

Originally Posted by Jack Roadster

Does anyone have any experience with the "new" RFT tires, and is the ride quality that much better?

Not that I have heard of, but I think it is a great idea if you are running 17 or 18" wheels. Especially since this car was set up for RFTs from factory. I wish they had switched to these newer gen RFTs with the LCI.

Also try and do a search on the E9x forums! Someone there might have given it a try.

[rking117]

Yes I jsut bought OEM replacements for my Z and the ride is much better than the original. Tram lining is still a factor because the side walls are so stiff. There was a negative impact in handling since the new tire seems softer (or a more cushioned) ride. I can easily get squirrley going aroudn corners now which seemed to not be a factor of the original tires. My back is happy but my heart isnt.

[Asbjorn]

Originally Posted by rking117

Yes I jsut bought OEM replacements for my Z and the ride is much better than the original. Tram lining is still a factor because the side walls are so stiff. There was a negative impact in handling since the new tire seems softer (or a more cushioned) ride. I can easily get squirrley going aroudn corners now which seemed to not be a factor of the original tires. My back is happy but my heart isnt.

What are the specifications of the OEM replacements you mention? Such as brand, size and type?
I guess the originals you mention were Bridgestone Potenzas RE050A RFT?

[Jack Roadster]

These were the "new" run flats tire rack tested. The Bridgestone was rated highest. I currently have the REO 50 A I RFTs and am trying to decide Conti DWS (non RFT) or this new Bridgestone RE960 AS RFT.


Bridgestone Potenza RE960AS Pole Position RFT (Run-Flat Ultra High Performance All-Season 245/40R18 93W)

What We Liked: Best-in-class ride comfort and predictable handling
What We'd Improve: Add a bit more traction
Conclusion: This tire shows you don't have to compromise ride comfort to get extended mobility
Latest Test Rank: 2nd (pending winter test results)
Previous Test Rank: 2nd (September '11 versus a conventional tire)
Michelin Pilot Sport A/S Plus ZP (Run-Flat Ultra High Performance All-Season 245/40R18 (93Y) )

What We Liked: Direct steering feel and wet traction
What We'd Improve: Soften the edge of larger impacts a little bit
Conclusion: A performance run-flat tire that can retain its handling without a big sacrifice in ride quality
Latest Test Rank: 1st (pending winter test results)
Previous Test Rank: Not previously tested
Pirelli P Zero Nero All Season Run Flat (Run-Flat Ultra High Performance All-Season 245/40R18 93V)

What We Liked: Responsive steering
What We'd Improve: Wet traction
Conclusion: A reasonable run-flat option for drivers who don't emphasize wet traction
Latest Test Rank: 3rd (pending winter test results)
Previous Test Rank: Not previously tested
Yokohama AVID ENVigor ZPS (Run-Flat High Performance All-Season 245/40R18 93V)

What We Liked: Balanced dry weather handling
What We'd Improve: Ride quality and wet traction
Conclusion: A new run-flat design that isn't as refined as the best
Latest Test Rank: 4th (pending winter test results)
Previous Test Rank: Not previously tested

[jparnes1]

Jack, we're all looking forward to you being the 3rd generation RFT guinea pig!

[Pacemaker1000]

Nearly all cars that come with high performance run-flat tires use a summer only rubber compound to maximize grip levels and make the most of the car's power and suspension. While strong on performance, nearly all summer compounds are short on durability. Many of the customers I deal with are willing to give up a little high-speed performance for more mileage, so they opt for an all-season compound. We recently tested four of the leading high performance tires that maintain run-flat capability to see which one is considered the best.

The four tire manufacturers we tested (Bridgestone, Michelin, Pirelli and Yokohama) are globally recognized for offering high quality performance tires, so we put each model through a series of tests, both on our Real World Road Rides and on-site test track.

At the track, the Michelin Pilot Sport A/S Plus ZP led the way in wet traction and came in a close second to the Bridgestone Potenza RE960AS Pole Position RFT in our dry pavement runs where we simulate abrupt emergency avoidance maneuvers and other situations. The Pirelli P Zero Nero All Season Run Flat came in third with the Yokohama AVID ENVigor ZPS close behind as it didn't provide the same level of grip as the others.

Our Real World Road Ride consists of a 6.6-mile loop of two-lane roads, four-lane roads and expressways, as well as surfaces that include asphalt (some very smooth areas while others are patched) and concrete (complete with expansion joints and some studded tire wear) that are similar to what our customers can expect on their daily commute. Out on the road, we found the Potenza's new 3G technology can minimize the expected harsh ride that run-flat tires are known for and set the bar very high for all the others. The Pilot Sport A/S Plus ZP was just a step behind but both the Pirelli and Yokohama options seemed to transmit the noise and road feel from bigger impacts and expansion joints.

[HerrK]

Originally Posted by Pacemaker1000

so we put each model through a series of tests, both on our Real World Road Rides and on-site test track.

Have you done any testing on the new BS S001 RFT that is OEM on the new BMW F30's.

[Pacemaker1000]

^^^^
Sorry not me. This was cut and pasted from a review online.
Will try and find it for you

Anther review of new rft technology.
http://www.corvetteforum.com/article...sition-rft.php

Quote:

Bridgestone’s new Potenza RE960AS Pole Position RFT featuring their 3G technology raises the stakes in the run flat game with a ride quality hard to differentiate from the average non-run flat tire.

So why can't I find them for sale.

[mbetoni]

Originally Posted by Pacemaker1000

So why can't I find them for sale.

Article/page doesn't say when it was written, so could be simply that they're not in the market just yet.

Also, very important to note, it mentions that the comparison was done against the "standard RE960 AS", and that AS stands for All Season. ASs are different than a max performance summer tire like Michelin's PSS, so it's not exactly an apples-to-apples comparison for many. FWIW.