As my RE040s are due for replacement soon, of course I'm looking at all kinds of options. Many here pan the OEM RE040 tires, but they aren't THAT bad IMO. You could certainly do a lot worse.... So what I found at Tirerack looks interesting and potentially performance enhancing:

According to Tirerack, the OEM 225/45-18s are 25.9" diameter/804 rev/mile with a 7.9" tread width

But get this - a RunFlat version in 245/40-18" 25.8" diameter 807 rev/mile with a HUGH 9.1" tread width is also available at a higher price.

What is amazing here is that you can get 1.2 inches ( ) wider tire in a size that almost exactly matches the diameter of OEM, keeping speedometer error low, while getting RunFlat safety.

So my question is does anyone know if runflat technology makes tires LESS roadworthy from a handling standpoint. Runflat technology seems to say the sidewalls are made stiffer than normal to support the car wo/air, and that would seem to be a good thing from a flat out performance perspective?

So does it follow that this actually could be a GREAT way to increase contact patch/have a stiffer-wider tire/improve handling at the track .... while getting some safety w/runflat to boot?

Anyone have experience or ever noticed these were available and got them? Thanks!

 

I've never driven a run-flat, but it seems they are constantly being panned in the automotive media as destroying the ride quality of cars due to the stiffer sidewalls. I'm thinking particularly about BMWs, but I know I've read it with other marques as well.

 

I've never seen anything said positive about runflats. The first mod on all the mini-forums is to chuck them...even if you've only got 20 miles on them. Utterly worthless tires in regards to handling, ride quality, ride noise, and even mediocre longevity.

 

Aren't the stock RE 040s run-flats?

 

No, they aren't - the owner of my local dealership swore up and down they were, I challenged him to prove it...he couldn't...they aren't.

(double check) if they were run flats they wouldn't give us repair goo/air compressor for 'free'.

<triple check> if they were we would have a much wider tread (9.1") than we do...we don't.

Besides, they don't even make a run flat in our size in the RE040.

 

By bad, I still haven't researched it again to be sure, but I distinctly remember the brochures, dealer and website stating that they were. Oh well, I guess I made my 1st mistake of the year. I'm slipping, I'd better be carful. :p