CNET On Cars - Smarter Driver, Understanding run-flat tires

You may have heard about run-flat tires but unless you drive certain cars, odds are you probably don't have them. CNET's Brian Cooley explains why this forward thinking tire technology just couldn't become the standard for all tires.

[valerieyearsago]

I actually like this reporter. He’s got the right type of energy when presenting things.

[atos.nympha]

I use run flat on my Mercedes diesel lost significantly on mpg but for some reason I feel more safe and comfortable since I travel randomly in the middle of the night usually out of state.

[bepiiforce]

I love my run flat tires. It was late at night when I got a flat. My hubby switched the tire from the front to the back and we drove a little under 100miles straight home. This is a game changer.

[demontwashington]

The 255/50R19s on my BMW are 10.5 lbs heavier than an identical non-run-flat. For _each tire._ Given that it's rotational mass and unsprung weight, that's guaranteed to have a huge impact on ride quality and acceleration. Can't wait to try non-run-flats.

[sigeamer]

Not only those cons, the ride is noticeably harsher. They also can skip under acceleration when taking a corner very fast (annoying, and more importantly very dangerous) I noticed a less amount of grip in the rain and in general. When outweighing pros and cons, run flats are not worth it at all

[BMTroubleU]

run flats "basically" immune from blow outs. i saw my fair share of them when customers ignored the runflat warning light on the dash

[zanastumasonis]

they are heavier but from my experience act like bigger sway bars. less roll, more stable and so on because the sidewall flexes so much less

[autoxerwgn]

BMW and other cars use them because they can save money by not including the spare and tools in the car. They can also use the space to increase trunk room or for other modules or maybe something like a urea tank in a diesel car.

[ra]

Sometimes when you're trying to escape an evil villains compound, having run flats is a life saver.

[lwriker]

I bought a used van with runflats. Little did I know the slow leaking one (fron dealer) would cost $750.00 per wheel. You HAVE to change two, not just one. So, $1, 500 to change both fronts. It'll take me a year to cough that up after spending savings on getting a used car in the first place. ITMT: I use a shop aircompressor every 2 days to get me to work everyday.

[_Negra_Arroyo_Lane]

Doesn't a stiff sidewall also mean a stiff and uncomfortable ride?

[matte]

Never liked these tires personally. They ride rough and they wear out faster. I work as a technician at a Toyota dealer and people who have an AWD Sienna van often opt for regular tires once the run flats are worn out. The ride difference is night and day between vans equipped with regular and run flat tires. The only thing I like about these tires is we get paid more for mounting/balancing them compared to regular tires.
I drive a BMW 335i and the first thing I did after buying it was getting rid of the run flats. I just bought a spare tire off some older 5 series. Ive had the car for 2.5 years and I’ve never had a flat

[BMTroubleU]

diesel bmw's dont use urea injection, they have a diesel particulate filter which has a regeneration cycle every so often to disintegrate the captured soot

[mimilower]

You will get 15 K miles on them if you're lucky. Replaced two sets on MB 2016 GLC (Pirelli Scorpian Verde); not driven harshly; after 30 K and four years, I gave up and purchased Bridgestone NON run flats (supposed to last 70 K). MB only offers run flats on 2020 GLC, but now allows you to buy a compact spare foe $200. No jack available unless ordered from Germany.

[murwaz]

Had a guy here in sweden this week, he got killed trying to change tire on his car, a house on wheels ran him over poor guy... :( R.I.P! ...so I'd say runflats are good for more then one reason! ^^

[bield]

Personal choice of course, but I’m sticking with RFs. Yes, the ride’s a little harsher and road noise higher, but the handling’s good and grip levels are fine. But it’s safety that especially makes me stick with them. Had a blowout last year on a motorway without a hard shoulder. The RFs got me home NRF would have been a whole different story…

[thabg]

You forgot 1 more con, run flat tires have a short tread life

[abufaisal]

Worst product ever. Causes vibration, stiffness, road sound, expensive, get damaged quickly and non reparable. I got rid of them and replaced them with regular tires, now it rides smooth like I'm driving on glass. Now I'm driving a BMW instead of a bone shaker.

The question is BMW, Why ????

[chard]

So Run flats are basically just thicker and tougher tires right?

[pennywisetheclown]

Jeep grand cherokees have run flats. The higher end performance models. Those are big tires 295 35r 20 if memory serves me correct. The poor tire machine struggled to get them off the rim from the stiff sidewalls