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

[@atos.nympha3451]

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.

[@bepiiforce5760]

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.

[@valerie80yearsago90]

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

[@Andrew-zv4fm]

He is better then all of them.

[@bigshash9946]

Yeah...he was easy to listen to.

[@demontwashington5388]

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.

[@brewking2]

I'm curious if you plan to carry around a spare tire when you change to normal tires? Honest question.

[@demontwashington5388]

I run non-run-flats in the winter and got a spare, just to be sure. Winter tires ride WAY better than the summers. Seriously thinking of not waiting for the OEM run-flats to wear out and just chucking them - or stashing them to put back on if I decide to trade it in.

[@hectorjoemulligan5729]

My question is, with conventional tires where does the spare tire go now?

[@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

[@allenho2778]

German cars are supposed run harsh. I love the road feel.

[@AdrianJayeOnline]

@@allenho2778 errmm no there not, I've had several, Porsche, Mercedes and BMW

[@allenho2778]

@@AdrianJayeOnline I disagreed with sigimmer about skipping around a corner. It is true the ride is harsher compared to American and Japanese Autos.

[@rileysmith9843]

Don’t forget that most cannot be repaired.

[@allenho2778]

@@rileysmith9843 I do European Delivery every five years, so it is not an issue for me. In case you have not noticed, most of the OEM are simply replaced rather than repaired.

[@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.

[@HCkev]

In fact, many manufacturers don't include a spare tire anymore so they can save weight and quote higher MPG numbers...

[@lwriker1304]

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.

[@bield7]

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…

[@ra55575]

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

[@308_Negra_Arroyo_Lane]

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

[@zanastumasonis]

depends what you're looking for, it will make the car more stable, it will move side to side less, will feel and be more planted when turning hard and so on

[@jayjay378378]

Yes

[@matte8441]

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

[@marleycolin954]

I dont mean to be so offtopic but does anybody know a way to get back into an instagram account?? I stupidly forgot the password. I love any help you can give me!

[@joemiles8402]

@Marley Colin instablaster ;)

[@marleycolin954]

@Joe Miles i really appreciate your reply. I found the site thru google and Im in the hacking process atm. I see it takes a while so I will get back to you later with my results.

[@marleycolin954]

@Joe Miles It worked and I actually got access to my account again. I am so happy:D Thank you so much, you really help me out!

[@joemiles8402]

@Marley Colin You are welcome =)

[@gary_beniford]

still waiting on airless tires

[@jkxss]

Have you seen those humvees with the adjustable treads like on tanks?

[@m3lowiesvlog715]

jump oricakle No way,because the tire,insurance and tow companies gotta make money out of your pocket.

[@numbereightyseven]

Go back a hundred and fifty years.

[@playboysosexy1]

Got continental on my bmw 5 series bout to hit 60k miles on it now and still going in hard but they retail at 230 per tire

[@mimilower5016]

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! ^^

[@arlind530d]

A house on wheels?

[@potatoyes246]

@@arlind530d maybe an RV? lol who knows, cmon guy with the 8 y/o comment TELL US

[@chard8114]

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

[@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

[@abufaisal7668]

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 ????

[@AdrianJayeOnline]

actually it's to save cost

[@karanb8489]

@@AdrianJayeOnline how does it save cost when in actual they are more expensive than regular tyres?

[@technikleo3797]

@@karanb8489 It saves weight and space compared to spare tires.

[@somestuffithoughtyoumightl6985]

@@technikleo3797 I’m going to lean more towards cost, considering the difference between sprung and unsprung weight savings.

[@joelrangel6620]

Is 5lbd really a big difference, it’s like going to buy groceries now you have the difference in weight of all 4 tires in the trunk

[@Pertamax7-HD]

nice explanation

[@pennywisetheclown9090]

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

[@malrofo]

is slime inside tires still a thing?

[@dutch_blades]

Thinking of changing out the run flats on my e92 325i for regular ones, but I'm not sure yet... Ride quality is amazing, but might improve even more with regular tires...

[@Ghost-vr5zg]

I have an e39 540i with a full size spare, guess that's when they stopped with the spare and started with runflats.

[@NicholasL2288]

My family’s Honda Odyssey has it...

[@thabg007]

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

[@joapps8135]

thabg007 that depends

[@maxfury7226]

Totally not true

[@johnqiu1659]

@@maxfury7226 technically, the higher the weight the less tread life. The runflat weighs more, this less tread life lol

[@maxfury7226]

John Qiu? I’ve leased 3 BMW’s and never had any issues with the tires being worn...maybe you were just using cheap tires! Lol!

[@thabg007]

@@maxfury7226 no I never purchased run flat tires, but now I have a a newer car that came with run flats, they are holding up fine, guess I was wrong about the tread life

[@19501960]

Run flat tyres are only of benefit to car companies. I have had run flats on BMW's for a while you will be lucky to get 15 miles out of them flat especially lower priced ones they get shredded. and if you have a flat tyre at midnight ? good luck with that. I suggest use run flats between 8am and 6pm when garages are open.

[@malchazmichael949]

What tire cut ... can I ride on a Mercedes w220? Forward 245/35 / R19 .. is that ok? Back 275/40 R19 is that ok? It will not touch the rear wing 275/40 / R19?

[@jackd232]

Can't find any new cars don't have them right now. So the new tech is better after all. Safety bigger than a little bit comfy.

[@waltermolina7115]

What about potholes? Do run flat tires are better than a conventional tire when they hit a pothole?

[@richu5192]

MINI offers tire and wheel insurance due to the propensity of both the runflat tires and wheels to be destroyed by potholes.

[@goldensunshine1910]

Very easy to understand. Thank you.

[@Trihawk7]

True, my dads 2012 Jag XF runs around £460 to change all 4

[@TheMonkeyFarted]

With that they give you no jack and tools to chance the tire? I bet tow trucks love people now a days because most people don't know how to do even basic maintenance on their cars.

[@holahovito11]

Can't believe this team got to the superbowl over the Saints.

[@disnalee]

I have the PAC MICH TIRES ON MY VAN, CAN I JUST REPLACE IT WITH OTHER RUNFLAT TIRES and where can i get it done???

[@isaac13d]

Took a year for me to see your comment, but you can just ask for run flats at pretty much any place that sells tires, I used to sell tires at a Sam's Club and we also sold run flat tires. There aren't special rules for replacing run flat tires, but you can't repair them due to the fact that the sidewalls do wear when you actually "use" the run flat part (we used to offer free repair for anyone with a membership so it wasn't always worth it unless the vehicle didn't come with a spare).

[@7150285]

does run-flat tire's aspect ratio have to be extremely low or can it be like very high like 60% aspect ratio?

[@youorme868]

Spent the whole day trying to find a place where they can patch my run flat there puncture. That’s another difficulty, not everyone ca service them

[@nicoleilechie3789]

Were you able to find one? Just got a nail in my run flat and Mini told me to repalce the entire tire rather then patch it. Like i havent even had these new tires for two years yet. SMH

[@AdrianJayeOnline]

BMW and other high end cars are going back to putting ordinary spares back in due to the issues and backlash

[@saldi3543]

they only have one problem, noooiiiisssseeee

[@doityourway3857]

Is better to have a spare tire down to have for heavier tires

[@Snoopy484]

You should really have your on channel. It's not fair to put you on the same channel as the rest of CNET

[@BMTroubleU]

oh ok my bad- they dont in australia

[@Andrew-zv4fm]

I wonder how well this video aged.

[@spreadeagled5654]

My new Mercedes-Benz C300 has the Continental “run flat” tires. They are called “MO” tires. (Mercedes Original) They are available at the Mercedes-Benz dealership service department only. If I get a flat tire, I have to go to the nearest tire shop, who do not stock them. Since the MO tire cannot be repaired as regular tires, they must order a new MO tire from a nearest Mercedes dealer, have them deliver it, and they would mount and balance it, and then install it. In the meantime I have to wait until the job is completed. How long do I need to wait? It all depends on the distance from the tire shop to the nearest Mercedes-Benz dealer and if I’m out in the boondocks, it’s gonna be a while. 😫

[@madblast658]

immune to blow out? my 7 has had nothing but blowouts with runflats. No give in sidewalls always causes them to blow out when any form of pothole meets them.

[@buckshot6481]

Goodyear double eagle, tire in a tire, when there's no man around !

[@skip70]

3:13 what the heck does he say there? I can't understand it. it's almost like they scrubbed it.

[@mftran]

If anybody has trouble understanding the weight difference, the difference is in "unsprung weight".

[@7150285]

yes, all the bullet proof vehicles uses these tires...

[@chrisnamaste3572]

DO NOT BUY RUN FLATS--Especially if you have TPMS. If you must then buy the Bridgestone RE960 or Driveguard --they have decent ride quality and longevity.

[@chicagobac]

Chris Namaste I got Driveguard recently. Has a horrible road noise. Mechanic said everything was ok, just a tire noise. Are they supposed to be like that?

[@TheCharleseye]

Nah, I'm good. The spare and tools help with my weight distribution.

[@mobeen1982]

Run flats are shit, ruin the ride on a car, carry a spare or have recovery service

[@7150285]

yup

[@BossChronicles]

No wonder my cla didn't come with a spare

[@Andrew-zv4fm]

This video was posted 7 years ago and they said that a tire shop may not have a runfalt tire for you. So, 7 years later in 2021 has this changed?

[@Andrew-zv4fm]

@@raychristy5027 except Porsche.

[@arlenerico8362]

Character In the video It's great, I like it a lot $$

[@bilalahmed2123]

Mercedes-Benz uses them too !

[@AdrianJayeOnline]

Don't be fooled, the main reason is cost savings, no tire/wheel/no jack, think about it, if you could save a dime on not putting say a washer on a car, how many dimes do you save on selling a 1000,000 cars ? Now work out saving say $100 (at cost) for 1000,000 cars, that's a lot of money. got nothing to do with safety, environment or anything else, its about DOLLARS & CENTS

[@scarto28]

at min 1:03 is the Michelin PAX System not RFT (run-flat ) .

[@SWAGURA]

Run crap tires

[@zhuolizhang7837]

5lbs more for each tire, total 20 lbs more.... that is same weigh of a donut tire. so using these more expensive can save space only

[@ambitionsskyyyy]

5 pounds is a lot of weight when it’s rotational mass.

[@W1ldmutt]

At least you can run from the cops for a little longer...

[@psneves]

A tubelesss tire will take 3 weeks to go flat with a puncture.

[@trilliedon8728]

I’m good. I’ll stick to traditional tires with a spare. Run flats are unnecessarily overpriced

[@VintageCars999]

Runflats, because the idea of having a real spare tire you wouldn't get to spend loads amount of money in a short time when your tire needs replacing. No thanks, i'd prefer to keep my regular spare tire (not a cheapo donut tire either) instead. The only good thing about runflats is you can get off the highway to replace that tire with your spare.

[@mattmiller4778]

5lbs isn't that dramatic of a difference

[@rockbrod]

Matt Miller x by 4 tyres makes 20ib

[@stevenhs8821]

Also this is unsprung weight which affects suspension dynamics. So 5lbs is quite significant. More than those cool alloy wheels are saving.

[@amirooo5189]

Matt Miller But you are saving one spare tyre + metallic accessories and their space... I’ll say weight is not an issue

[@johntechwriter]

Five pounds is a major difference, not only because it is unsparing, but also because it is “rolling weight.” Every time the driver accelerates the inertia of those 20 lb. of extra mass on each corner must be overcome. That means lower fuel economy and reduced performance. The inertia problem manifests itself again under braking: longer distances, increased pad wear. With today's tires and roads, flat tires are a rarity. Better to use regular tires and carry a space saver spare, and call AAA on your cell phone if you have a flat. Chances are you will never have to. Run-flats are a gouge by BMW, which has declined from a driver-oriented manufacturer into just another greedy car maker. They charge a fortune for replacement run-flats and don’t have to provide a spare, which saves them money.

[@arifabdullah7142]

Run flat tyres : UNCOMFORTABLE, NOISY AND BUMPY

[@stebarg]

0:53 aha, so you are changing a wheel in the USA. Interesting. 😁

[@at9670]

My glorious BMW e46 from 2004 had both a full size spare tire and a battery... I like to think of modern car manufacters as crooks

[@3dRoma3d]

then tire sales would decrease and tire manufacturers are a business.

[@arlind530d]

I don’t wanna understand runflat tires i wanna avoid them

[@JoseRodriguez-pq5sz]

These tires are horrible. You better get tire insurance. Their life expectation is like 1 day

[@TomO-if7nh]

5 pounds is not "dramatically lighter"

[@james4v261]

Tom O its rotational mass yes it is.

[@TheIrfanxz44]

DON'T buy run flats They will wear out with 25k miles and crack your Rims

[@ManBearPigJake]

My Camaro uses it ;)

[@larrymyers209]

Cooley is obviously biased concerning run-flat tires.

[@woodyahh2110]

Run flats are not lighter

[@wanrosli5690]

RFT only for the olders and the rich..

[@MrApplesaucestuff]

biggest scam in motoring

[@AdrianJayeOnline]

RFT's are crap. they are TWICE as expensive, they are often UN-REPAIRABLE, they WILL only do a maximum of 50km, and they are TOAST afterwards. ride is crap, harsher, tramlines and wear out faster than your mother can drop her knickers. WASTE OF MONEY

[@cmichael442]

Any one who prefers the traditional system with spare tires, either can't afford run flats or has never nearly lost control on a blow out / changed a tire in their life at 3am with rusty lug nuts only to find the spare is also flat.

[@pyrofful]

It's a father's JOB to teach his kids (or wife if she doesn't know) how to change a tire. It's great if the guy will do the work on the side of the road but a woman and kids as the grow should be tough this. Its not typically THAT HARD to do.

[@jackjalowitz1487]

lol, corvette u wish

[@klepetar]

run flats suck.. do not buy them...suuuckkkkkkkksss!!!