jdag

I just was bit by the run flat bug. I've read about it, but just didn't want to believe it. Until today when a bulge developed, the ride got extremely rough, and then the tire popped, sounding like a gunshot. The only positive is that the current tires are pretty close to end-of-life anyhow.

Being a Saturday afternoon, I am pretty much out-of-luck until Monday. I am considering my options and made a number of calls, but received different recommendations on each call, so figured I would turn to this board for input. The car is a 2016 C300 sport with 225/45-18 & 245/40-18 tires. My thoughts are:

1) Replace with same OEM tires: Continental ProContact GX SSR Grand Touring All-Season. I am not thrilled with the life of these at all. But it is the "simple" choice.

2) Move to non-run flats: Michelin Pilot Sport A/S 3+ (W- OR Y-speed rated) Ultra High Performance All-Season. And, are these the recommended Pilot Sports as I believe there might be a number if different options. What is the life-expectancy on these?

3) Get snow tires now, then choose new tires in the spring. If I were to go this route, would you suggest the stock sizes or getting 4 equal sized tires? And Bridge Blizzak WS80, Mich Xice Xi3, or Conti Winter Contact SI? I've been driving for 35 years and have actually never once driven a car with snow tires, and I live in Rochester, NY, where we have very rough winters.

4) Lastly, the Conti run flats are Grand Touring All-Season and the Michelin Pilot Sports are Ultra High Performance All-Season. What is the difference?

Any suggestions? Thanks in advance, John

MASSC450

Tough decision, I know. I guess it depends on a couple factors:

1. How much did you hate the stock run flats.

2. Do you own or lease.

3. If you buy non-run flats, what will you do for a spare...or do for tire repair if you pick up a nail.

I own my vehicle, so I went the route of buying a second set of Mercedes AMG wheels/tires on ebay for my C450. Both of my sets have the stock run flat tires...19" multispoke with performance tires in Summer, and 18" five spoke with A/S tires for Winter, which by the way worked pretty good in snow on my old 2015 C300 Sport 4Matic. I went this choice because I didn't want to deal with lugging around a spare/jack all the time or deal with Fix a Flat...but in an emergency or for long trip I could use one of my other wheels as a temporary spare if need be.

As for the biggest difference between regular all-season tires and high performance all-season tires...your car will handle better on dry roads with the latter.

Mike5215

Rochester born and raised myself. Currently in Florida. I highly recommend it

I'd get the snows for the upcoming winter and a set of Michelin Pilot Super Sports for the three weeks of summer you guys get up there. Treadlife is 35k Miles on a square set up, half that for staggered.

jdag

Thanks to both of you. Mike5215, I've lived here all my life too. I am hoping this winter is like last, which was mild with very little snow. The 2-3 before last year were horrendous though.

Mike, you bring up "treadlife is 35k Miles on a square set up, half that for staggered." Is there any issue with just getting the 4 Pilot Super Sports of 225/45-18 size and calling it a day? Is there any effect on the functionality of the car, odometer, speedometer, ABS, etc.?

I do lease, and the 15,000 miles on the run-flats is a joke (let alone the tire popping). With an expectation of driving 45,000 over the term of the lease, I would have to replace tires again next year at this time. And then, potentially even just before turning the car in. That's actually the 1 reason I am considering snow tires. It would alleviate that problem since ~10,000 of the miles would be consumed by the snow tires.

Mike5215

Yeah, you wouldn't want to rotate the wider rear rims up front and vice versa. Rotating is what allows for the longer tread life. I'd stick the RFs you have now in the garage for lease turn in, get a set of snows and the MPSS, and run the MPSS for three summers.

jdag

The problem is my current run flats are likely all near or even below the acceptable least turn-in limit. So I need to replace all 4 anyhow. The blown tire just expedites this by a couple of months.

The Pilot Sports sound like an option, but not without downsides. Their life expectancy isn't stellar considering that I cannot rotate them. And I'd have the downside of no spare (unless I piece together a solution of either a spare floating in the trunk and/or a repair kit).

Makes me think I just might as well live with the run flats and accept it.

I have to say, I am not impressed.

Thanks, John

Mike5215

I'm on the staggered 18's as well. Got the MPSS and a Slime Seal & Fill kit because I wasn't thrilled with the ride quality or noise from the RFs. They're a huge upgrade.

jdag

Thanks for the help, Mike. I will go with the Michelins if they have them in stock. I need to get this done on Monday, so my guess is that I will need to go with the Conti run-flat tires, which I would hope/expect that they have.

I am in a hurry as I am down to 1 car. In the ultimate case of Murphy's Law, we are down to only the C300 this week. I returned my g37x on Thu 10/27, and we will be picking up our GLC300 this week. We custom ordered the GLC ~8 weeks ago, and knew it would be in roughly the time the Infiniti lease expired, give or take a week. The dealer told me on Wed that the GLC has arrived in the US, and we should be able to pick up 11/4-11/5. So I returned the Infiniti, which expired 10/28, thinking we'd be OK for a handful of days with 1 car (my wife travels virtually every week anyhow, including this coming week). Then the tire blows! UUGH!

Mike5215

Got it. They're usually not in stock and the fronts in our size were only available thru TireRack. I used their ship to installer option and they were on the car in 3 days. You should be getting ready to go to snows anyway though right? My mom and brother are still up in Roch and they got a tiny bit of snow last week.

jdag

Thanks again.

jdag

I did end up getting the Michelin Pilot Sport A/S 3+ tires installed today. The MB dealership did well for me, getting them very quickly.

I only drove home from the dealership, so ~15 miles. But I will say I am HIGHLY IMPRESSED. The car was quieter and significantly smoother than with the stock Continental RF/MOE tires.

I am a bit uncomfortable not having a spare. But the fact is, I was very uncomfortable with the blown RF anyhow, and my car was down while waiting for the new tires.

Is anyone aware of a compact spare wheel/tire that will fit the 2016 C300 Sport? I would not mind having it in the trunk as I rarely need the space anyhow.

Mike5215

Amazon sells a Slime Seal & Fill kit for around $40. Seemed more practical than a wheel, plus a jack. I've probably put 200,000 miles on Michelins over the past ten years and 4 Mercedes and I've never had a flat, but of course you never know.

jdag

Yeah, I am probably over thinking this. I've always had a spare...and this w/e was my 1st blown tire in 33 years of driving.

Mike5215

Ironically, the run flats blow out with much higher frequency. Mine weren't on the car long enough to blow out, but I still swapped them out for ride and noise. Actually I did research on TireRack and the highest rated tire was the BF Goodrich Comp TA so I got a set. Ride as nice as the MPSS but the design was so funky looking I had to pull them off.

jdag

Well, the unscientific conclusion I am reaching is that the run-flats are a great in concept, but not in execution. If there is in fact a higher failure rate, without a spare, you are actually more likely to be in compromising positions with them.

Of course, you simply never know. I have 4 brand new tires and I can destroy them all today if I drive over nails or back up over those 1-way spikes!

jdag

Mike - Extension on my questioning...At what pressure do you run your Michelin Pilot Sport A/S? Thanks, John

Mike5215

I'm actually on the summer (vs all season) version of that tire, the Michelin Pilot Super Sport. Off the top of my head they're at 38 but don't quote me. The car has been at a body shop for a month so I can't check them.

jdag

Thanks, Mike When I picked up yesterday they were at about 35, which seemed a bit low.

SV-

OP, I hate runflats too : 11000km and 5 months into the lease and already three tire bubbles. Spent around 500 CAD replacing 3 tires (thanks to Pirelli's road hazard warranty which covered a good part of the tire cost).
I got a few questions, because my wife drives that car and does lots of highways, so I'm worried :

1) You got a bulge in your tire, do you mean you actually felt it while driving or you saw it when parked? And how long did you drive on that bulge before it blew out?
2) Did you lose control/how fast were you going?
3) Did you hit a pothole right before it blew out?
4) Did you damage your rim?

I think you took a great decision with the non-RF.

jdag

Wow, that's less than 1/2 the mileage I experienced. Terrible! To address your Qs:

1) I believe that the bulge developed pretty quickly, and burst shortly thereafter (see below).
2) I did not lose control, but was only going ~35mph when it popped.
3) I did not hit any potholes or bumps when it blew. But it was LOUD when it happened. It sounded like a gunshot.
4) Thankfully, I did not damage the rim.

It is hard to say exactly when the bulge developed, so I don't know for sure how long it was present before bursting. I picked my wife up at the airport on Friday night, and then we drove together to my parents' house on Saturday morning. She then took the car alone for ~25 miles.

When we left my parents' house, I drove, and she said "the car sounded loud when I came back here" as we pulled out of their driveway. And boy, it didn't take more than 5 seconds for me to notice it as I got to about 20mph. It was significant.

The noise level and vibration was absolutely not present when I drove to my parents' house, so the it must have either developed or worsened while she was out alone. She did say that she thought the car sounded a bit loud on the way home from the airport on Friday night, but I did not notice it then, and I am always noticing every creak/buzz/rattle in my cars.

Anyhow, we drove ~2 miles, and I pulled over at a gas station. When I looked at the tire I noticed the bugle within seconds. It was huge, probably close to the size of a baseball, on the inside of the front tire. Thinking we were OK on the run-flats, I drove home, ~4 more miles. Then, when I was heading to the dealership, the tire blew ~2 miles after I left home.

So in total, from the time the noise/vibration was really noticeable, it was under ~30-35 miles until it blew.