Getting two flat tires in a single trip takes some luck, and getting two flat tires within 25 minutes takes some skill. But when the tire we're discussing is the same tire...well, I'm not sure what that takes. Maybe it's just a matter of acknowledging a greater power really wanted that tire to be flat!
Or at least as flat as our long-term BMW 750i's run-flat tires can be.
It all started with a random lane change on the 101 freeway. Halfway through it I spotted road debris but I had no real option to avoid it without massive steering input at roughly 65 mph. It looked like nothing more than a blue party streamer, so I didn't think it deserved drastic or dangerous action on my part.
Bam!
"Hmm, that seemed loud for a paper streamer..."
About 10 minutes later I heard a "DING" and the LCD screen lit up with the first message above. I figured it was more than just a paper streamer I had hit with my right front tire. But at that point I was on Malibu Canyon Road with no where to stop, plus I knew the BMW 750i had run-flats so I figured I'd get to PCH and stop at a gas station.
Once parked it didn't take long to spot the problem. In fact, a good chunk of the blue streamer remained with the tire, conveniently marking the nail's location. And once again, between the run-flat sidewall and the lack of any obvious signs of air loss (no squished sidewall or scary sounds, vibrations or pulls from behind the wheel) it seemed a no-brainer to continue on and stop at Stokes Tire Pros in Santa Monica for a simple patch. I even called ahead and told them I would be there in 15 minutes.
Probably about 45 seconds after hanging up, while heading south on PCH behind a large truck (I was staying in the slow lane and keeping it under 45, just to be safe) I spotted a massive pothole just as it slipped out from under the truck before disappearing under the BMW. It was on the right side. Lined up perfectly with...
BAM!!
The right front tire, already confirmed to be carrying a nail and rolling on low tire pressure according to the 750i's gauge cluster, slammed into said pothole.
This was immediately followed by a definite sound, vibration and pull coming from the right side of the car. I uttered several inappropriate words and pulled into another gas station to see if there was any visible change in the tire's condition. The now-drooping sidewall was easy to spot, but a closer examination revealed the new issue with the tire.
I've rarely seen a tear this large in a sidewall, and I've never seen one like this in a run-flat tire. I'll probably never know if the pothole would have done this to any tire, or if it was a combination of the existing low tire pressure and the impact that ripped this hole in the 245/45R19 Goodyear Excellence.
I still made it to Stokes (about 10 miles away), but I was now using the flashers and staying under 30 mph. They had to special order the tire, but they had it installed by mid-afternoon. They also gave the car a four-wheel alignment, something I suggested given the severe impact and clear evidence of force traveling through the car's right-side front suspension.
Final bill: $473.62.
I now have a new appreciation for the capabilities of both run-flat tires and potholes.
Karl Brauer, Edmunds.com Editor in Chief @ 19,730 miles
audikrazy1 says:
02:22 PM, 10/30/09
i thought scott has the 7 down in Vegas?
Karl Brauer replied to comment from audikrazy1
02:48 PM, 10/30/09
This was a few days ago.
actualsize says:
02:51 PM, 10/30/09
Run-flat sidewalls start breaking down and eating themselves from the inside the moment the air departs -- that's why few (if any) have more than a 100-mile life in airless mode. And it's the reason why a tire store won't patch a run-flat that's been, well, run flat.
So this tire's death clock had already started ticking-down before you hit the pothole. The impact merely over-stressed the precise sidewall/shoulder region of the tire where internal breakdown was already in full swing.
Would the pothole have created a pinch-flat if the tire had been fully aired? Hard to tell, because I didn't see the size and depth of said pothole. But it certainly would have stood a much better chance of shrugging it off.
wobbly_ears says:
03:20 PM, 10/30/09
California's infrastructure is, literally crumbling before our eyes! Potholled freeways, crumbling bridges, malfunctioning signals.....
Drive safely Californians!!!
greenpony says:
03:43 PM, 10/30/09
Tsk tsk. Tailgating a truck when you know you have to be careful.
vt8919 says:
07:28 PM, 10/30/09
I guess your luck ran flat that day...
hybris says:
07:53 PM, 10/30/09
I'm guessing that the 750 doesn't have a spare tire?
cwc1 says:
08:05 PM, 10/30/09
Wow, that is a serious tear, from a serious pot hole.
So if run-flats are living on borrowed time from the moment they go flat, then what's the point of having them if tire places won't patch them, since they're mortally damaged by the time you get there? When some manufacturers like BMW don't even give you a choice nor have a place to store a conventional spare if you switch from the run-flats, what else can the driver do but drive on the tire after it's lost air until they get to the tire place -- call road service? Then, what's the difference from using regular tires and not having a spare?
This essentially makes run-flats a very expensive disposable tire if one ever gets a puncture.
bimmerjay says:
01:26 AM, 10/31/09
"This essentially makes run-flats a very expensive disposable tire if one ever gets a puncture."
This is exactly what they are.
Although if I ever experience a complete blowout at 80 mph, I sure would rather have a runflat under me. A conventional tire would likely separate from the rim and could cause a loss of control, whereas the runflat's much stronger sidewall is much more likely to hold the tire on the rim.
bodyblue says:
05:00 AM, 10/31/09
$473 for one tire and alignment??????????? I thought I heard somebody scream "RAPE"
hybris says:
06:24 AM, 10/31/09
Personally if I had to have a run flat tire I would want the type that had a extra heavy duty plastic ring that goes around the wheel so you could use regular tires.
epbrown says:
07:53 AM, 10/31/09
The big advantages of run-flats are 1) you don't lose control of the car during a blow-out and have an accident, which is a pretty nice feature here, and a godsend in Germany where highway speeds mean a blow-out is fatal. 2) you don't have to stop driving immediately, no matter where you are, with a flat. No more getting stuck in the middle of nowhere, in a bad neighborhood, in the snow, rain, subzero cold, next to a busy freeway, with a carload of kids. The fact that we've eliminated any chance for another sequel to Wrong Turn makes it well worth the cost.
The real issue with these tires will be human nature. Remember the "donut" spares? These temporary spares are just to get you to the next station to replace or repair your flat - they're smaller, narrower, and not supposed to be driven above 40 or so. How many times have you seen some car doing 70 with one, or seen the same car running one for weeks or months? I see it all the time.
Well, twice I've met people that had been driving on flat run-flats DAYS after the tire lost pressure. "What - I haven't had time to go to the tire place, besides the car drives fine."
cr_driver says:
10:35 AM, 10/31/09
Given these info I aint liking run flats....
chavis10 says:
01:56 PM, 11/23/09
Sheesh- that was a nasty gash.
sixwheeler says:
11:42 PM, 05/13/10
This has been the story of my life with my 2008 Miata. Saudi Arabia is big-sidewall-SUV country.