: Run-flat tires?



billeee
09-14-12, 07:02 PM
I was playing around with the "Build Your Own" feature on the Cadillac web site. It looks like run-flat tires are the only option? I've heard nothing but bad reports on them (heavy, hard riding, and reduced traction). Anyone know of other options from the factory?

investor74
09-14-12, 07:13 PM
If you get the Base model, you get regular all-season tires and a free can of fix-a-flat. Luxury and above are run-flat. No factory options, but the dealer could possibly swap them for you if you really don't want them.

My neighbor has run-flats on his BMW and hates them. He had bubbles in the tires and it cost him $800 to replace a couple of them.

From what I have read, run-flats are considerably improved in ride, and some are better than others. No telling about the ATS run-flats. I'll test drive and see.

I have mixed emotions about the run-flats. Certainly they are safer if you get a flat on a highway. Waiting for AAA on a lonely road at night isn't fun. Good for the wife, teenager, etc.

The alternative is no better. The trouble with the ATS is that there is no space for a compact spare. The Base gives you a can of fix-a-flat. No way that I would feel confident taking a long trip with a can of fix-a-flat.

gohawks63
09-14-12, 10:35 PM
My CTS Coupe has the air pump with the sealant. My wife has run flats on her BMW X5. We haven't had it that long to form an opinion, but it definitely has a firmer ride, although I don't know whether to attribute it to the RFTs or the vehicle's suspension. .

rchern
09-14-12, 11:12 PM
Cadillac's website states that run flats can go up to 50 miles with a puncture. Let's say you go away for a weekend and you're a few hundred miles from home and you start back home Sunday afternoon and after an hour or so you puncture a tire. What are you going to do? I'm sure everyones been up in the mountains or in the desert and it's not like there's a Cadillac dealer every 20 or 30 miles or so. You may not even find a town for 50 miles, then you have to get a room and hope there's tire dealer and if there is they probably don't stock them.....and on and on, you get my drift. You can go a hell of a lot longer on a donut. I don't like the idea of them for that reason and plus I've never heard any thing good about them for the same reasons already posted. Also, will wheels made for run flat tires accept regular tires if you wanted to change them? I did hear some manufacturers did address some problems people were complaining about so hopefully there's some newer better ones on Caddy's.

jurzdevil
09-14-12, 11:39 PM
You can probably lose 50-100 pounds of weight too by going to back to regular tires.

bmw2caddy
09-15-12, 03:21 AM
If the TPMS warning turns on because of a puncture etc... You don't have to be near a dealer if you put air in the tire you'll be fine. Yes you'll continue to lose air but if for some reason you're some extreme distance from home/dealer etc. you just have to reinflate when you get the warning. The 50 miles they say you can drive with a puncture is if you do nothing about it.

And yes the wheels will accept regular tires.

gohawks63
09-15-12, 08:10 AM
Cadillac's website states that run flats can go up to 50 miles with a puncture. Let's say you go away for a weekend and you're a few hundred miles from home and you start back home Sunday afternoon and after an hour or so you puncture a tire. What are you going to do? I'm sure everyones been up in the mountains or in the desert and it's not like there's a Cadillac dealer every 20 or 30 miles or so. You may not even find a town for 50 miles, then you have to get a room and hope there's tire dealer and if there is they probably don't stock them.....and on and on, you get my drift. You can go a hell of a lot longer on a donut. I don't like the idea of them for that reason and plus I've never heard any thing good about them for the same reasons already posted. Also, will wheels made for run flat tires accept regular tires if you wanted to change them? I did hear some manufacturers did address some problems people were complaining about so hopefully there's some newer better ones on Caddy's.

That's a good point. Now our X5 has a donut too, so I guess in my case the run flat gives you a bit more time to get to a safer place to change your tire so you're not on the side of the expressway, but I get that not all cars come equipped that way.

concorso
09-15-12, 10:23 AM
run-flats are considerably improved in ride Versus older run-flats, or versus regular tires? Every run-flat Ive been on has had a horrible ride.

JimmyH
09-16-12, 05:19 PM
The problem with compact spares (or any spare) is that almost everyone neglects them and when the time comes that it is needed, it's flat.

The only time you really one is if you have a blowout. If you just get a puncture, you can fill the tire to 45psi and that should easily get you 30-40 miles.

Fraggy
09-17-12, 03:10 AM
Versus older run-flats, or versus regular tires? Every run-flat Ive been on has had a horrible ride.

Old, new, they all still suck. I'm in a BMW three series with the newest Goodyear efficient grip runflats. they have very little feedback and are very hard when inflated well, if you inflate them lesser, they are very wobbly and unstable.

frankc5r
09-17-12, 09:00 AM
Old, new, they all still suck. I'm in a BMW three series with the newest Goodyear efficient grip runflats. they have very little feedback and are very hard when inflated well, if you inflate them lesser, they are very wobbly and unstable.

My other car is a 10 Corvette GrandSport which came with GoodYear runcraps. They are HORRIBLE. Noisy, ride hard, terrible in rain but ok
on a smooth road but where is one of those in MI. I replaced them in the 1st 500 mi with Michelins non runflats and carry a can of sealer and a small portable compressor.
frank

rchern
09-17-12, 04:14 PM
I don't know why Cadillac would start puting run flats on cars when so many people have complained about them for so many different reasons (ride,handling,noise)since they came out. Since Cadillac monitors this forum I would suggest that since Cadillac wants the ATS to compete with the BMW 3 series that they search BMW forums and read some of the problems and experiences people have with them. Some people actually took them off after a couple thousand miles and replaced them with regular tires. Some people said they wouldn't buy another BMW if it came with run flats.

AtlantaGuy00
09-17-12, 06:42 PM
Are all of the tires on the 18" wheels run flats?

marktanner
09-17-12, 10:00 PM
The only ATS to have regular tires is the base car with 17s. All of the others have run-flats. This may not be a big problem any more, though. Reviews of the new 3 series have praised the ride, and they all have run-flats. All of the reviews for the ATS have also praised the ride, and all of the tested vehicles have had run-flats. Apparently, the current generation of run-flats have improved a lot in the ride department. Don't expect a great ride on 19s, though. Heavier wheels with shorter sidewalls don't ever help the ride, especially if the car isn't designed for it. They also tend to make it accelerate slower and use more gas; that's just physics.

I"ve seen two ATS's so far, a red Luxury 2.5 with 17s, and a Black Diamond Premium 3.6 with 18s. IMO, they both looked good. Remember, the current M3 has 18s standard, and no one complains about those looking tiny. My old 1993 M5 came with 17s, and those were the largest wheels available at the time. My current CTS-V does have 19s, but those are necessary to clear the calipers on the giant 15 inch brake discs that are necessary to stop 4300 pounds. The much lighter ATS has smaller brakes, and probably doesn't even need the 18s for any performance benefit. IMO, it's just for fashion, though at least it's engineered to handle the 18s. I'm actually pleased that Cadillac hasn't offered 19s on these cars, as it would probably ruin the ride/handling balance just for fashion. A lot of BMW's complaints come from those with larger wheels; poorer ride doesn't compare to the damaged wheels resulting from sidewalls that are too short for our increasingly crappy roads. Just my opinion, of course.

MikeTerp
09-20-12, 07:37 PM
Go to any of the BMW forums for a COMPLETE, exhaustive, end-to-end discussion of runflats. You will get every conceivable opinion and story - most of them negative. While the biggest "benefit" claimed by some is safety (not having to change tires in the middle of the night, etc), others point out correctly that if you have a flat in the boondocks, you may not be able to make it to any tire store - AND, if you can, they are not likely to have a replacement, so you could either be stuck waiting for who knows how long, or end up buying a regular tire to get you home. I had the latter experience on a 2007 328. The original tires were Bridgetone EL-42's (utter crap), and the dealer swapped them out at 8K miles for Conti's - much better, but hard-riding and noisy. Most BMW enthusiasts would trade their RFTs in a heartbeat for a space-saver spare. I ended up ditching my RFTs at 30K miles (22K out of the Contis) for some "go flat" Michelin Pilot Exaltos and a can of fix-a-flat. Best move I ever made with that car. Noise, ride, and handling all improved markedly. Beyond their availability, the other issue with RFTs is selection and price. They are consistently more expensive than conventional tires.

Now, some people don't mind any of this, but most of the BMW enthusiasts do. There are no shortage of opinions. I am very serious about a new ATS but cringe at the thought of having to drive it on RFTs. Just my two cents.

rchern
09-20-12, 10:53 PM
I don't understand why Cadillac went with tires that are so controversial and have so many complaints about them. If their answer is trunk space I can show everyone how Cadillac wasted a lot of trunk space. I had a CTS sedan and the trunklid was attatched to the bodywork with a strut so it did not protrude into the trunk. Then, I got a CTS coupe and they used a different type of hinge that protrudes into the trunk taking up valuable space. You pack your trunk full of stuff and then when you try to close the trunk you can't because of the hinge. You can only fit something shallow under the hinge. On the ATS they used the same kind of hinge that they used in the coupe but they enlarged the wheelwell covering so it encompasses the hinge so therefore you have no room under the hinge. If you google "CTS sedan trunk photo", then "CTS coupe trunk photo" then "ATS trunk photo" you will see the progression which leads me to believe that they don't want a donut or even a pump because they have so little trunk space.

investor74
09-21-12, 12:12 AM
rchern - you are absolutely right. My Catera has struts mounted at the top of the trunk and they take up no trunk space at all. The Catera even has a full size spare. You close the lid, and nothing touches your luggage.

All cars seem to have the space-robbing hinges these days instead of struts. The thing that I can't understand about the ATS is that the the hinge enclosures seem to be overkill. The enclosures are there to protect the items in the trunk when you close the lid. But in the ATS, the enclosure intrude into the trunk so much that they take up a couple extra cubic feet.

Fraggy
09-21-12, 09:45 AM
Go to any of the BMW forums for a COMPLETE, exhaustive, end-to-end discussion of runflats. You will get every conceivable opinion and story - most of them negative. While the biggest "benefit" claimed by some is safety (not having to change tires in the middle of the night, etc), others point out correctly that if you have a flat in the boondocks, you may not be able to make it to any tire store - AND, if you can, they are not likely to have a replacement, so you could either be stuck waiting for who knows how long, or end up buying a regular tire to get you home. I had the latter experience on a 2007 328. The original tires were Bridgetone EL-42's (utter crap), and the dealer swapped them out at 8K miles for Conti's - much better, but hard-riding and noisy. Most BMW enthusiasts would trade their RFTs in a heartbeat for a space-saver spare. I ended up ditching my RFTs at 30K miles (22K out of the Contis) for some "go flat" Michelin Pilot Exaltos and a can of fix-a-flat. Best move I ever made with that car. Noise, ride, and handling all improved markedly. Beyond their availability, the other issue with RFTs is selection and price. They are consistently more expensive than conventional tires.

Now, some people don't mind any of this, but most of the BMW enthusiasts do. There are no shortage of opinions. I am very serious about a new ATS but cringe at the thought of having to drive it on RFTs. Just my two cents.

I agree wholeheartedly!

concorso
09-24-12, 11:59 AM
Cadillac, make RFT's options, not standard items. If I have to spend $1000+ immediately on top of the purchase of the car just to get a set of good tires, Im not going to be a happy camper.