Driveguard Runflats on a Model 3

[TomB985]

Hi, everyone.

After 29K my factory Michelin's were about done. I had about 2.5/32nds on all of them, and with regular rotation they wore quite evenly. Not much to complain about with them, and I was pleased they lasted this long with my driving style.

I've always been concerned about the lack of a spare tire, and a medical condition has gotten worse making it extremely hard for me to walk. So dealing with a flat tire is a bit beyond me at the moment. So despite a lackluster experience from years ago with RFPs, I pulled the trigger on a set of Bridgestone Drive guards at Costco. With a $150 rebate they came to about $820 with installation, and carry a 50K treadlife warranty. The big downside to RFP tires comes with the compromise necessary for the stiffer sidewalk. These things are heavy at 30 pounds each, compared to 24 pounds for the factory rubber. The stiffer sidewall won't flex as much over bumps, and the rigged pattern exists to coolest sidewalls when running without air. These things are supposed to be capable of operating for up to 50 miles at 50 mph without air, which is something I hope to never test.

I had a 52-mile drive home after the install, and I was pleasantly impressed with the ride. Handling seemed similar, but seemed to feather a bit accelerating around corners. The outside temperature was 32°, and I expect this would be better in warmer temperatures. There was noticeably less road noise though, in the ride quality didn't seem to suffer much at all. I could feel the extra unsprung weight of bit over undulating pavement, but only when I was paying attention for it. Overall the decreased road noise seems to outweigh the slightly rougher ride, so I'm pretty happy with the swap. I'll keep this thread updated as time goes on, hopefully get at least 40 K out of them. If not I will discover how well they handle their tradelife warranty.

 

[jjrandorin]

I had those tires (OEM) on my 435, and unfortunately did get a chance to test their ability to drive when they were flat, almost 40 miles. They worked fine for that. I like the PS4S tires on my model 3P better, but as far as runflats go they were not bad... at least on the BMW.

 

[oreobbq]

Couldn't edit the post in time, and dictation failed me. 29,000 miles, not 209K...I don't drive THAT much!

As much as I like the idea of run flats I'd keep uhp tires year round weather permitting.

(moderator note: edited post to remove quoted mis typed text as I corrected it for OP)

 

[TomB985]

Been trying to figure out what you were trying to say. Maybe you got interrupted lol. As much as I like the idea of run flats I'd keep uhp tires year round weather permitting.

Whoopsie!

I have a severe hand disability, so mouse and keyboard use really suck. Dragon is usually pretty good at scrawling down what I’m trying to say, but not always. “There was noticeably less road noise.”

Wish that edit button was still there.

(moderator note: made correction)

 

[TomB985]

Not sure which moderator fixed my post, but a big thanks for the correction. I'll do better job proofreading this time.

After putting more miles on different types of roads, I'm pleased with how they ride. They feel just a bit stiffer than the factory rubber, but not overly so. Handling seems very similar, which makes sense given the stiffer sidewall Tesla specs for the factory tires. I'm sure the drive guards take that stiffness to a whole new level, but the car seems planted right up to the limit. With a similar treadlife warranty I expect them to last about as long, but reviews from other sites suggest they may be more susceptible to pothole damage. I remember my mom had these tires recently on her minivan and lost one to pothole damage on some rough New Hampshire back roads. Her van is just a bit heavier than the 3 which has a much stiffer suspension, so this is certainly a concern. I imagine I'm less likely to bend a rim, though.

At any rate, Cosco has road hazard insurance is included with tire installation, so it shouldn't be too pricy if I poke a hole in one.

 

[TomB985]

I just noticed a few minutes ago that the sidewalls of the Driveguard 235/45R18 extend past the rim. It's nice to finally have a bit of curb protection.

 

[ianc]

Be interested to know how the efficiency compares. Let us know when you run some miles on them.

 

[JCtx]

I have a few comments about runflats. I personally think they provide a false sense of security, but to each his own. First of all, a runflat tire is going to collapse in A LOT less than 50 miles when deflated, especially on a 2+ ton heavy car like the M3; hope you never have to find out I'm correct . Second of all, the tire would be ruined even with just a few miles running deflated. No shop would fix one anyway, and good luck finding a replacement tire in stock. Third of all, most runflats require a special machine to mount/dismount, so if you get a flat away from a big city, good luck getting back on the road (due to no tire and no machine to change it). And fourth of all, they're super heavy, and on an EV, they probably have a significant impact on efficiency, especially on the highway. Not to mention they're more expensive too, have a harder ride, and all other detractions. Bottom line for me is unless you live in the Bronx, and work at night, where your life would depend on not getting stranded, I'd skip them.

When i had RF tires, I always treated them like a regular tire, meaning using a flat tire repair kit, so I didn't ruin them. After having them once, I replaced them immediately on my Corvettes, which were the only vehicles I bought that had them. It's better to carry a flat tire repair kit and a compressor (which I did even with RFs), and make sure you have roadside assistance, in case that kit is not enough, for some reason. I haven't gotten stranded with a flat tire in my 59 years, so it's not a common occurrence while traveling. Just watch where you tread . Flats typically happen on construction zones, where it's easier to deal with them.

 

[TomB985]

I have a few comments about runflats. I personally think they provide a false sense of security, but to each his own. First of all, a runflat tire is going to collapse in A LOT less than 50 miles when deflated, especially on a 2+ ton heavy car like the M3; hope you never have to find out I'm correct . Second of all, the tire would be ruined even with just a few miles running deflated. No shop would fix one anyway, and good luck finding a replacement tire in stock. Third of all, most runflats require a special machine to mount/dismount, so if you get a flat away from a big city, good luck getting back on the road (due to no tire and no machine to change it). And fourth of all, they're super heavy, and on an EV, they probably have a significant impact on efficiency, especially on the highway. Not to mention they're more expensive too, have a harder ride, and all other detractions. Bottom line for me is unless you live in the Bronx, and work at night, where your life would depend on not getting stranded, I'd skip them.

When i had RF tires, I always treated them like a regular tire, meaning using a flat tire repair kit, so I didn't ruin them. After having them once, I replaced them immediately on my Corvettes, which were the only vehicles I bought that had them. It's better to carry a flat tire repair kit and a compressor (which I did even with RFs), and make sure you have roadside assistance, in case that kit is not enough, for some reason. I haven't gotten stranded with a flat tire in my 59 years, so it's not a common occurrence while traveling. Just watch where you tread . Flats typically happen on construction zones, where it's easier to deal with them.

I appreciate your comments, but think a lot of things are exaggerated.

I also have previous experience with runflats, but mine involved an AWD minivan that's about 1,100 lbs heavier than my M3. These cars aren't as heavy as people think; my SR+ weighs 3650 pounds. That's only a couple hundred more than a Lexus GS. The XL-spec tires are rated for 1,650 pounds per tire, which is only 100 pounds less than the 235/55R18 tires on the minivan. And I've seen those tires run more than 50 miles completely empty with a gash in the sidewall. So why would a tire with only 100 pounds extra capacity had no trouble getting 800 pounds more minivan down the road than they would on my 3?

A few years ago when the Driveguard was released, Consumer Reports tested them around their track without air. They seemed pleased with how they handled.

So no, I don't buy the idea that they won't hold up limping to a tire shop without air. My mom has done this a couple times with her minivan without issue, and we never had a problem with the runflats on our 2011 Sienna. The Driveguard is a new or tire than the Turanzas those vans originally came with, but don't expect they would perform any worse. Especially on a car weighing more than a thousand pounds less.

I'm sure they won't be repairable if I run them without air, which is why I had them installed at Costco with their included road hazard protection. There's certainly an added cost to running these, but I'm happy to deal with their downsides for the safety benefit. I have a serious hand/foot disability, and I just can't deal with a flat like I used to.

 

[TomB985]

It is too soon to get conclusive data, but after a month and 1000 miles it looks like my efficiency is nearly identical to what I got with the OEM Michelins.
OEM tires last year:

Driveguards 1/29-present

Factory Michelins:

 

[GoodKarma]

It is too soon to get conclusive data, but after a month and 1000 miles it looks like my efficiency is nearly identical to what I got with the OEM Michelins.
OEM tires last year:

Driveguards 1/29-presentView attachment 642649
Factory Michelins: View attachment 642655

@TomB985 - would greatly appreciate it if you could share updated experience (and, if possible, the stats) with the Driveguards. Any change in your recommendation? Thank!

 

[jackmott]

The runflats on the C5 Z06 Corvettes were pretty great. We would set decent autocross times on them. Maybe ultra wide tires make runflats more feasible or something.

 

[andy00778]

It is too soon to get conclusive data, but after a month and 1000 miles it looks like my efficiency is nearly identical to what I got with the OEM Michelins.
OEM tires last year:

Driveguards 1/29-presentView attachment 642649
Factory Michelins: View attachment 642655

Can you update us on how these drive guards are working for you, including efficiency? I’m considering them for my M3 when the time comes. Have them on my Volt for past 3 years and I did notice some efficiency drop, most noticeable when the tires were new ( normal)

 

[TomB985]

Can you update us on how these drive guards are working for you, including efficiency? I’m considering them for my M3 when the time comes. Have them on my Volt for past 3 years and I did notice some efficiency drop, most noticeable when the tires were new ( normal)

I wish I could, but I sold the car in June, 2021. The tires had 5,000 miles on them, and I never noticed much of a difference between them and the factory Michelins.

 

[PianoAl]

The big downside to RFP tires comes with the compromise necessary for the stiffer sidewalk. These things are heavy at 30 pounds each, compared to 24 pounds for the factory rubber.

Lighter than a spare.

General question: If you drive on them with no air, say 40 miles, are they ruined or good as new?

 

[JCtx]

You wouldn't reach 40 miles on RFs; they'd collapse before, especially with a heavy car like the M3. And THAT is the problem with RFs; they provide a false sense of security. And even after rolling them deflated for a few miles, they'd be ruined. Unless you work at the Bronx at night, and your life depends on not having a flat, you're MUCH better off with regular tires, and just carry a flat tire kit and compressor. I always treated my RFs like regular tires before dumping them, meaning if I got a flat, I'd immediately patch it upon TPMS flashing a warning, to avoid ruining them. And the additional problem is many small city tire shops don't have the equipment able to handle them. Nor would they carry them, so I don't understand why manufacturers still use them.

 

[TomB985]

You wouldn't reach 40 miles on RFs; they'd collapse before, especially with a heavy car like the M3.

That’s just not true. Runflat tires are rated at their max operating capacity.

They don’t survive being used without air, but they will get you there.

 

[arekux]

Never liked RF on my bmws, they always ride worse. I just carry tire repair kit and air pump.