[4sallypat]

My 2018 Clarity factory OEM tires (Michelin green LRR) at 36,000 miles is not looking good for longevity.

Even with rotations every 10K, I am not happy with the treadwear.
Also unhappy that I had to wait for a tow truck when one tire blew (mobility compressor was useless) last year.
Although I had the tire protection and had it replaced which paid for the insurance - the inconvenience was the big factor.

Now I am looking at getting run flat tires (RFT) to replace the OEM tires.
The reason for run flats is that you can drive for up to 50 miles at 50MPH on a flat tire without worrying about wheel damage.
I have had RFT on all my BMWs for the past 20 years so I know how helpful that can be if you had to drive on a flat tire to a shop.

Using the factory OEM size of 235-45x18 I only find one RFT: Bridgestone DriveGuard at $220 each - which by the way, is the same exact brand I use on my current BMW 5 sedan....

Then going up a size to 245-45-18 (.5" taller and .5" wider) I can find tons of RFT options - over 20 options.
Looking at the Pirelli Winter Sottozero they are priced a bit better ($190 ea).

Although I live in a dry, hot climate - the appeal of a winter RFT harkens my memory to the days I used to go winter skiing and the high silica content tires gripped the snow and ice very well...

I don't know which to choose: AS factory sized RFT or Winter +1 sized RFT....

Any ideas / suggestions / comments ?

 

[fotomoto]

Then going up a size to 245-45-18 (.5" taller and .5" wider) I can find tons of RFT options - over 20 options.

Would these sizes mess with the TPMS that reads tire size instead of PSI? Or does the recalculate feature handle this?

 

[2002]

Would these sizes mess with the TPMS that reads tire size instead of PSI? Or does the recalculate feature handle this?

The Clarity TPMS reads wheel rotation speed. When you calibrate it measures the rotation speed of all four wheels, then later if one wheel is rotating differently it interprets that as being due to low tire pressure.

With runflats I suspect that the Clarity TPMS would not recognize that a tire has lost pressure because the rotation speed probably won't change much. Probably would need an add-on tire pressure monitor. I got one because of false alarms on the TPMS, and also because Clarity TPMS doesn't tell you which tire is low. They make ones that sit on top of the dash, but I wanted something less obtrusive, the one I got is made by Tymate and plugs into the 12V.

 

[EV Nerd]

The Clarity TPMS reads wheel rotation speed. When you calibrate it measures the rotation speed of all four wheels, then later if one wheel is rotating differently it interprets that as being due to low tire pressure.

With runflats I suspect that the Clarity TPMS would not recognize that a tire has lost pressure because the rotation speed probably won't change much. Probably would need an add-on tire pressure monitor. I got one because of false alarms on the TPMS, and also because Clarity TPMS doesn't tell you which tire is low. They make ones that sit on top of the dash, but I wanted something less obtrusive, the one I got is made by Tymate and plugs into the 12V.

View attachment 780

View attachment 781

I'm surprised that the "rotation-delta-method" for tire pressure can be used in the presence of other systems that also use comparative rotation speeds as triggers, like ABS, traction control and stability programs. Perhaps the pressure-sensing software looks for long-term differences, while the others are looking for more transient effects? (That's probably a question more for the engineers that implement these systems, but I like to speculate and problem-solve.)

 

[EV Nerd]

The Clarity TPMS reads wheel rotation speed. When you calibrate it measures the rotation speed of all four wheels, then later if one wheel is rotating differently it interprets that as being due to low tire pressure.

With runflats I suspect that the Clarity TPMS would not recognize that a tire has lost pressure because the rotation speed probably won't change much. Probably would need an add-on tire pressure monitor. I got one because of false alarms on the TPMS, and also because Clarity TPMS doesn't tell you which tire is low. They make ones that sit on top of the dash, but I wanted something less obtrusive, the one I got is made by Tymate and plugs into the 12V.

View attachment 780

View attachment 781

I just ordered one of these from Amazon. The reviews on this one are hit and miss, but I took a chance anyway, wanting to see battery voltage and temperatures that aren't on the other branded, round ones. I'll follow up with results when it arrives.

Thanks for sharing!

 

[ClarityDave]

I'm surprised that the "rotation-delta-method" for tire pressure can be used in the presence of other systems that also use comparative rotation speeds as triggers, like ABS, traction control and stability programs. Perhaps the pressure-sensing software looks for long-term differences, while the others are looking for more transient effects? (That's probably a question more for the engineers that implement these systems, but I like to speculate and problem-solve.)

Yeah, it’s either gotta be a long term thing or it takes into account other variables like turning a corner. Roughly, if a car is in a 50-foot radius turn (100-foot diameter circle) and the distance from the inside tire to the outside tire is about six feet, then the outside tire is making a 50-foot radius arc while the inside tire is making a 44-foot radius arc. That means one wheel is turning about 15% faster than the other.

 

[EV Nerd]

Yeah, it’s either gotta be a long term thing or it takes into account other variables like turning a corner. Roughly, if a car is in a 50-foot radius turn (100-foot diameter circle) and the distance from the inside tire to the outside tire is about six feet, then the outside tire is making a 50-foot radius arc while the inside tire is making a 44-foot radius arc. That means one wheel is turning about 15% faster than the other.

And it's going to be a slightly different delta for the fronts (which turn) as it will for the rears (which don't). I bet that's a fun problem to solve. (Not being sarcastic. I'm an engineer, too.)

 

[2002]

I'm surprised that the "rotation-delta-method" for tire pressure can be used in the presence of other systems that also use comparative rotation speeds as triggers, like ABS, traction control and stability programs.

My guess is that the same sensor is providing the same rotational data to all of these systems, and each system uses the data whenever and however often it needs it.

And it's going to be a slightly different delta for the fronts (which turn) as it will for the rears (which don't).

Assuming it can tell from other sensors when the car is going straight as opposed to being in a turn, I would think the TPMS system only looks at rotational data during those periods.

 

[2002]

I just ordered one of these from Amazon. The reviews on this one are hit and miss, but I took a chance anyway, wanting to see battery voltage and temperatures that aren't on the other branded, round ones. I'll follow up with results when it arrives.

Thanks for sharing!

Had it a few months and seems to be working well. Being the first time I have used one of these the installation took longer than I thought. Getting it to synchronize for the first time was a little confusing, but reading the manual combined with trial and error, as well as giving it enough time to synchronize, it eventually got sorted out. Also the installation of the sensors onto the valve stems is a bit tricky the first time you do it, mainly related to the rubber sleeve that covers the gap between the sensors and the valve stems. The rubber sleeve seemed to get in the way during installation, but with some practice I finally got used to it by the time I did the fourth tire LOL. Some people say they don't even use the rubber sleeves, but I think they serve a purpose so it's worth the effort to figure out how to get them installed with the sleeves.

Next time I rotate my tires I have to decide whether to reprogram the sensors to their new location, or remove each sensor and reinstall it at the location where it was previously. Reprogramming isn't that hard to do so I will probably go that route.

The disconcerting thing about all of the systems that I looked into is they all seem to say that they may not immediately report a drop in pressure, it may show up only over time. Not great if you hit a nail and have fairly rapid pressure loss. I suspect they are just covering their tracks by saying that and it may respond quicker than they make it sound, but no real way to know. But presumably the built in TPMS system will give you a warning about a sudden pressure loss.

 

[4sallypat]

The Clarity TPMS reads wheel rotation speed. When you calibrate it measures the rotation speed of all four wheels, then later if one wheel is rotating differently it interprets that as being due to low tire pressure.

With runflats I suspect that the Clarity TPMS would not recognize that a tire has lost pressure because the rotation speed probably won't change much. Probably would need an add-on tire pressure monitor. I got one because of false alarms on the TPMS, and also because Clarity TPMS doesn't tell you which tire is low. They make ones that sit on top of the dash, but I wanted something less obtrusive, the one I got is made by Tymate and plugs into the 12V.

View attachment 780

View attachment 781

Very cool!

On my BMWs, the run flat tires do show a "sag" or slight flat looking profile when the air is gone, but the sidewalls are stiff enough to hold up the car to drive a limited distance which is what I really wanted.

Will report back on which RFT I decide to get...

 

[EV Nerd]

Had it a few months and seems to be working well. Being the first time I have used one of these the installation took longer than I thought. Getting it to synchronize for the first time was a little confusing, but reading the manual combined with trial and error, as well as giving it enough time to synchronize, it eventually got sorted out. Also the installation of the sensors onto the valve stems is a bit tricky the first time you do it, mainly related to the rubber sleeve that covers the gap between the sensors and the valve stems. The rubber sleeve seemed to get in the way during installation, but with some practice I finally got used to it by the time I did the fourth tire LOL. Some people say they don't even use the rubber sleeves, but I think they serve a purpose so it's worth the effort to figure out how to get them installed with the sleeves.

Next time I rotate my tires I have to decide whether to reprogram the sensors to their new location, or remove each sensor and reinstall it at the location where it was previously. Reprogramming isn't that hard to do so I will probably go that route.

The disconcerting thing about all of the systems that I looked into is they all seem to say that they may not immediately report a drop in pressure, it may show up only over time. Not great if you hit a nail and have fairly rapid pressure loss. I suspect they are just covering their tracks by saying that and it may respond quicker than they make it sound, but no real way to know. But presumably the built in TPMS system will give you a warning about a sudden pressure loss.

Installed mine, and it worked without any extraordinary interventions on my part. I left the default settings for alarms, because my usual pressure is 38psi, which is close to the center of the default range. I am disappointed that I can't change temperature units to F, and it's difficult to see the display. It needs to be much brighter.

 

[2002]

Installed mine, and it worked without any extraordinary interventions on my part. I left the default settings for alarms, because my usual pressure is 38psi, which is close to the center of the default range. I am disappointed that I can't change temperature units to F, and it's difficult to see the display. It needs to be much brighter.

I don't remember if there is a brightness setting but I don't think so. For me the brightness is okay since it's in the shade. I knew the visibility would be a little awkward, I have to tilt my head down a little to see it, but I prefer having it out of the way rather than having one sitting on my dashboard. I suppose a 12V extension cord would enable moving it closer, but so far I am okay with it where it is. Yeah a common complaint is not being able to set the temperature to Fahrenheit. Maybe I'll actually use it as a reason to start thinking in Celsius. But probably not LOL.

 

[EV Nerd]

I don't remember if there is a brightness setting but I don't think so. For me the brightness is okay since it's in the shade. I knew the visibility would be a little awkward, I have to tilt my head down a little to see it, but I prefer having it out of the way rather than having one sitting on my dashboard. I suppose a 12V extension cord would enable moving it closer, but so far I am okay with it where it is. Yeah a common complaint is not being able to set the temperature to Fahrenheit. Maybe I'll actually use it as a reason to start thinking in Celsius. But probably not LOL.

I considered one of their other models that would sit real well on the top left edge of the console, but figured I only really needed it for the occasional check before long trips, for the audible alarms and to help tell which specific tire is low if the Clarity itself alarms. All of these needs would be satisfied if I simply pulled over (I would anyway) and had a better look.

Yeah, I've fallen out of practice with the "feel" for Celsius I got teaching high school Physics for twenty years. I still convert from m/s to miles/hour by doubling the m/s number. It's close enough for "feel". I got really good at reading stuff upside down too, but am not nearly as good at that any more, either. I retired seven years ago. Loved what I did, but never looked back.

 

[mhaynes]

My 2018 Clarity factory OEM tires (Michelin green LRR) at 36,000 miles is not looking good for longevity.

Even with rotations every 10K, I am not happy with the treadwear.
Also unhappy that I had to wait for a tow truck when one tire blew (mobility compressor was useless) last year.
Although I had the tire protection and had it replaced which paid for the insurance - the inconvenience was the big factor.

Now I am looking at getting run flat tires (RFT) to replace the OEM tires.
The reason for run flats is that you can drive for up to 50 miles at 50MPH on a flat tire without worrying about wheel damage.
I have had RFT on all my BMWs for the past 20 years so I know how helpful that can be if you had to drive on a flat tire to a shop.

Using the factory OEM size of 235-45x18 I only find one RFT: Bridgestone DriveGuard at $220 each - which by the way, is the same exact brand I use on my current BMW 5 sedan....

Then going up a size to 245-45-18 (.5" taller and .5" wider) I can find tons of RFT options - over 20 options.
Looking at the Pirelli Winter Sottozero they are priced a bit better ($190 ea).

Although I live in a dry, hot climate - the appeal of a winter RFT harkens my memory to the days I used to go winter skiing and the high silica content tires gripped the snow and ice very well...

I don't know which to choose: AS factory sized RFT or Winter +1 sized RFT....

Any ideas / suggestions / comments ?
View attachment 778
View attachment 779

I just installed some Pirelli tires for the first time (I've never owned Pirellis before) and love them. I got the P7 Cinturato All Season +2 in the original size....just $688 delivered from Tire Rack. Could not be happier!

 

[4sallypat]

I just installed some Pirelli tires for the first time (I've never owned Pirellis before) and love them. I got the P7 Cinturato All Season +2 in the original size....just $688 delivered from Tire Rack. Could not be happier!

Pirellis are great tires! Built for performance - I remember them on my first BMW (before they went to RFT).

I am getting ready to replace the OEM tires with the winter rated Pirelli Sottozero RFT so that I don't have to worry about carrying a mobility kit or spare...

 

[jzchen]

Err. I hope someone convinced you not to get winter tires in a hot locale? Anyways the reason for my post. BMWs have special wheels with EH2 + (or plain EH2) humps on the wheels. These humps help hold the bead in place and make 100 mi on a flat runflat possible. At this distance, even at 50 mi on regular wheels, the tire is toast/needs replacing....

 

[jzchen]

@4sallypat I was searching through tire options and was trying to figure out a list of tires that offer some level of curb rash protection, to pretty much no avail. I could have sworn TireRack put it in their description but I checked many to no avail.

My next choice is RunFlats no question, but kind of bummed at being limited to only one choice, I went to the Bridgestone website to try to glean more details on the Driveguards. While there I noticed something new that seems to be just coming out, a Driveguard Plus, vs the older Driveguard Driveguard. (Go figure they add a second "Driveguard"). The Plus version includes enhanced snow performance via 40 ft shorter stopping distance vs the previous version, the caveat being they don't have 235/45RF18. They do have 245/45RF18 which is what you noted considering. Remembering your wish for improved snow performance I thought I'd bump this thread...

Did you end up getting replacement tires already? I haven't found the 245/45RF18 Plus version for sale yet....

 

[4sallypat]

@4sallypat I was searching through tire options and was trying to figure out a list of tires that offer some level of curb rash protection, to pretty much no avail. I could have sworn TireRack put it in their description but I checked many to no avail.

My next choice is RunFlats no question, but kind of bummed at being limited to only one choice, I went to the Bridgestone website to try to glean more details on the Driveguards. While there I noticed something new that seems to be just coming out, a Driveguard Plus, vs the older Driveguard Driveguard. (Go figure they add a second "Driveguard"). The Plus version includes enhanced snow performance via 40 ft shorter stopping distance vs the previous version, the caveat being they don't have 235/45RF18. They do have 245/45RF18 which is what you noted considering. Remembering your wish for improved snow performance I thought I'd bump this thread...

Did you end up getting replacement tires already? I haven't found the 245/45RF18 Plus version for sale yet....

Yes, ordered a set of RFT winter tires from America's Tire - waiting for the backorder to be filled - apparently the east coast folks are still buying them up and I have to wait until they slow down as they will be trucked cross country (I am in California).

The best curb protection tires I can find are Yokohama Envigor or the Continental Winter Contact:

 

[2002]

I was searching through tire options and was trying to figure out a list of tires that offer some level of curb rash protection, to pretty much no avail.

Interestingly myself and at least one other person noticed that when we had a tire replaced on our Clarity with the exact same Michelin Energy Saver A/S 235/45R18 94V, the replacement tire has a different shape near the rim, including a small ridge, or what I would call a chine. And the rubber near the bead sticks out a bit from the rim more like what I would consider a normal tire, making it much more resistant to curb rash than the version of the tire that came with the car. The original version has a very flat shape and the rubber near the bead is nearly flush with the rim.

One theory is that Michelin made a change to the tire midstream. However another theory is that there is a slight difference between the OEM version of this tire and the retail version. Perhaps the OEM version is a little cheaper. But I wonder if it's also because a flat tire tends to look slightly better on the showroom floor than a "bulgy" tire.

I got my replacement tire at Costco, I'm pretty sure the other person got theirs at a tire store. If you have a chance to look at the Michelin Energy Saver A/S 235/45R18 in a tire store you can probably see the difference, although you have to first "memorize" how your OEM tire looks. It's easier for me because the two tires are a few feet away from each other on my car, the visual difference is quite apparent once you are looking for it.

Not to say I plan to get these tires again, I'm just pointing it out as an explanation for why so many people have such a problem with curb rash on the Clarity. And if you have to replace a tire on the Clarity, make sure that the replacement tire is the bulgy version not the flat version.

If anyone has replaced a tire on their Clarity, check it out and see if the replacement has a different shape near the rim.

 

[jzchen]

If you do go with 245/45R18 I'm glad you chose America's Tire because any issues they'll give you a full refund/credit towards another set. I got a replacement oversize spare and it would not sit in the trunk well flush so I exchanged it, full credit AND no loss of installation fee. I was sure they'd at least charge me a new install fee...

My OE wheels are curb rashed to hell. Not on purpose... I did not know about the special sound deadening insert that Honda engineers built into each wheel. I asked around the two main wheel repair companies Wheels America and Wheel Collision Center and they both say they remove them. They aren't replaceable. ONLY Honda wheels have these devices my original plan was to get light aftermarket wheels. But my son and I notice a quietness (they work, upon careful observation) that my wife's Porsche Panamera doesn't even have. So I will be completing a set of the Clarity accessory wheel option. (I currently have one just in case my wife got a flat on her trip to Las Vegas. And one America's Tire in Norwalk has/had a Driveguard in stock). I will try to install Rim Ringz. I ordered the yellow 18" rings 1 1/2 weeks ago on Saturday. They are a company in Los Angeles, their website says they ship within 48 hours (business days I assume) but contacting them I was told they would be shipped this last Saturday. Still waiting...