Adding TPMS to a Roadster

[Papa]

I posted in my build thread that I'll be replacing my 17" wheels/tires with 18". I'm looking at Michelin Pilot Sport PS2 tires, which are now only available as Run Flats. I found some non Run Flats available in the smaller front size, but was told they are discontinued. I actually like the idea of RFTs on the roadster, but now I have a question about adding TPMS. RFTs really should be run with TPMS to alert the driver of a pressure loss. There are plenty of retrofit kits out there, but I wanted to see if anyone else has experience with a kit that they like. I'd like to have something that is reliable, and doesn't look like junk. I'd prefer the standard inside the wheel sensors over the cap sensors. Any recommendations would be appreciated.

[CraigS]

My only experience w/ runflats was when working as a Lexus tech. The sc470 had them and rode like a buckboard. Several owners opted for non RFTs and new wheels. Maybe others will chime in on their experiences.

[Papa]

I have them on my BMW and no spare tire, jack, tools in the car. I don't mind the ride, but I know that a lot of people opt to go to regular tires and toss a spare in the trunk. I'm only concerned with getting a warning that I may have a flat. With regular tires, it's obvious; not the case with RFTs.

Seems like the kit by Schrader is very popular:

https://www.schradersensors.com/en/o...-retrofit-kits

I just don't care for the clunky display.

[David Williamson]

had run flats on a BMW hated them, harsh ride. Check the other Michelin tires, the PSll is an older model since replaced by "SS" now replaced by "S4"
David W

[Avalanche325]

If you are talking about a system that gives you the real readout within 1/2psi, ok. If it is a "tire pressure low" type, I wouldn't bother. For a high performance car, tire pressures should be pretty accurate.

[Derald Rice]

Seems like the kit by Schrader is very popular:

https://www.schradersensors.com/en/o...-retrofit-kits

I just don't care for the clunky display.

Go to some of the RV forums. Some of the systems will link to a cell phone. here is one;
https://www.amazon.com/Bluetooth-Pre.../dp/B073PSD2FL

[Papa]

Go to some of the RV forums. Some of the systems will link to a cell phone. here is one;
https://www.amazon.com/Bluetooth-Pre.../dp/B073PSD2FL

Thanks, Derald! Looks like some interesting options, including one with internal sensors vs. the screw-on caps.

https://www.amazon.com/Bluetooth-Pre...ct_top?ie=UTF8

[BEAR-AvHistory]

My only experience w/ runflats was when working as a Lexus tech. The sc470 had them and rode like a buckboard. Several owners opted for non RFTs and new wheels. Maybe others will chime in on their experiences.

Run with them on my civilian daily driver. First set in 2011 was off in 1500 miles due to ride quality. Next set in 2013 was run till they needed replacement ride was OK but not great. 2014 had a good ride & 2018 had a very normal ride. Replacement tires for both 2014/18 would be current run flats.

[Papa]

Run with them on my civilian daily driver. First set in 2011 was off in 1500 miles due to ride quality. Next set in 2013 was run till they needed replacement ride was OK but not great. 2014 had a good ride & 2018 had a very normal ride. Replacement tires for both 2014/18 would be current run flats.

For my daily driver, I've had Bridgestone Potenzas that were horribly harsh riding, Continental Contact Sports (okay ride), but got talked into Bridgestone Driveguards and they are so much nicer riding plus they can be repaired if they aren't destroyed by driving on them with a puncture and they have a 40,000 mile tread warranty. Unfortunately, options are hard to find for our tire size combination, so it's kinda take what you can get.

[RBachman]

One thought I had on the run-flats with these cars is the weight. Run flats (most anyway) are designed to hold up a car that's heavier than a Cobra. That can contribute to a harsher ride, but are there potential handling and performance differences between the two types that may not be ideal for a Cobra?

[Papa]

It looks like Nitto makes the NT 555 G2 in 315x40-ZR18 as well as the 255x35-ZR18. Now let's see if my Discount Tire can find a set.

[RBachman]

Another thought that may be of some use. I had the externals on my motorcoach. (all 8 tires, and 4 more for the toad...i.e. towed vehicle). It came with a little display that diagramed the coach and car. However, when the tires get changed, I'll install the internals on the coach and leave the externals on the toad. The problem with the external ones is when checking tire pressures, adding or removing air. Mine are anti-theft and there's a special key used to remove and install them. Every time I check tire pressures before a trip they all come off and back on. It's a pain, especially with 12 of the things. There are ones without the anti-theft feature, but they tend to get stolen, and they are not all that cheap.