Wheel & Tire Size

[Worldwide Beagle]

Unfortunately the threshold at which the TPMS light turns on is a lot lower than it should be.

TPMS are only low pressure warning devices, mandated by the govt after the Goodyear or Firestone debacle that killed 12 people. On a god day, They are routinely +-3 psi. Not meant to be accurate gauges. All of mine read 3 psi low. Read the threads on TPMS here. Lots of great info. Please do not use them to set your TP. I think Lucid does a disservice giving us an alleged PSI readout. I prefer the Audi system with just a big red warning and location of funky tire.

 

[HackSaw]

Thanks, hopefully others will check their psi
Climate change will make it worse with Temp fluctuations. I loose 1 a week. if you start at 42, you will be below spec instantly . Low profile tires just do not have the air cushion or sidewall too spare. More really is better!

According to Google:

On average you lose 1 psi in your tires per month

On average, every 10 degrees up/down in ambient temp, you lose/gain 1 psi

After 30 minutes of driving, your tire pressure can go up by ~ 5 psi, due to friction and heat.

Roughly speaking, every 1000ft up in elevation = 0.5 psi up in tire pressure, and obviously vice versa.

 

[HackSaw]

TPMS are only low pressure warning devices, mandated by the govt after the Goodyear or Firestone debacle that killed 12 people. On a god day, They are routinely +-3 psi. Not meant to be accurate gauges. All of mine read 3 psi low. Read the threads on TPMS here. Lots of great info. Please do not use them to set your TP. I think Lucid does a disservice giving us an alleged PSI readout. I prefer the Audi system with just a big red warning and location of funky tire.

The tire pressure on the sensors is required by law to be accurate, what you're probably seeing is the fluctuations due to temperature, elevation, and friction.

 

[P94027]

I attended a Lucid Dream Ahead Tour today in Menlo Park. I was hoping to test a car with the 21-inch wheel and tire combination as I am considering the GT-P or Sapphire. My concern is ride quality as low profile wheel and tire combinations generally are poorer in that regard.

All but one car had 19-inchers. That car had the 20-incher with the Michelin Pilot Sport EV. I drove that for about 45 minutes and thought the ride was more that acceptable. According to the representatives there, if I order a GT-P, I have the option to spec it with the 20’s instead of the 21’s. The Sapphire obviously has no such option (I’ll discuss my conversation about the Sapphire with the reps there and on the phone, in a separate thread).

Interestingly about the 20-inch tire is that the there doesn’t seem to be any range improvement by going from the 21-inch Pirellis to the 20-inch Michelin. They both are listed with a 469 mile EPA range. I wonder if Lucid did not have time to run numbers for the Michelins and opted to be conservative by using the same values from the 21-inch Pirellis. Either that or the Michelins have no efficiency advantage and you only get the better ride qualities offered by their taller sidewalls (and blowout resistance).

Additionally, a cursory web search for the Michelin Pilot Sport EV tire seems to show many complaints about the foam insulation detaching from the tire and causing many issues. Has anyone here experienced that problem?

 

[hydbob]

I attended a Lucid Dream Ahead Tour today in Menlo Park. I was hoping to test a car with the 21-inch wheel and tire combination as I am considering the GT-P or Sapphire. My concern is ride quality as low profile wheel and tire combinations generally are poorer in that regard.

All but one car had 19-inchers. That car had the 20-incher with the Michelin Pilot Sport EV. I drove that for about 45 minutes and thought the ride was more that acceptable. According to the representatives there, if I order a GT-P, I have the option to spec it with the 20’s instead of the 21’s. The Sapphire obviously has no such option (I’ll discuss my conversation about the Sapphire with the reps there and on the phone, in a separate thread).

Interestingly about the 20-inch tire is that the there doesn’t seem to be any range improvement by going from the 21-inch Pirellis to the 20-inch Michelin. They both are listed with a 469 mile EPA range. I wonder if Lucid did not have time to run numbers for the Michelins and opted to be conservative by using the same values from the 21-inch Pirellis. Either that or the Michelins have no efficiency advantage and you only get the better ride qualities offered by their taller sidewalls (and blowout resistance).

Additionally, a cursory web search for the Michelin Pilot Sport EV tire seems to show many complaints about the foam insulation detaching from the tire and causing many issues. Has anyone here experienced that problem?

I think the range being the same has more to do with them both being summer tires than the size difference.

 

[P94027]

Ok, so better stickiness than the 19-inch AS and better ride comfort than the 21-inch. Probably a good middle ground.

 

[Bobby]

Interestingly about the 20-inch tire is that the there doesn’t seem to be any range improvement by going from the 21-inch Pirellis to the 20-inch Michelin. They both are listed with a 469 mile EPA range. I wonder if Lucid did not have time to run numbers for the Michelins and opted to be conservative by using the same values from the 21-inch Pirellis. Either that or the Michelins have no efficiency advantage and you only get the better ride qualities offered by their taller sidewalls (and blowout resistance).

The size of the wheel itself has nothing to do with efficiency. It's the tire compounds and contact patches. The 20 and 21 inch wheels both have summer tires which are more sticky and so they both exert the same range penalty.

 

[stevelitchfieldpark]

Test drive both. I did just that and I decided up on the 21s. I like the handling better and the appearance as well. I am willing to take the mileage penalty.

Agree about the 21's but just changed out the tires for Michelins!

 

[Bobby]

Agree about the 21's but just changed out the tires for Michelins!

I’m waiting for Michelin to release a summer tire in the correct size.