Why 42 PSI ?

[Willy’sEV]

Think the pressure is a factor into efficiency which along with Lucid and now Hyundai/ioniq6 lead rhe industry
What’s Lucid guidance with psi on their vehicles?

Go to the Lucid website, this is a Tesla website

 

[kpanda17]

Lucids tire pressures from their owners manual
These high pressures are def an EV performance and efficiency need

 

[3sr+buyer]

Lucids tire pressures from their owners manual
These high pressures are def an EV performance and efficiency need
View attachment 952982

In contrast, the Hyundai Ioniq5 and Kia EV6 tire pressure recommendations seem to be 34-38psi, depending on 2WD/AWD and wheel/tire size.

The Chevrolet Bolt tire pressure recommendation is 38psi.

 

[kpanda17]

Agree, not clear cut

 

[SalisburySam]

And my 2018 Model 3 LR RWD specifies 45psi all around. Later models lowered this to 42psi.

 

[beachsideev]

I could have sworn my 20 m3 said 45. Also the sc always set it to 45 when they rotated the tires.

That explains why the tires on my new m3 were about 42 when I checked them this weekend before a road trip. I guess they didn't need about 3 psi each.

 

[GSP]

Interesting about the cold weather making the liner stiff. I got the car a couple months ago so I haven't had a chance to see what it's like in warm weather, but I'll be looking out for that. And yes, the MXM4 do not feel impressive in any conditions, they seem completely focused on efficiency. I am also a Michelin fan, usually Premier A/S on the family car and Pilot Sports on my fun cars.

Funny you mention that you did an early replacement of the MXM4s with CrossClimate2s - I was just on TireRack doing some research with the same idea in mind! The CrossClimates get incredible reviews everywhere you look; they seem to be the new all season king. However, this (incredibly relevant) TireRack test did put a damper on that idea a little bit - they used a Model 3 to compare the OEM Tesla MXM4 vs the CrossClimate2 and found that the CrossClimate2 is a better tire in almost every way, but that you pay for that in a significant range hit.

https://www.tirerack.com/tires/tests/testDisplay.jsp?ttid=298

It made me a little hesitant about ditching the MXM4s since I was hoping to do some road trips this summer. It'd be a bummer to lose 10% of my range just to tires. Have you had the CrossClimates on a road trip?

I put CrossClimate2s on my Model 3 LR RWD a couple of years ago. I didn't keep track of my Wh/mi consumption before and after, but it seems like it went up after replacing the OEM Michelins.

I have not noticed any difference when making long road trips. I like to drive 400 mi/day on these trips, but sometimes go over 600 mi/day. I stop at a supercharger every 2 hours or so for a restroom or meal break. The car is always sufficiently charged before I am done with my break. The car still has more than enough range, and its high charging speed makes road trips easy.

The increased traction, especially on snow or ice, gives me year-round confidence, and it is well worth the range hit IMO.

GSP

PS. Back to the topic: My preference is to run as high a pressure as possible without undue tradeoffs. So a bit different from most posters in this thread. I use the door placard pressures as my lowest setting, and the tire sidewall max pressure as my max. I ran my Chevy Volt tires at 50 psi. Tesla recommended 50 psi for my 2015 Model S, as my door placard said, but later changed their recommendation to 45 psi. I ran them at 50. I have run my Model 3 at 50, but lately have reduced to Tesla's recommended 45 psi. My Model Y has a door placard recommendation of 42 psi, and I pretty much stick to that.

 

[SalisburySam]

I ran my Chevy Volt tires at 50 psi. …50 psi for my 2015 Model S…have run my Model 3 at 50

Running at higher-than-recommended or tire max pressures…any untoward center tread wear as a result?

 

[rpiotro]

Think the pressure is a factor into efficiency which along with Lucid and now Hyundai/ioniq6 lead rhe industry
What’s Lucid guidance with psi on their vehicles?

Lead the industry? Neither of those cars come close to the MPGE of my 2021 SR+.

 

[kpanda17]

Lead in vehicle efficiency, eMPG

 

[rpiotro]

Lead in vehicle efficiency, eMPG

eMPG? In the U.S. I'm pretty sure it is expressed as MPGe. Where are you from? Have you actually looked at those values for the vehicles cited?

 

[kpanda17]

my bad MPGe
Im front earth.
Yes, they lead the industry

 

[Kevy Baby]

I put CrossClimate2s on my Model 3 LR RWD a couple of years ago. I didn't keep track of my Wh/mi consumption before and after, but it seems like it went up after replacing the OEM Michelins.

I took a definite consumption hit when I switched to the CC2s - about 10-15 Wh/mi. This hit has been widely reported here in multiple threads. Seems like the original MXM4s get the best mileage (based on my arbitrary and unreliable memory).

 

[Gasaraki]

Not true. Max pressure is max COLD pressure.

And how is what you said different than what he said?

I kept my tires at 42……and I was blessed with replacement at 22K miles.
Shortest life on tires ever for me.

I don't see how those two are related.

 

[texas_star_TM3]

for comfort i wouldn't go above 40 psi... 39-40psi seems to be the sweet spot for me. 42/43 psi for best range

 

[GSP]

Running at higher-than-recommended or tire max pressures…any untoward center tread wear as a result?

None. I read websites promoting higher pressures for efficiency, and they claimed that modern tries don’t wear in the center like old bias ply tires do. Even at pressures somewhat above the max pressure on the tire sidewall.

I figured why not try it on a set of tires and see for myself? I now have worn out several sets of Michelins running at 50 psi, and they all had even tread wear from side to side.

GSP

 

[alhounos]

my bad MPGe
Im front earth.
Yes, they lead the industry

Lucid recommends 49psi for 19”s, so I would say it’s fair to assume that the higher pressures you’re running the better your efficiency, within reason.

Of course the lucid has air suspension to make up for those rock hard tires. I will continue running 40 for comfort.

 

[DrChaos]

I don’t understand the question?

Every car manufacturer has various tire suppliers and recommends the same pressures for the same tire size. It’s mostly a factor of desired rolling resistance and rolling diameter and suspension tuning. But even then a couple PSI is not likely to make a noticeable difference.

Agree.

PSI * contact_patch_area * 4 = weight of vehicle

Sir Isaac Newton demands it.

 

[rjpjnk]

That actually makes a lot of sense now that you mention it. So since the weight of the car is constant, the contact area is inversely proportional to pressure. But what about the pressure due to the elasticity of the tire itself? We can inflate a tire to 40 psi even with no weight on it.

 

[DrChaos]

That actually makes a lot of sense now that you mention it. So since the weight of the car is constant, the contact area is inversely proportional to pressure. But what about the pressure due to the elasticity of the tire itself? We can inflate a tire to 40 psi even with no weight on it.

The pressure being measured inside the tire includes compressibility of air and the change in volume from elasticity of the tire and the PSI is measured and set with the car's weight and the tire stretching.