Why 45 psi?

[jmsurpri]

Tire pressure is part of the entire suspension setup. Perhaps it is tuned to provide optimum handling at 45? I find that the ride gets a little bouncy at lower psi.

 

[Deans]

Interesting. I tested it today before I read your post and noticed exactly that. At 35psi I didn't feel any harsh bumps, but some roads gave a bouncy, overly springy feel. This was especially true at higher speeds (45-75mph).
My wife mentioned the same thing without my input.

 

[jerry33]

I was beginning to have excessive center wear at 50 psi. Tesla looked at it and agreed and lowered the pressure back down to 45 psi.

You have to monitor your tire's wear because vehicle placard pressure is just a starting point. Then adjust based on your driving conditions conditions. Just bear in mind that the air pressure is your number one defense against pothole damage.

 

[Barry]

For the record, I usually keep mine in the low 50s. Tire sensors go off at 57, fyi.

Do you sit on a pillow?

 

[jerry33]

Do you sit on a pillow?

I can't tell much difference in the ride. I can tell the difference in tire wear and Wh/mi. Ride comfort is highly subjective.

 

[sorka]

You have to monitor your tire's wear because vehicle placard pressure is just a starting point. Then adjust based on your driving conditions conditions. Just bear in mind that the air pressure is your number one defense against pothole damage.

Huh, I thought the number one defense against pot hole damage was avoiding the potholes

 

[Deans]

Ride comfort is also highly dependent on climate. If you get a lot of freeze/thaw cycles, 50 psi just isn't gonna be fun. I imagine Texas roads are pretty nice. Sporty ride could actually be enjoyable there. Denver has an average high of 46 and an average low of 18 in the winter. Pretty much the worse possible temps for pot hole and crack formations. Add to the fact that Denver doesn't plow it's city streets after snow and the roads just aren't made for sporty suspensions, imo.

Attached is the official load-inflation table, in case anyone wants it.

I'm going to try 35 psi for a few weeks with low passenger loads and see how it goes. If I make a longer trip and/or load up the vehicle with high weight (e.g. family ski trips), I'll bring the pressure back up to 42-45 psi, just to be safe. Most days, I drive under 100 miles so a 10% decrease in range doesn't really matter to me and would only cost me maybe $50/year extra in electricity. Being able to delay neck surgery - priceless.

Totally off topic: getting an EV got us to look at solar. For those of you who haven't looked in to it, I recommend that you do. Prices have come down a lot. If your roof has a clear view of a south facing ski, live in a city that gets a decent amount of sun, plan to live in your home for at least 5 years, and don't own a home that might be bought as a "tear down" in the next 25 years, it's an excellent investment. Better than stocks for sure and with no risk. If nothing else, it's a good way to diversify away from the stock market and get better returns. Take advantage of the Fed tax credits while you can.

 

[jmsurpri]

Interesting. I tested it today before I read your post and noticed exactly that. At 35psi I didn't feel any harsh bumps, but some roads gave a bouncy, overly springy feel. This was especially true at higher speeds (45-75mph).
My wife mentioned the same thing without my input.

I've tried as low as 37ps and as high as 50psi to try to help with rough ride. At 37psi, the car felt too springy/bouncy. It was unsettling and felt like I was in a boat bobbing down the road. At 50psi I couldn't tell much of a difference compared to 45psi. I ended up just leaving it at 45psi, preferring the rough ride over the bouncy ride.

 

[Deans]

I tried it for one day at 35psi. Too springy for me as well. Moved back up to 42psi already. First long trip tomorrow. Will see how it goes.

 

[kort677]

I tried it for one day at 35psi. Too springy for me as well. Moved back up to 42psi already. First long trip tomorrow. Will see how it goes.

IMHO in your part of the world 42 is too low of a PSI

 

[Wuggado?]

Yours are a "thinner" lower profile tire so basically less air is required. No, the sticker is for your own rim/tire setup. Periodically I switch the right scroll wheel to display "Car Status" which is the PSI pressure of all four of the tires. When they lose a pound or so I use a nice digital pressure guage that I found on Amazon.com and this to fine tune it.
Tesla — Tire Repair Kit

Interesting. Parked in the garage my right scroll wheel does not display 'Status' as an option. Any idea why that would be?

 

[Deans]

If you scroll, you should see a wheel icon. I think it says "car". Press it and it should show a picture of your car with PSI for each tire and show any doors that are open, etc.

 

[msnow]

Interesting. Parked in the garage my right scroll wheel does not display 'Status' as an option. Any idea why that would be?

Press down, hold and scroll to change to that display option.

 

[kort677]

Interesting. Parked in the garage my right scroll wheel does not display 'Status' as an option. Any idea why that would be?

you need to scroll to the little picture of the tire to bring that info up

 

[Wuggado?]

Press down, hold and scroll to change to that display option.

Got it, thanks. The display doesn't fill in any values for tire pressure. Maybe it takes a bit.

 

[FlatSix911]

All tire pressure recommendations are based on a set of assumptions. The basic four are:
1. The ambient temperature is 18C (65F). If it's higher than that you need to adjust the pressure upwards.
2. Speed. The GY chart (and all other charts from the tire manufacturers (as far as I know) are based on a 65 mph sustained speed. If you run faster than that, then you need to up the pressures.
3. Load. For cars the load that the pressure recommendations are set at are for what the engineer thinks is going to be normal for that car--not necessarily the GVW.
4. A daily pressure check at the start of each driving day. (Don't shoot the messenger.) If you don't check every day, then you need to adjust the pressures upwards so that you never go below. Note that track use--where you adjust the pressures to get the most contact area is a whole 'nuther subject, and basically not applicable to normal driving (unless you like buying tires frequently).

Good post ... here is another guide for those who spend a fair bit of time at the track... Not for Road Use

 

[FlatSix911]

For what it's worth, the door jamb placard on my March 2015 build Model S with 19" Michelins calls for 50 psi.
It looks like Tesla recommended 50 for a while, then went back to 45 psi.

When Tesla did the annual service on my car, they went to the trouble to reduce my tire pressure from 50 to 45.
I will set them back to 50.

GSP

Correct ... here are the current tire pressures recommended by Tesla

 

[tomas]

the door sticker is misinformation? could it be the russians hacking?

Not funny. That's not what jerry said. Misinformation is the 34-35 BS out there and the discount tire idiots, not the door stickers.

 

[Redmiata98]

Wuggado, from page 150 of the Owner's Guide:
"After inflating the tire to the recommended pressure, you must drive over 25 mph (40 km/h) for more than 10 minutes to activate the Tire Pressure Monitoring System (TPMS)."

 

[roblab]

Got it, thanks. The display doesn't fill in any values for tire pressure. Maybe it takes a bit.

I had heard that the pressure sensors had to pass by a receiver. When the car isn't moving, it doesn't read.