PSA: your tire pressure may be too high.

[GarrickS]

Hi all, the tire pressure in my new Model 3 was too high. It was delivered with 47-50lbs. The result is a bouncy ride. I let out some air.... 43lb in front and 44lb in the rear. The ride is much much better.

So you might want to check your tire pressure!

 

[Boourns]

What does the label on the door sill say?

 

[shokunin]

The door sill sticker with 18's say 45psi front and rear. Just checked the tires and all were high by 1-2 psi, back off some air, but it wasn't alot.

 

[insaneoctane]

Does the TPMS display pressures? Are they accurate enough for this exercise?

 

[Stoneymonster]

Does the TPMS display pressures? Are they accurate enough for this exercise?

Yes to the first, probably maybe to the second?

 

[GarrickS]

Does the TPMS display pressures? Are they accurate enough for this exercise?

Yes, and they exactly matched my analog guage.

 

[David29]

I hope everyone is checking them cold, not warm from driving.

 

[North75]

45 PSI seems high. From what I recall, all of my other cars are in the low to mid 30's.
Do other Tesla's have high recommended pressures? Is it a characteristic of low rolling resistance tires?
I'm just curious.

 

[dhanson865]

I hope everyone is checking them cold, not warm from driving.

I second that, 45 PSI cold in the coldest part of the day in the shade when the car hasn't been driving for several hours.

Sunlight, friction, any heat source and you'll end up with either uneven tire pressure between sides or front/back and you'll end up with at least some of the tires under inflated.

 

[dhanson865]

45 PSI seems high. From what I recall, all of my other cars are in the low to mid 30's.
Do other Tesla's have high recommended pressures? Is it a characteristic of low rolling resistance tires?
I'm just curious.

Some Tesla's run at 51 psi. Modern cars are moving to higher and higher tire pressures over time.

Most Teslas do NOT have low rolling resistance tires.

Tire pressure is unrelated to the style of tire, its a function of the cars weight/size/suspension design.

EVs do tend to be heavier and you have to have higher PSI to get the max load rating on most tires.

 

[Sawyer8888]

Tire pressure will increase as the tires warm up and vice versa.

My guess is the door sticker provides max pressure stats for when the vehicle is at rest (cool tires). So if you are monitoring the tire pressure while driving or just after you've reached your destination, the pressure will be a bit higher. If slightly over the recommended pressure (5 lbs or so), I wouldn't touch them.

 

[GarrickS]

If you feel like you are driving on basketballs, bleed out a few pounds. Don't overcomplicate it

 

[dgpcolorado]

45 PSI seems high. From what I recall, all of my other cars are in the low to mid 30's.
Do other Tesla's have high recommended pressures? Is it a characteristic of low rolling resistance tires?
I'm just curious.

Mid 40s is typical for Tesla. It might be because the cars are quite heavy and LRR tires have more flexible sidewalls. My door placard is 42 but I get fairly even tire wear at 45-46 plus better efficiency.

 

[TexasEV]

45 PSI seems high. From what I recall, all of my other cars are in the low to mid 30's.
Do other Tesla's have high recommended pressures? Is it a characteristic of low rolling resistance tires?
I'm just curious.

Tesla is not your other cars. My Model S 60 from 2013 has recommended 45 PSI with the Michelin Primacy tires or 42 PSI with the Goodyear Eagles.

 

[Kenriko]

45 PSI seems high. From what I recall, all of my other cars are in the low to mid 30's.
Do other Tesla's have high recommended pressures? Is it a characteristic of low rolling resistance tires?
I'm just curious.

Pretty normal to have higher PSI for low profile tires.

 

[dhanson865]

Tire pressure will increase as the tires warm up and vice versa.

My guess is the door sticker provides max pressure stats for when the vehicle is at rest (cool tires). So if you are monitoring the tire pressure while driving or just after you've reached your destination, the pressure will be a bit higher. If slightly over the recommended pressure (5 lbs or so), I wouldn't touch them.

Close, the corrected statement is:

The door sticker provides recommended pressure for when the vehicle is at rest (cold tires).

The maximum pressure is on the side of the tire. You are free to use any pressure between the recommended and maximum.

Also if the tire pressure hot goes above the maximum pressure on the tire that is OK. The maximum pressure on the tire is for when the vehicle is at rest (cold tires).

So for example if the label on the door jamb says 45, and the tire says 51, it's OK if they are 50 cold and 55 hot. It's also OK if they are 45 cold and 50 hot. Anywhere in between is good, 45 cold, 46 cold, 47 cold, 48 cold, 49 cold, 50 cold all work.

What's bad is if they are 40 cold and 45 hot. At that point you are responsible if a tire fails as you didn't keep the pressure high enough for the vehicle it's on. Odds are being low isn't going to do more than waste energy, but if you drive very fast for a long time the tire can overheat if it is under inflated.

Under-inflation is one of the leading causes of tire failure. If tire pressure is too low, too much of the tire's surface area touches the road, which increases friction. Increased friction can cause the tires to overheat, which can lead to premature wear, tread separation and blowouts

 

[SageBrush]

The door sticker provides recommended pressure for when the vehicle is at rest (cold tires).

Yep, but I've never understood how the door sticker knows which tyres are on the car. Even the car OEM uses different sizes and brands

 

[dhanson865]

Yep, but I've never understood how the door sticker knows which tyres are on the car. Even the car OEM uses different sizes and brands

The sticker doesn't know. The recommendation is for the vehicle. The sticker tells you what the tires have to be able to handle.

The responsibility is that you must find tires that fit and are the right size (more than just fit on the wheel and fit in the wheel well, they need to have the right diameter and revs per mile to keep the speedometer within accuracy limits and not get RPMs too high or too low for the gearing) and have a max tire pressure equal to or greater than the door sticker.

If the door says 45 and the side of the tire says 44 then your tires officially aren't fit to be put on that vehicle and you would be liable for any damages, wreck, tickets by police, and such for running substandard equipment.

Just make darn sure your tires have a number for max PSI equal to or greater than what your car needs.

 

[DR61]

Yep, but I've never understood how the door sticker knows which tyres are on the car. Even the car OEM uses different sizes and brands

The door placard pressure is based on the size and load rating of the tires (which should also be there), and not the brand. It is the minimum pressure to handle high speeds with maximum load (plus a safety factor) for any brand with appropriate size/load rating.

Note if you set your pressures when it is 60 deg F 'cold' in your garage, and then you park outside all day at 15F, your tire pressures will drop significantly.

 

[SageBrush]

The sticker doesn't know. The recommendation is for the vehicle. The sticker tells you what the tires have to be able to handle.

The responsibility is that you must find tires that fit and are the right size (more than just fit on the wheel and fit in the wheel well, they need to have the right diameter and revs per mile to keep the speedometer within accuracy limits and not get RPMs too high or too low for the gearing) and have a max tire pressure equal to or greater than the door sticker.

If the door says 45 and the side of the tire says 44 then your tires officially aren't fit to be put on that vehicle and you would be liable for any damages, wreck, tickets by police, and such for running substandard equipment.

Just make darn sure your tires have a number for max PSI equal to or greater than what your car needs.

Thanks, but that is still a partial explanation ... I think. Consider:

A sticker that says 35 psi.
One tyre that rates maximum PSI at 35 psi;
And another that rates maximum PSI at 51 psi.

Will performance on this car be the same regardless of tyre choice when inflated to 35 psi ?