Tire Pressure and tire life expectancy

[Sparrow]

I was curious given the apparent fact that the Roadster tires wear out quickly, are there many people over inflating their tires to hopefully extend the life of their tires while also improving their driving range. Since most tire wear I have seen on other cars has been on the edges of the tire, maybe having a higher pressure in the tire will allow more even wear in the center too.

[Lancelac]

I slightly overinflate, and had no problem with uneven wear. Stil, I am about to replace my summer tires (about 5000 miles on them), the rear because they are bald, the fronts because driving around in the city (and having such soft tires) has rewarded me with a bolt stuck into both of them. The bolts were in there for months without even slow loss of air pressure, but in the long term it'll cause a blowout, so I'm replacing them all.

[Talkredius]

assuming your tire pressure is in the spec range, the live time depends only on the way you drive and the rubber mixture of the tires. Heavy acceleration combined with twisty roads means max.fun but min. life time.
low acceleration combined with straight highways means max. life time.
If you over inflate your tires a little bit (as I do too) you'll get a lower roll resistance but you may loose some marginal grip. If you extremely over inflate your tires they are not flat any more but more like balls.
This means lower roll resistance but also substantial loss of grip. And of course they will wear out more quickly, because they are only rolling on the edge of the "ball" in the middle of the tire.

For drag races on (secured) tracks you reduce you pressure a lot, not for the grip but to get the tires more quickly to the right temperature and then get the max grip.
Expect a life time of a week end or so.

Never do this on normal roads, it is deadly dangerous.

If the tires are worn out at the edges of the tire, left or right side of the tire, then something is wrong with alignment or camber.

[Sparrow]

I got my 2008 Roadster used with 5500 miles on it and I have put an additional 1500 miles on it in the 2 months I have had it. The tires do not look worn to me at this time and I would like to maximize their remaining life. Having been the owner of some very underpowered EVs, the Solectria Force (0-60 in about 20 seconds), I have no trouble driving the Roadster sedately most of the time so I am already doing that to maximize my tire life.

When I got the car, the tires were 36 front and 46 back, is that slightly overinflated or way overinflated? What are you running them at?

[Talkredius]

I always running my cars with max. pressure (spec) + 0.3 bar (+4,35 psi)
The Roadster with 2.4 bar (34,8 psi) front and 3.1 bar (44,96 psi) rear.
I would feel safe with 36 / 46.
I guess the "ball effect" starts above 4 bar (58 psi), I'll ask my brother, owner of a tire shop, tomorrow (European time ) for more accurate datas

[n8te]

I would adjust understeer tendency with adjusting the anti-roll bars and the camber, not the tire pressure.

[Alan]

As above, if you have adjustable suspension then adjusting the shocks and anti roll bars (covered in other threads) is the way to go.

Just adjusting tire pressures will help though. To reduce the bumpy ride, you need lower tire pressures but to reduce understeer you need to increase the front tire pressure so to an extent you can not have both grip and comfort.

Reducing rear tire pressure will be a win/win for you as it will lower understeer and improve the bumpy ride. I assume the lowest rear pressure you can have without the tire pressure monitoring getting upset is going to be 36psi (as above) so try that with say 30 at the front.

You can drop the front pressure a bit more for a softer ride (and perhaps a better feel through the steering) but this reduces front end grip a bit so understeer will increase.

Having owned several Lotus over the years, I have always found that the suspension settings / tire pressures are very sensitive to changes and it seems the same on the Tesla. A few psi change in tire pressure can make a big difference to how the car feels.

[AndrewBissell]

A Tesla service person confirmed that 35 front 45 rear is safe and will extend range.

[Talkredius]

here as promised the more accurate datas :

a) min pressure

min. pressure (spec) - 0.5 bar (7.25 psi) is dangerous, you should never drive with such a low pressure. If the pressure drops to this point e.g because you got a bolt in your tire you may drive very carefully with low speed to the next garage nearby.
For a longer distance you should stop the car and fix it. (Use the tire sealant kit or get a new tire or transport the car with a truck). Keep in mind, new rims are quite expensive, I know what I'm talking about

b) max pressure

The max. pressure is printed on your tire. That may differ from the recommended max. pressure in the manual. For my rear Hancock winter tires I found 3.4 bar (50 psi) as the max. pressure on the tire (see the attached picture)


You may use a 20 % higher pressure as it is labeled on your tire but that is not recommended. If I would get into an accident not caused by me, in Germany the insurance company might pin some guilt on me, because the tire pressure was out of the tire specs. (If they can proof it)


And, as Alan already mentioned, any significant change to the tire pressure may result in a different handling of the car. If you make some changes to the pressure, drive carefully the first few miles , don't start like a rocket

[Sparrow]

Thanks for the input. I've found out that the car's tire sensors don't like pressures above 50psi for the rear tires. I'm guessing the front tires would be 40 psi maximum before the sensors give the warning.