Model 3 Tire Pressure

[Feathermerchan]

I drain and fill my tires regularly. At least twice a year.

 

[MentalNomad]

I personally think it's more important to always have tires filled properly, and to really do that you need to fill with air, not nitrogen, so that you can always top off whenever needed.

Well, since I don't mind topping off with a little air if I need a pound or two (which is mostly nitrogen anyway, as you say), then I suppose it's fine.

Though, in reality, I've never had to in the past 5 years or so.

I always find it convenient and free to top off with nitrogen, so I'll just keep doing that, despite your insistence that I can only do it with air.

 

[SomeJoe7777]

I always find it convenient and free to top off with nitrogen, so I'll just keep doing that, despite your insistence that I can only do it with air.

It's awesome if that's available to you, but around here where I live it's not, as far as I know. Only major tire shops have nitrogen available, and they typically charge at least a few dollars per tire to fill. If I'm on a road trip or something, it would be very difficult for me to find nitrogen if I needed it.

 

[bradhs]

P3D+ 20" stock performance rims
Micheline Pilot Sport 4S
245/35 ZR 20
These are 10mm wider that stock.

38 PSI

 

[rlb4]

If it's free, that's much better and may be worth it, but then the situation arises thus:

- You fill the tires with (free) nitrogen.
- The temperatures drop, along with that the pressure in the tires.
- You want to bring the pressures back up for efficiency, ride, and handling characteristics.
- You now have to find a nitrogen source, which may not be readily available.

Nitrogen filled-tires can kind of lock you into the dilemma of 1) do I fill the tires now with air, contaminating the nitrogen fill, requiring drain and re-fill later, or 2) wait and fill with nitrogen later, but drive until then on under-inflated tires.

I personally think it's more important to always have tires filled properly, and to really do that you need to fill with air, not nitrogen, so that you can always top off whenever needed.

Why can't you add air to nitrogen filled tires?

 

[SomeJoe7777]

Why can't you add air to nitrogen filled tires?

You can of course, nothing bad will happen. But you kind of defeat the purpose of the nitrogen fill.

1. Nitrogen is guaranteed to be dry (no water vapor), and if you top off with air, that's not guaranteed to be dry. (It can be depending on the drying equipment in the air compressor system, but that varies).

2. One of the purposes of nitrogen is to eliminate oxygen from the inside of the tire, this supposedly reduces corrosion potential and rubber degredation. By topping off with air, you introduce oxygen into the tire.

If you paid for the nitrogen fill in the first place, introducing air means you'll have to have the tire drained of the mixed gas and refilled with nitrogen in order to restore the nitrogen benefits. In many cases, this incurrs a cost that you otherwise would not have had to pay if air was not used for the top-off.

 

[rlb4]

You can of course, nothing bad will happen. But you kind of defeat the purpose of the nitrogen fill.

1. Nitrogen is guaranteed to be dry (no water vapor), and if you top off with air, that's not guaranteed to be dry. (It can be depending on the drying equipment in the air compressor system, but that varies).

2. One of the purposes of nitrogen is to eliminate oxygen from the inside of the tire, this supposedly reduces corrosion potential and rubber degredation. By topping off with air, you introduce oxygen into the tire.

If you paid for the nitrogen fill in the first place, introducing air means you'll have to have the tire drained of the mixed gas and refilled with nitrogen in order to restore the nitrogen benefits. In many cases, this incurrs a cost that you otherwise would not have had to pay if air was not used for the top-off.

Thanks. I wasn't sure if there was a reason you shouldn't add air to nitrogen. So it's ok if one gets nitrogen for free and needs to add air for some reason.

 

[mswlogo]

You can of course, nothing bad will happen. But you kind of defeat the purpose of the nitrogen fill.

1. Nitrogen is guaranteed to be dry (no water vapor), and if you top off with air, that's not guaranteed to be dry. (It can be depending on the drying equipment in the air compressor system, but that varies).

2. One of the purposes of nitrogen is to eliminate oxygen from the inside of the tire, this supposedly reduces corrosion potential and rubber degredation. By topping off with air, you introduce oxygen into the tire.

If you paid for the nitrogen fill in the first place, introducing air means you'll have to have the tire drained of the mixed gas and refilled with nitrogen in order to restore the nitrogen benefits. In many cases, this incurrs a cost that you otherwise would not have had to pay if air was not used for the top-off.

Not saying anything against Nitrogen but...

I’ve run winter tires for 12 seasons (I know your not supposed run any tire beyond 7 but the tires were perfectly fine). But they were getting tired by the 12th year. Still had good tread. Nokian’s. Car had 230k miles. Never had mag wheels corrode inside with air. Plenty of pits on the outside though.

 

[Randy Spencer]

Hmmm.. So I just had my snow tires mounted, and despite being placed in tire covers, they were outside and at least one of them had water sloshing around in them. I didn't see the guys at the shop pull out towels. Would they have just LEFT the water inside? Other than in freezing conditions does it matter? Not sure I even saw them balance them.

I guess I could park on a slope and with the air nozzle pointed down I could let some air out and see if water comes out too.

 

[Bubbatech]

Nitrogen in the tires is a real bonanza for dealers. The dealer buys a regulator for about $110 (one time only) and a tank is a few dollars a month. The profit margin is immense. While there might be theoretical benefit to eliminating the oxygen and some water vapor from the interior of the tire, on the relevant time scale of an average driver (a few years), i have a hard time believing that the use of pure nitrogen will make any discernible difference. The exterior of the tire is subject to much harsher conditions than the interior will ever see and the interior components of the wheel are designed to withstand the relatively mild environment of the tire interior. If oxygen or moisture played a significant role in tire deterioration on a time scale of years, we would observe degradation on the outside of the tire that would require premature tire replacement. We don't. In fact, the limiting factor for those who use their cars is tread wear and physical damage from objects and driver error. Therefore, IMHO it is not beneficial to use nitrogen in tires.

 

[Electric Dream]

For those of you who are asked if you want N2 in your tyres, ask the fitter:
1. Is their N2 completely dry?
2. How will they purge all the existng air out of the tyres after mounting them?

 

[MentalNomad]

It's awesome if that's available to you, but around here where I live it's not, as far as I know. Only major tire shops have nitrogen available, and they typically charge at least a few dollars per tire to fill. If I'm on a road trip or something, it would be very difficult for me to find nitrogen if I needed it.

I guess I'm just lucky to live in an area near a Costco. They do free nitrogen, and you can top up any time.

 

[Feathermerchan]

2. How will they purge all the existng air out of the tyres after mounting them?

There's a drain in the bottom of the tire (tyre) to let the air out.

 

[Trebor Srevlis]

Note that door stickers are tire pressure for max gross weight, so a fully loaded car with luggage and ~800lb of passengers. So perhaps 40 is best for normal use.

 

[Tha_Reaper]

I'm driving around with 46-47 psi. The ride is smooth enough for the type of roads that I take, the wear on the tires are even showing signs of under-inflation. The energy consumption is pretty low, so I'm happy with this overall

 

[Bubbatech]

I'm driving around with 46-47 psi. The ride is smooth enough for the type of roads that I take, the wear on the tires are even showing signs of under-inflation. The energy consumption is pretty low, so I'm happy with this overall

My car was delivered with the tires at 47 psi.

 

[mswlogo]

My car was delivered with the tires at 47 psi.

What a car is delivered with for tire pressure is totally meaningless.
Did you keep the seat and mirror positions too?

 

[Bubbatech]

What a car is delivered with for tire pressure is totally meaningless.
Did you keep the seat and mirror positions too?

There is no quantitative specification for mirrors and seats. There are engineering specifications for tires including pressure. Any dealer or delivery organization worth its salt will inflate tires to spec at the time of delivery. That is also specified on the door decal and on the tire sidewall. A car dealer or manufacturer will inflate tires to plus or minus 10% of the engineering spec.

 

[mswlogo]

A car dealer or manufacturer will inflate tires to plus or minus 10% of the engineering spec.

Plus or minus 10%, that's exactly why what it's delivered with is totally meaningless. I've also seen way worse than 10%.

What the manufacturer puts in (for shipping) is also irrelevant, typically very high.

Owners can adjust to their personal taste (as this very topic is discussing), just like the mirrors and seats. Within reason of course.

Again, what it's delivered with means absolutely nothing.

Personally Model 3 felt like riding on basket balls even at 45 psi (cold), never mind 47 psi (cold).
My AWD (Stealth) Model 3 with 18" door tag showed 42 lbs (which is what I ran and was plenty).

 

[Knightshade]

FWIW, the CEO of Tesla says 39 psi for best ride

Elon Musk on Twitter