Cars with multiple tire pressures listed.....

[OVERKILL]

So I'm trying to figure out what pressure to run in the M5 for the winter. And before somebody has a smart comment about checking the placard, the placard lists three different pressure settings for the car:

1. USA: 40/44
2. Europe: up to 4x passengers: 34/38
3. Europe: fully loaded to capacity: 44/48 (IIRC)

I'm currently running #2, as that's what I ran in my summer tires. The tire shop had set the fronts to 38, the rears to 36..... LOL

I'm just not sure on what pressure would yield the best winter traction

 

[MarkStock]

According to Firestone, it should be 39 / 46.

Tirerack has some useful articles on the topic. Doing what the manufacturer says is very important for excavating the maximum amount of water.

 

[default]

I usually run the lowest recommended in winter, I figure this helps keep the tire warmer and increases my contact patch.

What was really interesting was the inflation specs for my 1992 Camry, It said to inflate the tires to sidewall(44psi) if driving over 100 mph for extended periods. A stupid 16 year old me checked on a very empty road, I don't think maintaining 100 was feasible with that 4 banger and its automatic trans, seemed to stop pulling at around 90. I ran em at 44 anyways because it handled better and felt less like a OPC.

 

[BMWTurboDzl]

I've always read Mike Miller opine that US psi is unnecessarily high ever since the Ford/Firestone fiasco. Good luck with this. Perhaps download a manual from BMWNA/CA website?

 

[Donald]

Some have different pressures per engine. In my case the Cummins diesel weighs 1000 lbs and they have a higher tire pressure in the front than the rear.

 

[OVERKILL]

Originally Posted By: MarkStock
According to Firestone, it should be 39 / 46.

Tirerack has some useful articles on the topic. Doing what the manufacturer says is very important for excavating the maximum amount of water.


I am doing what the manufacturer says. Unfortunately the manufacturer doesn't give a single option, but rather THREE.

 

[eljefino]

What are your temp swings like?

I tend to go from -10'F to +30 over and over. I don't want to mess with my tires at -10 so I set them at sidewall pressure at +30 and they naturally fall to placard pressure when it's wicked cold.

 

[SwampSurvivor]

I always run the max on the sidewall

 

[bar1]

Nokian, Continental, etc, all recommend using fully loaded capacity (#3) for winter tires. They also state that you can go 10% up from fully loaded capacity.
I use #3 on my winter tires, studded or not..

 

[OVERKILL]

Originally Posted By: Miller88
I always run the max on the sidewall


Why the heck would you do that? That's the maximum for the TIRE, not the recommended pressure set by the manufacturer of the VEHICLE.

Two very different things......

 

[OVERKILL]

Originally Posted By: bar1
Nokian, Continental, etc, all recommend using fully loaded capacity (#3) for winter tires. They also state that you can go 10% up from fully loaded capacity.
I use #3 on my winter tires, studded or not..


Interesting, I'll see if Bridgestone says the same, thanks for that

 

[OVERKILL]

Originally Posted By: eljefino
What are your temp swings like?

I tend to go from -10'F to +30 over and over. I don't want to mess with my tires at -10 so I set them at sidewall pressure at +30 and they naturally fall to placard pressure when it's wicked cold.


It tends to get cold, and then stay relatively cold. Right now we have swings, but that'll get less frequent as winter sets in.

 

[OVERKILL]

Originally Posted By: MarkStock
According to Firestone, it should be 39 / 46.

Tirerack has some useful articles on the topic. Doing what the manufacturer says is very important for excavating the maximum amount of water.


Yup, just got that information myself from their website.

Looks like 39/46 it is.

Thanks again for all your help guys!!!

 

[bar1]

Originally Posted By: OVERK1LL

Interesting, I'll see if Bridgestone says the same, thanks for that

Don't know Bridgestone's recommendation or Nokian/Continental international.
The Norwegian divisions/branch of Nokian/Continental recommends #3, and when car is fully loaded, #3 +10%.
Some areas here has 6 months (or more) of winter... (average day temperature below 0C).

 

[MarkStock]

Originally Posted By: OVERK1LL
Originally Posted By: MarkStock
According to Firestone, it should be 39 / 46.

Tirerack has some useful articles on the topic. Doing what the manufacturer says is very important for excavating the maximum amount of water.


I am doing what the manufacturer says. Unfortunately the manufacturer doesn't give a single option, but rather THREE.


Originally Posted By: OVERK1LL
And before somebody has a smart comment about checking the placard, the placard lists three different pressure settings for the car:

1. USA: 40/44
2. Europe: up to 4x passengers: 34/38
3. Europe: fully loaded to capacity: 44/48 (IIRC)

I'm currently running #2, as that's what I ran in my summer tires.


Does the placard really give you 3 options?

Option 1 is for the USA. I presume you are in the USA with a US spec car?

Options 2&3 are for Europe.

I don't know why you went for the Europe spec in the first place.

Also, if BMW felt that there was a different spec for summer vs wwinter pressure, I think they would have given it, especially for Germany where winter tires are mandatory.

The tire rack info I refered to spoke about the manufacturer specified tire pressure as being the one that made the biggest and most even tire footprint possible. This is what gives the best grip and water evacuating properties. I doubt whether this would change between summer and winter tires.

 

[OVERKILL]

Originally Posted By: MarkStock
Originally Posted By: OVERK1LL
Originally Posted By: MarkStock
According to Firestone, it should be 39 / 46.

Tirerack has some useful articles on the topic. Doing what the manufacturer says is very important for excavating the maximum amount of water.


I am doing what the manufacturer says. Unfortunately the manufacturer doesn't give a single option, but rather THREE.


Originally Posted By: OVERK1LL
And before somebody has a smart comment about checking the placard, the placard lists three different pressure settings for the car:

1. USA: 40/44
2. Europe: up to 4x passengers: 34/38
3. Europe: fully loaded to capacity: 44/48 (IIRC)

I'm currently running #2, as that's what I ran in my summer tires.


Does the placard really give you 3 options?

Option 1 is for the USA. I presume you are in the USA with a US spec car?

Options 2&3 are for Europe.

I don't know why you went for the Europe spec in the first place.

Also, if BMW felt that there was a different spec for summer vs wwinter pressure, I think they would have given it, especially for Germany where winter tires are mandatory.

The tire rack info I refered to spoke about the manufacturer specified tire pressure as being the one that made the biggest and most even tire footprint possible. This is what gives the best grip and water evacuating properties. I doubt whether this would change between summer and winter tires.


No, I'm in Canada, with a Canada-spec car. Unfortunately there isn't a "Canada specific" section on the placard. So that really leaves all three options on the card open to me....

What I find curious is why Europeans are given the option of running two different pressures based on how the tires are used, whilst the USA audience is given a single recommendation that sits half way (roughly) between the two Euro options....

 

[bar1]

Originally Posted By: MarkStock

...I think they would have given it, especially for Germany where winter tires are mandatory...


Germany...winter? Are you kidding...

If your talking Europe, look at what is recommended in Scandinavia or Russia, areas/countries that has real winter conditions.

 

[JHZR2]

US value looks like a good compromise. I like to run a little harder for economy and life.

 

[Garak]

Originally Posted By: OVERK1LL
What I find curious is why Europeans are given the option of running two different pressures based on how the tires are used, whilst the USA audience is given a single recommendation that sits half way (roughly) between the two Euro options....


That is odd. Any other Euro car drivers here see such a thing? My Audi didn't have that, but it was rather old.

Maybe the U.S. has one tire pressure listed the same way as all of North America is supposed to use one viscosity of oil.

Really, though, does yours have a TPMS? If that's standard in North American cars but perhaps not European cars, they might calibrate the TPMS for a middle of the road kind of pressure that's reasonably adequate for most occasions.

 

[OVERKILL]

Originally Posted By: Garak
Originally Posted By: OVERK1LL
What I find curious is why Europeans are given the option of running two different pressures based on how the tires are used, whilst the USA audience is given a single recommendation that sits half way (roughly) between the two Euro options....


That is odd. Any other Euro car drivers here see such a thing? My Audi didn't have that, but it was rather old.

Maybe the U.S. has one tire pressure listed the same way as all of North America is supposed to use one viscosity of oil.

Really, though, does yours have a TPMS? If that's standard in North American cars but perhaps not European cars, they might calibrate the TPMS for a middle of the road kind of pressure that's reasonably adequate for most occasions.


Yes, it has TPMS. But it is a TPMS you "set".

Basically, you put all the wheels at their desired pressures and then you calibrate the TPMS, then if any of the wheels get low, the system notifies you. So you can run whatever pressure you want and the TPMS won't care, it watches for deviations from whatever value you set, not some factory value.