[Billfitz]

When I was in Calgary back in '74 Canadian gas prices were lower than in the US, and the Canadian dollar was around $1.04 US.

[HighlandPete]

BMW vs. Continental.

Also remember BMW will have recommendations based on the specification of that particular model and options. I've noted that not all door plate pressure stickers are equal, even for a given model in the range.

I always start with BMW recommended pressures, and work from there. Typically end up running a couple of extra psi, than the 'normal use' recommendation. This gives me the best balance for performance criteria and even wear rates.

BTW, the Continental figures do look high to me. Looks like a set of ECO pressure recommendations.

[Billfitz]

Maybe, but that being the case the BMW recommendations aren't CAFE based, and a couple of extra pounds of air works just as well in that regard as changing their oil recommendation from 5W-30 to 0W-20. That's what leads me to think it's more ride comfort oriented. While on the subject, those who don't think the LL branding isn't about the money haven't been paying attention. BMW changed suppliers again, this time back to Castrol.

https://www.castrol.com/en_us/united...-supplier.html

[eleven11]

Originally Posted by Skyhigh

There are winter tires (snowflake, M+S) and summer tires...

My understanding is that M+S generally applies to all-season (which is noted on the OP's vehicle). On the other hand, a snowflake or "Three Peak Mountain Snowflake" applies to a true snow tire (noted on Continental's site, but not specifically on the vehicle).

[Billfitz]

3PMSF indicates the tire meets required performance criteria to be considered severe snow service-rated. Some all season tires have this rating. I just got Michelin CrossClimate 2 because they do, and they're a top performer in wet and dry conditions as well.

[Skyhigh]

Originally Posted by eleven11

My understanding is that M+S generally applies to all-season (which is noted on the OP's vehicle). On the other hand, a snowflake or "Three Peak Mountain Snowflake" applies to a true snow tire (noted on Continental's site, but not specifically on the vehicle).

That is correct.

Generally the consensus is that there are only a few reasons to drive all-season tires all year long as they are compromised at both ends of the environmental conditions range.
- Climate which barely includes temperatures below +7 degrees Celsius and above +25C (and clearly no skiing as hobby )
- Laziness / Negligence
- No need/desire for performance driving

Some claim it is cheaper this way but that's not really true. You still drive the same kilometres per year, but instead of distributing them on 2 sets of tires (made for the corresponding conditions) - you put them down on a single set, which will need to be replaced twice as sooner.

I just bought new winter tires for my Audi. The previous set I purchased back in 2013…

When I was a child, all-season-tires were the default. Many didn't even know there is such thing as Summer and Winter tires or considered it an overkill. People know better now and it is extremely rare that someone even mentions all-season…., even more still drive them. In Europe that is. Not to mention proper winter tires are a requirement in many countries for the winter season.

There is no such thing as a universal screw-driver.

[MidtownMike]

Originally Posted by eleven11

My understanding is that M+S generally applies to all-season (which is noted on the OP's vehicle). On the other hand, a snowflake or "Three Peak Mountain Snowflake" applies to a true snow tire (noted on Continental's site, but not specifically on the vehicle).

Continental Wintercontact TS830P have both the 3 Peak Snow Flake as well as M+S on them. Didn't feel like going outside to take a pic of mine, so here's one I found of a TS830P:

[eleven11]

Originally Posted by Skyhigh

That is correct...

I agree with your thoughts on All-Season. I suppose there are some drivers who have mild winters and are non-performance oriented where they are acceptable. I subscribe to seperate Summer/Winter tires for my personal climate: Michelin PS4S Summer , Michelin Pilot Alpin PA4 Winter.

Originally Posted by MidtownMike

Continental Wintercontact TS830P have both the 3 Peak Snow Flake as well as M+S on them. Didn't feel like going outside to take a pic of mine, so here's one I found of a TS830P:

Thanks for sharing. What I was suggesting is that the pressures listed on Continental's website are for a 3PMSF tire, and therefore perhaps higher as a result. On the other hand, the listing on your vehicle is the same tire dimension, but for M+S (and not necessarily 3PMSF). Thus, the pressure is lower. Again, this is just a thought.

[MidtownMike]

Originally Posted by eleven11

Thanks for sharing. What I was suggesting is that the pressures listed on Continental's website are for a 3PMSF tire, and therefore perhaps higher as a result. On the other hand, the listing on your vehicle is the same tire dimension, but for M+S (and not necessarily 3PMSF). Thus, the pressure is lower. Again, this is just a thought.

This could well be possible, but not sure if it makes sense for BMW to single out M+S tires on the sticker but not winter tires?

I also thought of the possibility that Continental's chart may assume a tire workshop temperature of, let's say 20° Celsius (room temperature), whereas BMW's door frame sticker may assume a wintertime outside temperature of around 0° Celsius. Tires pressure decreases with lower temperatures, so it makes sense that you should "over-inflate" winter tires at room temperature to have "normal" pressure under typical winter driving circumstances.

[agentorange]

Those Conti pressures are stupid high. Must have been recommended by the brain donor at my local dealership who always sets my tires to 41 PSI all round. It's 32F 36R on the door placard.

[Skyhigh]

Originally Posted by MidtownMike

This could well be possible, but not sure if it makes sense for BMW to single out M+S tires on the sticker but not winter tires?

I also thought of the possibility that Continental's chart may assume a tire workshop temperature of, let's say 20° Celsius (room temperature), whereas BMW's door frame sticker may assume a wintertime outside temperature of around 0° Celsius. Tires pressure decreases with lower temperatures, so it makes sense that you should "over-inflate" winter tires at room temperature to have "normal" pressure under typical winter driving circumstances.

Keep in mind that even in the winter, your tires are always appreciably warmer than the environmental conditions (once you start driving)
It can be checked easily in the tire pressure and temperature monitor, but I reckon they get to around +5 degrees after some driving even when the outside temp is say -5.

The result of friction + heat from breaks, etc.

[MidtownMike]

Originally Posted by Skyhigh

Keep in mind that even in the winter, your tires are always appreciably warmer than the environmental conditions (once you start driving)
It can be checked easily in the tire pressure and temperature monitor, but I reckon they get to around +5 degrees after some driving even when the outside temp is say -5.

The result of friction + heat from breaks, etc.

Agreed. That is why I thought that the door placard may mention lower pressures as they are meant for "cold" tires. When the car is driven for some time the temperature will rise and pressure may increase to something closer to Conti's recommendation.

General consensus is that one should add 0.3 bar to the pressure when inflating tires on a car that has been driven for >5 km or >15km.

[HighlandPete]

Originally Posted by MidtownMike

Agreed. That is why I thought that the door placard may mention lower pressures as they are meant for "cold" tires. When the car is driven for some time the temperature will rise and pressure may increase to something closer to Conti's recommendation.

General consensus is that one should add 0.3 bar to the pressure when inflating tires on a car that has been driven for >5 km or >15km.

I'd be surprised if Continental are recommending a warm pressure setting, unless clearly specified for that chart.

BMW recommendation will definitely be cold tyre temperature settings. Summer or winter tyres.

[MidtownMike]

Originally Posted by HighlandPete

I'd be surprised if Continental are recommending a warm pressure setting, unless clearly specified for that chart.

BMW recommendation will definitely be cold tyre temperature settings. Summer or winter tyres.

To my understanding pressure recommendations are usually calibrated at 20 degrees Celsius (68 F), which is "cold" tire temperature in many regions across the world in non-winter season.
This could be the case for Conti chart as tire fitters will ususally mount tires in a heated workshop at around 20C/68F.

For BMW door sticker, it does not make sense to give 20 degree Celsius pressure for winter tires, because who has winter tires on their cars at 20 degrees? Makes much more sense to indicate cold temperature at typical usage circumstances (inflating outside at a gas station), which will be closer to 0C/32F.

Anyway, this is getting very speculative, and unless someone from BMW or Conti would get involved in the discussion, it will remain a guessing game...

[HighlandPete]

Originally Posted by MidtownMike

To my understanding pressure recommendations are usually calibrated at 20 degrees Celsius (68 F), which is "cold" tire temperature in many regions across the world in non-winter season.
This could be the case for Conti chart as tire fitters will ususally mount tires in a heated workshop at around 20C/68F.

For BMW door sticker, it does not make sense to give 20 degree Celsius pressure for winter tires, because who has winter tires on their cars at 20 degrees? Makes much more sense to indicate cold temperature at typical usage circumstances (inflating outside at a gas station), which will be closer to 0C/32F.

Anyway, this is getting very speculative, and unless someone from BMW or Conti would get involved in the discussion, it will remain a guessing game...

BMW warn of the workshop temperature setting, (difference between workshop and ambient temperature) and customer notification if necessary, in their data for the latest RDCi system. Therefore just go with BMW's cold (outside ambient temperature) setting recommendations for your specific vehicle, you won't go far wrong.