New To BMW and Synthetics

Status
Not open for further replies.
He didn't say 40%, that was someone else.
wink.gif
 
Originally Posted By: weasley
Originally Posted By: riggaz
did I say huge?


A 40% change in fuel consumption is huge. I live in the UK and barely see a 1 or 2 point change (from, say, 41 mpg (UK) in the summer to 39 mpg in the winter). I use a/c in the summer when it's hot but not in the winter at all (save for a few 'seal conditioning' runs). The main factor in the winter is the cold starting, with thicker oil and a cold block that needs more energy to heat it up. Once at operating temperature the fluids will be more-or-less the same viscosity. If you are genuinely seeing a 40% change then you need it looking at.


Quote: The fluids are the same viscosity at operating temp?

Are you kidding? Try driving 100KPH down a highway at -30C with that temperature air blowing over your rear axle. You can stop anytime and touch the axle, and its not even warm. What viscosity do you think that fluid is?
 
Originally Posted By: Bluestream
Originally Posted By: weasley
Originally Posted By: riggaz
did I say huge?


A 40% change in fuel consumption is huge. I live in the UK and barely see a 1 or 2 point change (from, say, 41 mpg (UK) in the summer to 39 mpg in the winter). I use a/c in the summer when it's hot but not in the winter at all (save for a few 'seal conditioning' runs). The main factor in the winter is the cold starting, with thicker oil and a cold block that needs more energy to heat it up. Once at operating temperature the fluids will be more-or-less the same viscosity. If you are genuinely seeing a 40% change then you need it looking at.


Quote: The fluids are the same viscosity at operating temp?

Are you kidding? Try driving 100KPH down a highway at -30C with that temperature air blowing over your rear axle. You can stop anytime and touch the axle, and its not even warm. What viscosity do you think that fluid is?

OK, ca you repeat your question?
What temperature is then motor oil if you drive 100kph at -30c (I did many times, so please tell me it is not on operating temp).
 
Originally Posted By: riggaz
For one thing, MPG. My gas consumption goes up 40% in the winter and that is mostly due to thick fluids caused by the cols weather.



You might find it's due to the winter grade fuel as well. It's no way near as "pure" as summer grade fuel. We have a drop in mpg in England on winter fuel so it's probably much worse at your temps.


Yes i believe you did say 40% increase due to "thick" fluids in the winter.

Since a huge percentage of UK vehicles now spec on 5w30 i don't consider that to be a particularly thick fluid.
 
Originally Posted By: edyvw
Originally Posted By: Bluestream
Originally Posted By: weasley
Originally Posted By: riggaz
did I say huge?


A 40% change in fuel consumption is huge. I live in the UK and barely see a 1 or 2 point change (from, say, 41 mpg (UK) in the summer to 39 mpg in the winter). I use a/c in the summer when it's hot but not in the winter at all (save for a few 'seal conditioning' runs). The main factor in the winter is the cold starting, with thicker oil and a cold block that needs more energy to heat it up. Once at operating temperature the fluids will be more-or-less the same viscosity. If you are genuinely seeing a 40% change then you need it looking at.


The oil temperature would be vehicle specific at -30C

Quote: The fluids are the same viscosity at operating temp?

Are you kidding? Try driving 100KPH down a highway at -30C with that temperature air blowing over your rear axle. You can stop anytime and touch the axle, and its not even warm. What viscosity do you think that fluid is?

OK, ca you repeat your question?
What temperature is then motor oil if you drive 100kph at -30c (I did many times, so please tell me it is not on operating temp).


The oil temperature at -30C would be vehicle specific
 
Last edited:
Quote:
The oil temperature at -30C would be vehicle specific

So wait. Your claim is that at -30, if you drive 100kph you oil will not reach operating temp?
 
Originally Posted By: edyvw
Quote:
The oil temperature at -30C would be vehicle specific

So wait. Your claim is that at -30, if you drive 100kph you oil will not reach operating temp?


At -30 the wind chill on his diff and sump @ 70mph will be very, very bad so I'd say he is absolutely correct. That's why manufacturers usually give oil recommendations based on ambient temps because they know this happens.

So while your statement that at operating temp they are the same is true, his oils will never get to full operating temp due to his ambient temps.
 
Last edited:
Originally Posted By: riggaz
Originally Posted By: edyvw
Quote:
The oil temperature at -30C would be vehicle specific

So wait. Your claim is that at -30, if you drive 100kph you oil will not reach operating temp?


At -30 the wind chill on his diff and sump @ 70mph will be very, very bad so I'd say he is absolutely correct. That's why manufacturers usually give oil recommendations based on ambient temps because they know this happens.

So while your statement that at operating temp they are the same is true, his oils will never get to full operating temp due to his ambient temps.

That is interesting, considering that all cars that I drove and had oil temp. gauge, always reached operating temp even in colder weather.
All cars that I had, that were produced after 1990 had skid plate to protect sump, hoses, etc. Also, there is heat exchanger.
On short distances, of course it will not reach temp, but if you drive longer sure it will, especially in German cars that love to run hot.
 
Originally Posted By: riggaz
At -30 the wind chill on his diff and sump @ 70mph will be very, very bad

Based on what I've read before, machines do not feel wind chill. Wind chill is a term invented by meteorologist in relation to how human skin/body perceives a combination of temperature and wind.

With that said, I too observed slightly lower engine oil operating temps in cold weather on my old 2001 A4 1.8T that had an oil temp gauge. In the summer, it'd be around 190-200F. In winter (ambient temps below freezing), it'd be around 175F or so.
 
yeah wind chill is more of a figure of speech

Air does have a cooling effect when things move through it because the heat from said object is constantly being taken away rapidly. The radiator on your car works because of this.
 
I think if you go off piste with the viscosity then you really need to check your oil pressure is in the specified range to make sure you've got it right.
 
It's the difference between evaporative heat loss and convection. You get convective heat transfer with moving air (as well as still air in the presence of gravity) but since the components are generally not moist you don't get the extra loss from the heat of vaporization.

Originally Posted By: riggaz
yeah wind chill is more of a figure of speech

Air does have a cooling effect when things move through it because the heat from said object is constantly being taken away rapidly. The radiator on your car works because of this.
 
Yep kschchn is correct...wind chill is the effect if evaporating moisture that can mak the wet towel aroub yor neck cooler than the thernometer...an transfer way more heat than. Straight temperature difference would
otherwise do...about as much heat to evaporate a pound of water as getting it from freezing to boiling
 
Originally Posted By: riggaz
Originally Posted By: edyvw
Quote:
The oil temperature at -30C would be vehicle specific

So wait. Your claim is that at -30, if you drive 100kph you oil will not reach operating temp?


At -30 the wind chill on his diff and sump @ 70mph will be very, very bad so I'd say he is absolutely correct. That's why manufacturers usually give oil recommendations based on ambient temps because they know this happens.

So while your statement that at operating temp they are the same is true, his oils will never get to full operating temp due to his ambient temps.



Really.

We experience real -40c cold here in Saskatchewan. My charger runs the same oil temps whether its -40c or 26c like today,it just takes a bit longer to get there,so your mistaken in that regard.
 
Yep, it's all very application specific. Thanks to the skid plate, the G37's oil temperatures were hotter in -34 C this winter than the taxis' oil temperatures were in +34 C, running all day. The Audi 200, with the oil cooler, did have a noticeable difference between the seasons, but nothing insanely different, with the real change being the time it took to get to temperatures, as you indicate. My F-150, the taxis, and so forth had a bit more noticeable difference..
 
Status
Not open for further replies.
Back
Top