[ragon11]

I live less than 5 minutes from a highway. So in the morning, I get on this highway and go around 65 MPH. I have the chrono package so i have the extra information in the center. The coolant temperature is normal, but the oil temperature is still cold. When I am cruising, the oil pressure is much higher than it would be when it is completely warmed up. The oil pressure gauge is about 3/4 the way. I try to keep the RPMs down, but when going 65 MPH it turns a tad under 3k RPMs. Should i be concerned about the high oil pressure and warm up the car a bit more, or since the coolant level is normal I shouldn't be too concerned. I guess the question I am asking is, am I hurting the engine?

Andrew

[Penguinracer]

Hi Andrew,
I would say that you are not doing your engine any harm at all if you're running it at 3K rpm while the oil is still cold. Many car manufacturers today advise owners NOT to warm up their car by letting it idle - the reasoning being that at idle the oil pump is not working at full pressure & therefore not circulating oil to the valve train at the optimum pressure. They advise drivers to get in & drive straight away at normal revs.They're essentially saying that too much time at idle for a cold engine could lead to increased camshaft wear. The concept of warming up an engine really stems from the older days of motoring when metallurgy, lubricant & engine technology were not what they are today. All those different materials in the engine had different expansion rates, lower quality gaskets, & seals, thick oil with few additives etc.
A mechanically sympathetic approach is to perhaps go with a halfway house - allow the engine to idle for perhaps a minute before putting any load on it & then do what you're doing - drive at moderate revs allowing the oil pump to operate at full capacity while the oil warms up reasonably quickly. Your engine oil will take a lonng time to warm up if you are just running a cold engine at idle. A fully synthetic oil, especially one with a 0W cold viscosity rating is best thing you can do for your engine to all practical intents. Forget about pre-oilers & such like - they're not really necessary for daily use in temperate climes. They have their place - Alaska, Northern Canada may be! A bit like block heaters, great things but really only necessary in extremely cold climates.
Regards,
Tim

[Root Ginger]

Which is why MINI's come with 0w 30 oil as standard

[St00ge]

i just did my first oil change, and I filled it with 5w-30. Should i have put in something different? 0w-30 or 0w-40 ?

[Jon Chalk]

I think it will depend on how cold it is likely to get - if you're in a bit of Oz that never gets cold, probably OK. As penguinracer said above, the difference between 5W-30 & 0W-30 is only in their "cold" viscosity - 0W-30 will be less viscous (i.e. thinner) at low temps & will therefore circulate more easily in a cold engine.

[St00ge]

Quote: Originally Posted by Cooperama

I think it will depend on how cold it is likely to get - if you're in a bit of Oz that never gets cold, probably OK. As penguinracer said above, the difference between 5W-30 & 0W-30 is only in their "cold" viscosity - 0W-30 will be less viscous (i.e. thinner) at low temps & will therefore circulate more easily in a cold engine.

oh ok, i understand...well yeh the lowest i've seen is about 8 deg C here. What would you suggest? I know that BMW told me that they would use 5w-30....

[Jon Chalk]

Here in the UK, I would stick with 0W-30, not becasue the temps get cold, but mostly becasue I'm a coward & would stick to what BMW recommend in your country which is 5W-30 if I've read your post right, just in case.

The chart below just shows how viscosity ratings are used to choose an appropriate oil, from https://www.burtonpower.com/technical/tt_lube.html - which gives a pretty good (and not too techy) explanation.

[St00ge]

hmmm cool, thanks for that mate....just a quick question, what does the second number mean for the viscosity?

[n00b]

Lotsa good info here, in fact it's an overload..

http://www.bobistheoilguy.com/

I am running 5W-50 by the way, probably not the most appropriate but will be changing back to some 0W stuff when it gets a bit cooler. Besides, I ain't running those long life oil as BMW recommended.

[St00ge]

cheers Evan

[pocketrocketowner]

So you all know, while the 0 refers to "cold viscosity" and the 30 to "hot viscocity", the cobination and the fact that it is a systhetic oil (it would be nigh on impossible to blend a 0W30 mineral oil) give it a good measure of Fuel Economy.
A different, heavier grade either way penalizes you on fuel economy for a good 3 to 5 %.