Oil - Cold Weather Selection

[oilman]

In this cold weather, it is beneficial to use an oil that has good cold start flow properties as it will get to the parts of the engine that need it far more quickly.

The "w" number which means winter is the key here and the lower the better.

It may seem odd but a 15w or 20w will struggle to get around the engine in very cold temps and I would strongly recommend a 10w or better still a 5w for better cold start performance.

90% of all engine wear occurs on cold start because the oil get thicker the colder it is which causes engine wear.

These numbers explain what I mean and bear in mind that the oil will be the following thickness at 100degC (sae 40 = 14cst, sae 50 = 18cst and sae 60 = 24cst)

At 0degC these are the numbers (thick!)

Grade.................At 0C.........At 10C...........At 100C

0W/20.............328.6cSt......180.8cSt..........9cSt

5W/40.............811.4cSt......421.4cSt..........14cSt

10W/50............1039cSt.......538.9cSt..........18cSt

15W/50.............1376cSt.......674.7cSt.........18cSt

20W/50.............2305cSt.......1015cSt..........18cSt

If you are using anything more than a 10w oil, always warm the car properly before driving it as the oil needs time to circulate.

Just a word of warning really.

Cheers

Simon

[Ryan1985]

Does oil not just sit in the sump at idle when you turn it on though? Do you not need to drive it to get it circulating? If I woke up 2mo morning and switched it on and left it running while I was getting ready would that be better for my car?

I'm a novice btw!

[oilman]

In a short word no.

Oil is circulated the minute you turn the key.

Just don't hit the loud pedal until the engine has warmed up.

Cheers

Simon

[Karma Supra]

One would hope people don't do that anyway from cold!!!!!!! But I guess it takes all sorts. Most cars these days don't even have an oil presure guage and people seem totally unaware of what is going on inside the engine!!!

Out of interest Mr Oil man, what are your opinions on turbo timers? Good news or a total waste of time (I know people have very mixed views on them).

Form an oil temperature point of view as opposed to turbines speed ;)

[mikeb]

Out of interest Mr Oil man, what are your opinions on turbo timers? Good news or a total waste of time (I know people have very mixed views on them).

←

I'm not oilman ( ) but my opinion is that turbo timers are pointless. Just drive the last mile (or minute or so) off boost. It won't take long for a turbo to cool to a safe temp anyway, especially if it's water cooled.

If your car sits with the engine running whilst stationary, as the turbo timer counts down, then you are just getting the whole engine hotter and hotter. It doesn't receive any of the cooling air that it would do if you were driving along - even at 10 mph you are getting a reasonable amount of air circulation around the rad and engine.

I don't think there are any oils that can handle a the temps of a thrashed turbo if the engine is turned off immediately.

[oilman]

Well you do need to wind the turbo down, how you do this is up to you, take iteasy for the last mile, or turbo timer.

If you just switch of a thrashed turbo it will carbonise most oils.

Cheers

Simon.