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..........9cS t

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

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

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

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

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

 

Thanks

 

Could this be what is causing some of these tapping noises?

http://bbs.scoobynet.co.uk/showthread.php?t=472962

 

May be a factor, what oil are you currently using?

Cheers

Simon.

 

Sorry to drag up an old thread but....

Hey simon, could you include the qualities of Castrol RS 10w-60 and Shell helix racing 10w-60 in that table as a comparison?

As I belive the cold properties above 10degC of both are no better than a 15-50w or 20-50w multigrade (or even a 40 monograde). Meaning their cold ratings are somewhat misleading. What info I have is sketchy at best, so it would be nice if you colud confirm or debunk my theories.

Cheers

 

I don't have the exact numbers but any 10w-60 will look in the region of this:


...........................0degC.................. ..10degC....................100degC

10w-60................1000 +/-...................650 +/-...................24

It's the thickness at 100degC that's my worry, it's still a 10w afterall.

Cheers
Simon

 

You do seem to worry about 10W/60 Oils Oilman ... I see you posted about it on another forum .. you wouldn't recommend this thick then for the UK?

I think 50 is too thick although I know that you recommend it .....

You would hesitate about using Millers 10W/60, I take it?

Could cause damage? maybe Big End failure even??

Pete

 

Possibly pete, that's why we service nearly all our customers cars with Millers 10w/40, and put the 10W/60 in the race car!

 

It's nothing to do with UK as we are not talking about cold start here, 10w is fine for the UK.

It's to do with engine tolerances and oil temperatures/oil viscosity.

Most Subarus have oil coolers and therefore the oil doesn't get to enough temperature to justify it. OK in some cases an sae 50 would be warranted but an sae 60 will remain too thick for the engine at 70-90degC sump temperatures.

This causes viscous drag, which leads to friction, heat and wear plus lower BHP and poorer fuel consumption.

Worst case with an oil that is too viscous is that it can lead to cavitation and slugs of air being fed to the bearings.

Cheers
Simon

 

A 300hp (remapped) newage STI can get the oil considerably hotter than 90ºC in no time at all, even in the current climate.

 

As I said in some cases the move to an sae 50 would be warranted to give the required 14cst viscosity.

Cheers
Simon

 

Why won't you allow a customer to have whatever Oil they wish in their own cars??

I am VERY curious, I cannot think of one other dealer that takes such a stance??

You are saying that if a customer wants to use MOBIL, Silkolene, Castrol R they can go elsewhere ...............

Is it that the other Oils are crap in your opinion? Or just not as good as the Millers?

Pete

 

Well pete, i've still got my head in a hole over this oil debate........
But like you and unlike many others i still have the cash in my pocket,
The cash i save on every oil change!

 

Too many vested interests involved I'm afraid for them to admit that the Oil Subaru recommends is actually perfect for the car!!

I have no axe to grind, no money involved, no business ....... just a desire to see justice done and the members of ScoobyNet to stop being scared ****less into buying expensive products that they don't need!

Pete

 

Pete, we do lots of Subaru engines and boxes (as well as some other race/turbo builds) and don't tell our customers they have to do anything, however after just a few years of "messing" around i do feel that we have amassed an amount of info that may help them................

also after using various oil suppliers over the years we have settled with two that do exactly what they say on the tin and we believe offer the best quality/protection/range/value in the market place.................MOTUL and MILLERS OILS

and to answer your question above i personally have never encountered any engine damage caused by a 10w60 oil even though certain parties (including yourself) continually question its use

alyn

 

Hi Alyn

Did I say that you tell customers what to do?

Did I say that Millers Oils are crap? That they do NOT do what they say on the tin?

Did I say that 10W/60 Oil is not advised (if you read what I say, you will note that it was Simon, Oilman, who was questioning it - he says use no thicker than 50)

I am puzzled by your post actually....??? not quite sure what point you are trying to make?

It's interesting that you use Millers because it does what it says on the tin .... I use COMMA because it too does what it says on the tin - not quite sure what that proves one way or the other?

Do you have links to Zen Performance at all? then I may be able to understand where you are coming from??

Pete

 

Castrol ep 90 sorted


Mart

 

Pete,

Alyn and I share the same preferences in oil. I used to run my own car exclusively on the Motul, but the Millers is just as good (in terms of oil pressure control when hot, and after time) as the motul in my experience, but it's cheaper.

Paul

 

I'm glad I got my answer before Pete woke up after his late afternoon snooze

 

That wouldn't be KY Oil ...... would it

Have you both been to see breakback Mountain yet??

Pete

 

Pete,

If it's any consolation, my wife just said of you, and I quote:

"He does try really hard, bless him"

Which I thought was perhaps a little generous.

Paul

 

Tell her that I am available for weekends, while her man and his mate are changing oil according to the **** Procedure

Pete

 

Pete, someone posts the word oil and it sticks to you like cat s**t to a blanket.
Were you a can of GTX in a previous life? or does oil just float your boat

 

Add my posts up, add the other posters up and then come back and beg forgiveness

Pete

 

15K worth of posts and most about oil, but its a free world

 

1887 posts and you are a fully fledged IDIOT

Pete

 

Thats a little harsh, we have only just met, just wondering why you like talking about oil so much?

 

Not harsh at all considering your introductory post:-

"Pete, someone posts the word oil and it sticks to you like cat s**t to a blanket.
Were you a can of GTX in a previous life? or does oil just float your boat"

If it's too hot in here use the door

Pete

 

You just seem to have this thing about oil why do you get so worked up about it?

 

Why do YOU get worked up about ME getting worked up??

Answer that and therein lies your answer from me ......

Pete