Oilman

If the car is 2000 onward, unmodified and used as a daily driver then 5w-40 synthetic would be the best option.

Cheers

Simon

Yep, that's me.

And...................5w-40 in a 2000 onwards.

Cheers

Simon

He's amusing but dangerous IMHO.

Cheers

Simon

Paddy,

It varies depending on year.

Pre 2000 it's around 14-18cst and post 2000 its 10-14cst.

Cheers

Simon

I'm not looking for an argument either, just trying to help.

My speciality is oil and not only is this my profession but I use proprietory databases (subcription only) to research the best oils for all types of cars from vintage right up to date.

I can tell you that regardless of your results, this oil is not the best grade for your car. Quite simply it's too thick.

There are reasons why thick oils are not good for your car but the most important one is wear caused by heat which is caused by friction due to the oil being too thick. Added to this, dragging an oil around your engine that is too thick causes a reduction in BHP at the wheels.

So, why is this oil too thick?

Well, the important thing is, at what (sump) temperature is the oil at a viscosity that suits a modern high-RPM engine.

Present day designs are more than happy on an oil viscosity of 10 to 15 cSt. (But many are OK on less than 10.) 30cSt is too high at high RPM. It can lead to foaming, air entrainment and cavitation.

............Temp. for 30cSt (Deg. C).......Temp. for 15cSt.......Temp. for 10cSt

5W/40..................71...........................90........................117...............

10W/40................70...........................99........................118...............

10W/50................80...........................109.......................130..............

10W/60................89...........................119.......................142..............

This shows that for example a 10W/40 is perfectly adequate for all engines except those that run an unusually high temperatures.

What you also need to consider is at 100degC oil temperature an sae 40 is 14cst, an sae 50 is 18.5cst and an sae 60 is 24cst, these may not seem big differences but calculated as percentages, they are.

I hope that these figures at least give some insight to what actually happens to the oil inside your engine at different temperatures.

Finally, do I recommend 10w-60? Yes I do where warranted but there are few cases in which it is actually necessary and these are mainly based on extreme oil temperatures and by this I mean in excess of 140degC for prolonged periods.

You see, owning a Subaru and not being an engineer actually has nothing to do with recommending the correct oil when it's your profession

Cheers

Simon

That sounds awfully like the Castrol Marketing blurb.

It's your car mate, use what you want

Cheers

Simon

How does that work when there is no mention of sae 60 in the handbook or recommendations.

Cheers

Simon

I don't, I run something different but Japanese of course.

Cheers

Simon

Look for an sae 50. Either 10w-50 or 15w-50.

Cheers

Simon

Stick with an sae 50 tops.

Either 10w-50 or 15w-50. 10w-50 will give better cold start protection.

Cheers

Simon

I don't wish to get into a war of words with you either. I just felt that you were too quick to judge me without knowing anything about me

Cheers

Simon

Matt,

Which model is your car.

Carl,

Perhaps you'd like to catch up with me at Rotorstock (mon) or any other show this year on my stand just to see that I'm for real!

What question have I avoided and why Motul from Alyn and not me? Is that because I recommend 5w-40 and he 15w-50 I wonder?

What cut and paste are we talking about? Am I not entitled to post articles that I have written myself or others that I have permission to from the author?

I feel it's unfair to judge me if you don't know me, so go on, come and meet me!

Cheers

Simon

I would consider 5w-40 as the best option for an 02.

Cheers

Simon

You have a lot of choices. I would recommend a good 5w-40 unless the car is modded.

Look at my Spring Oil Offers thread.

Silkolene PRO S 5w-40 and Motul 300V 5w-40 are very good ones but I have plenty to suit all.

Cheers

Simon

In a manual box I would use 75w-90 semi or fully synthetic.

Cheers

Simon

Would recommend Silkolene PRO S 10w-50 for your car.

Cheers

Simon

I personally wouldn't recommend an sae 60, it's really too thick and will generate excess heat in the summer or on the track. I recently did a "group buy" here and am prepared to do others.

We recommend Silkolene PRO S 10w-50 or 5w-40 depending on usage, mods etc.

It's also a very good "true" synthetic product which is thermally stable at high temperatures.

Cheers

Simon