djwrx

my 53 plate goes too subaru too be serviced and they use shell helix 10w40 but when i look at oilman recomendations they say 5w30
anyones thoughts on this please
thanks

TonyBurns

iTrader: (3)

Go for a nice 5w40 fully synthetic
I would only use (though not my preference) a fully synthetic 5w30 oil and not semi synthetic.
Shell helix ultra 5w40 should be available from your dealer

Tony

djwrx

cheers dude

Wagon Gaz

iTrader: (18)

What Tony says I only use 5w/40 full synthetic on mine. Better protection on a cold day.

pslewis

Do what Subaru say ..... if they thought 5W-40 was any good, they would specify it .... they don't.

Ignore Oilman and the Hobbyists .... vested interests should be ignored

Stick with 10W-40 and all will be well ...

nick172sport

iTrader: (6)

as above what subaru state why use synthetic if you start using it youve got to keep using it

TonyBurns

iTrader: (3)

They do specify it Pete

Tony

The Dogs B******s

10W-40 in mine

pslewis

10W-40 Semi ...... use anything else at your peril .... 5W too thin .... don't even consider 50 as it is power sapping treacle!

TonyBurns

iTrader: (3)

I would read your manual again Pete they start at 5w30 (though only for extremely cold temps as indicated by the warning) all the way to a 15w50 oil for our european climate
5w40 is also actually recommended though they do not recommend any 0 weight oils.

Tony

fmp

iTrader: (7)

Zen filled mine with Millers CFS 10W60 fully synthetic.

Not cheap.

But i trust what Zen would supply, so you can stick your 5w40 lol!

TonyBurns

iTrader: (3)

Its great when you buy in bulk
a w60 is like treacle, the 5w40 provideds better protection that it so i shall stick to it

Tony

KINGTIGER

I use Silikone 5/40 fully Synthetic as advised by Oipe Oils.
But as I'm using this oil now will I have to keep using it or will it be ok to use 10/40 on next service.

pslewis

60 60!!!!

That is some real thick treacle ****!!

I'm surprised the starter can start the damned thing!!

That is amazing - the power you are sapping away is huge!!

Get it out and refil with the proper stuff immediately!!

Staggering, quite staggering .......

scooby1929

iTrader: (1)

If you think its like Treacle then you have never seen the inside of an engine!!

pslewis

I was looking inside engines when your pappy was still in his nappy!

60 is madness .... real madness - I wouldn't even put that in the old Ford Anglia I had in 1966!!

scooby1929

iTrader: (1)

Its the first number ie the 5W or 10W that is important on cold starting!!
The second number refers to the temperature protection. A Subaru with its turbo will run a lot hotter than your ford anglia. Hence oil breaks down at very high temperatures so the 60 gives better protection when the engine is raced or rallied for sustained periods

pslewis

I quite agree ... when raced or rallied - NOT, repeat, NOT when used in road going engines!!

In an engine running at normal temperatures the 60 oil is like sludge/treacle .... truly awful crap for the engine!! 40 moves easily to the parts it is needed.

Is the OP's car a true rally car used in races?

TonyBurns

iTrader: (3)

A 60 will not protect as well as a 40 at 100 deg c, at 140 deg c it will protect the engine better than a 40 but then again your engine would have let go before then

Tony

scooby1929

iTrader: (1)

One of the most popular oils used in Subarus is Millers. If you ring their technical department and ask what oil to use they will suggest either a 5W 40 or a 10W 60. If the car is modified or doing the occassional track day they will tell you to use the 10W 60. They also say than the 10W 60 can be used in just every day driving.

This talk of it being like treacle is utter nonsense. The last time I changed my oil I did it when hot as you do and what came out certainly was not treacle in any shape or form.

pslewis

Treacle to an engine it certainly is ....... I have experienced the difference in an engine with thick sludge of an oil .... and what that engine was transformed into when the oil put in was thinner when hot.

The difference was like a clapped out bag of spanners against a sewing machine!

And, if Subaru say that their engines run best with 10W-40 ... then that's what's best for them!! Millers don't make engines ... they sell Oil ... and, maybe, the 60 Oil returns them a very healthy profit? Waiting for a numptie, or two, to wander by Just a thought ......

tim's wrx

I've got the same car and my Subaru manual says that 5W30 is "preferred". So on that basis I feel justified using the Subaru recommendation. Experiment with other types of oil if you wish!!

scooby1929

iTrader: (1)

Well they sell both so not sure about that!! Yeh Subaru do make engines but what happens when you modify that Subaru engine to say 500bhp?? Subaru also say to use 5W 30 semi synethic?? Very few would use this.

pslewis

You shouldn't be messing about with these engines if you don't understand the basics of oil technology ....... the questions of 'Which Oil?' are asked by those who are driving standard/lightly modified engines.

Which, without exception, should have 10W-40 Semi in them.

An owner running 500 BHP would not come here to ask about Oil ... they would know - or they shouldn't be touching ANYTHING to do with engines

TonyBurns

iTrader: (3)

Do you understand at 100 deg c that a 60 rated oil is about 50% thicker than a 40 rated oil?
thats drag on your engine, thats the molecules not providing as much protection, and consdering that your car runs around 90-110 deg depending on the driving (110 being ragged and 90 being driven normally) its alot of drag.

Go have a look at a chart for viscosity weights, see how bad a 60 is in your subaru (unless you have 500+bhp).

There is another test though it shows the difference in cold weights, it will be valid for hot weights too and that is a tube with oil in, all different cold viscosities, a 0, a 5 and a 10, same hot weight, if you want to see the difference in thickness (and trust me you do ) do this with a same weight ballbearing in all 3 tubes!

Tony

Wagon Gaz

iTrader: (18)

The only difference between the 10w40 and the 5w40 is the 5w gives you more protection at colder temperatures, ie the -10 type of stuff we have just been through. The high end viscosity is just the same.

scooby1929

iTrader: (1)

What I also cant understand how places like Zen performance, Greenwood Race Developments,Roger Clarke and other top Subaru specialists all use 10W 60 if it was not suitable?? Have to be honest tho did not realise a 60 rated oil is 50% thicker than a 40.

I certainly dont have a 500bhp engine was just using that as an example!

pslewis

60 is 50% bigger than 40 ... so, it follows that a 60 will be 50% thicker at 100 Degrees! That's a lot of drag, a lot of treacle and a lot of lost power!

Maybe there is a bigger profit on selling 60 Oil? It could really be that simple - it certainly isn't good for a road engine!

tim's wrx

Interestingly my Subaru manual gives the following recommendations for severe driving conditions based on standard 2005 2 litre WRX:-

API classification SL or SJ

Viscosity 30, 40, 10W-50 or 20W-50