Jason Knowles

Having 1000 mile service tommorrow 04STI .thinking of changing after 3000miles to castrol rs 10/60 synthetic.Is the oil main agent supplies in my case magnatech 10/40 semi synthetic really up to the job of 10000miles of abuse?

SL_WRX

From previous threads I have seen on here, from 1000 mile to the next service (ie 10k or 1 yr), you are better having a semi-synthetic oil as the engine is still bedding in. Then after that go for a good fully synth such as Castrol RS or Motul. My Subaru dealer uses Shell Helix semi-synth.

JohnD

iTrader: (5)

Stay with the Magnatec until the next dealer service then change to a good full syn. oil but not as thick as RS 10/60. Do a search for recent threads on the subject of oil grades
JohnD

corradoboy

As stated, a good semi for the next 5k or so, then at the interim change (if you plan to) switch to a good synthetic. If you drive hard (or track occaisionally) then a 10W50 will be good, for normal use a 5W40. Recommend Motul, Silkolene, Millers.

oilman

iTrader: (9)

Use a decent fully synthetic when you change and preferably an ester based one for the best protection. 5w-40 or 10w-40 is fine unless you are doing extreme things with your scoob.

Esters



All jet engines are lubricated with synthetic esters, and have been for 50 years, but these expensive fluids only started to appear in petrol engine oils about 20 years ago. Thanks to their aviation origins, the types suitable for lubricants (esters also appear in perfumes; they are different!) work well from –50 degC to 200 degC, and they have a useful extra trick.

Due to their structure, ester molecules are “polar”; they stick to metal surfaces using electrostatic forces. This means that a protective layer is there at all times, even during that crucial start-up period. This helps to protect cams, gears, piston rings and valve train components, where lubrication is “boundary” rather than “hydrodynamic”, i.e. a very thin non-pressure fed film has to hold the surface apart. Even crank bearings benefit at starts, stops or when extreme shock loads upset the “hydrodynamic” film.

Take a look at the thread "Lubricating the Subaru", do a search, there is plenty of healthy debate and info in there.

Cheers
Simon

corradoboy

Oops, just realised that I typed semi instead of synthetic for post 5k oil change but ignore me, Simon is THE MAN