Which engine oil should I use.

[Esho]

Hi all,

My car is due for a full service and I just need Some advice as to which engine oil is best suited for my car( semi synthetic or fully synthetic and/or which brand)
A bit of info about my car. It's a 2005 (MY06) liberty tuned by sti 2.0 litre 5 speed manual.It has done 117k.

Let me know if you need more info.

Any advice would be muchly appreciated


Thanks.
Esho

[triston]

how often do you usually change oil?

on my last change @100k(2008 tuned by sti) I used royal purple HPS 5w30 (i think), First time I have used RP, no complaints done ~4k since change

generally I change every 5-8ks

[fedaykin]

A full syn Nulon or Penrite will do the job. 5W-40 or 10W-40.

[BillyCorgi]

BEWARE of this thread on the Legacy GT Forum in the USA
http://legacygt.com/forums/showthread.p ... 73358.html

Subaru North America recommend a tighter oil change interval on Turbo vehicles.
Looking at these and other threads the root cause of failures is.....
(1) the turbo engines create greater amounts of particulates that get trapped in the oil filter (compared to N/A cars)
(2) the standard sized oil filter is too small to manage the quantity of particulates for long oil drain intervals.
(3) a loaded (clogged) oil filter will go into bypass when clogged and circulate unfiltered oil when clogged to prevent catastrophic engine failure.
(3a) a loaded clogged filter operating in bypass will have lower oil pressure and put more stress on the big end bearing lubrication (read spun big end bearings).
(4) the unfiltered oil clogs the fine oil strainer in the banjo bolt in the oil feed line to the turbo
(5) the turbo receives insufficient oil and fails.

For turbos, a shorter oil change interval is recommended (5k-6,000kays)
My recommendation is to ALWAYS change the oil filter before a spirited track day (and top up the oil level for the small quantity of lost oil)

You ALWAYS need to use a high quality synthetic oil.
You need to change the oil and filter often.
Do not do that and you are asking for Turbo failures and/or spun big end bearings.