10w40, any brand will be better long term than an expensive lighweight oil.

The only time you need to run a 0w/5w oil is on a dyno day for the extra few short lived kw's.

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Long live the WRC

genuine oil is actually 5w/30 for wrx/sti

i always use genuine oil in my car with 130,000kms and doesnt burn much oil
a thicker oil can also give you worse fuel economy

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2000 WRX - Grip King
1997 Sileighty - Gate Monster

5/30 is an option if you want to spend more money and it's a synthetic oil where as the subaru recommended 10w40 is semi synthetic. If your car is burning oil run the thicker 10w40

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Marti


Car: C Red S13 Silvia 2.3l 400+rwhp-SOLD
Daily ae82 4age corolla (light mods)-Sold
Daily:SWB GQ Patrol
Will be a 03-04 STI next

1. Put the oil grade as specified in your user manual / or specified by your engine builder.

2. The number before the W (for winter, not weight - damn fast and furious) is your cold start oil type. Once the engine is up to temp it doesn't have much to do with the operation of the engine/oil. If your car is burning oil when running, changing from a 5W to 10W will do bugger all, you need to look at the last number for a thicker oil.

Oils are essential life blood of your car, don't just go changing things without researching it first.

Good starting point is wiki Motor oil - Wikipedia, the free encyclopedia

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[COLOR="Gray"]550Nm off a 2L... Just wish it was in the dak dak...[/COLOR]

crawl3r what oil did u end up using?? and what were the results?

I've been on the 5w40 and I'm thinking of going to 10w50...

5/30 is too thin for our climate for long term protection. Thin oil helps keep exhaust emissions low and promotes slightly better economy all at the expense of engine protection. EJ25's also have a different sump that has the oil level closer to the crankshaft, this can lead to increased windage and oil consumption.

As something like 70% of wear occurs at start up and in a cold engine, the lighter the oil, the quicker it will run in to places where lubrication is needed, providing the best protection. My understanding is that the determining factor is oil pressure. You should run the lightest oil you can which maintains oil pressure within the recommended parameters. A car with more engine wear will need a thicker oil in order to maintain pressure and/or not burn oil.