Forged piston oil usage
 

Hi guys, I've got a Wrx hatchback and it got rebuilt in September last year with forged pistons. Done 3500 miles since and it's used 5L of oil, been back to the builder and they said that's normal for forged pistons. Is that too much and if so hows it using that much?

mine was built last year with mahle pistons ona cdb and honestly has,nt used one drop of oil probably done about 4000 miles at 500+ had 3 oil changes since due to various jobs done on car and servicing- ran mine on 10-50 millers since built.

my last classic on wossners drank about half a litre per thousand miles-did.nt have a catch can on that one so used to throw a lot of oil into the breather system-noticed a good improvement going from 10-40 to 10-50 oil though -the thinner oil seemed to be used much quicker.

Bores been honed to big is my opinion and too small of s piston contributes to oil usage.
If built correctly it shouldn't use a drop once bedded in after rebuild.

With that sort of oil usage, I would have a compression test and cylinder leakage test done to check the 'internal health' of the engine.

if the gaps are too large they will rattle when the oils hot or cold
-was this a "proper rebuild" or just drop in pistons in existing bores?