4.3 litres with filter,I would be replacing the oil filter every time the oil is changed,they are cheap to buy anyway.I always add around 4 litres then use the dipstick to finish off topping it up.Start the engine,let it idle for a minute or two then let it sit for 5 minutes and then re-check the oil level.
Hang on!!! The oil capacity is 5.3 litres for an ecotec, says so in book and I always have to ensure that i have a bottle with some left over from the last change as a five litre bottle is not enough. Unless the earlier ecotecs had a smaller sump? But can someone confirm that last bit please.
I'm pretty sure the oil capacity on a VS ecotech is a fair bit less than a VY. The VY's I think have a larger sump capacity to enable an increase in the service interval from 10,000km to 15,000km. That said I'm not so sure about leaving oil in for that long. I always use a new filter. I find genuine parts are usually cheaper if you find the right Holden dealer.