I'm from Malaysia & I'm using the 165ps ( from the Celica ST183)engine in my ST150 Corona. I do agree that's rather noisy in the mornings but I was thinking that it may be due to the valve train components i.e. the tappets instead of the pistons. I'm using Mobil 1(5W-50) but I'm not really bothered by it as I allow about 3-5 minutes of warming up before I drive it.