the mans right zinc is used to help break in engines.
i ran 5-50 full synthetic in my starlet once, the oil was so thin the valve train noise was ridiculous and tappets were horrible. it also leaked out of alot of places.
as for acceleration though the thing couldn't wait to jump off the tacho
i switched to a full synthetic 15-50 and its alot happier. it doesnt leak anymore either
