I used to run single weight oil (Aeroshell 80 in winter 100 in summer).

Last year I fell for the marketing hype and put Aeroshell 15/50 in.

My engineers have just told me that they have been advised by the propshop they use not to put multi grade in with our three blade props as it make the props to use his words "sluggish".

My oil consumption has gone up from about 5 hours to the quart to about 3 hours/ quart although this might have something to do with a persistent leak I just can't get rid of!

Anyone heard bad things about multi grade oil and props?? I did hear something about switching high time engines to multi grade being a bad thing.

David T

G-OLFT
14274