I've been running my 30 year old 2-cycle 15HP Nissan for years at 16oz. oil (half quart, easy to measure) to a 6 gallon tank which comes out to 48:1
The manual calls for 50:1 or 15.4oz to 6 gallons for a new motor.
It doesn't smoke a lot, and it is the nature of the beast, but I'd like to cut...