It's the same principle as what you'd expect from hand spraying. Smaller nozzle/droplet size, bigger pressure equals more drift or easier drift and atomization. Yeah....with 1/3rd gallon tips at 40 PSI and 20" off the ground at 5 mph you can get drift pretty easy with wind. Less so with 1 gallon tips especially since you won't be able to maintain big pressure with a small pump on a ride on and the droplet size on a 1 gallon tip doesn't atomize as much as a smaller tip. You already know all this I assume.