The only difference I noticed whiled pulling with bio (B100) was almost no smoke at all compared to #2. Like stated above the engine is quieter, and smoother. You can go back and forth with no problems, I use B20 in the colder months and B100 when it warms up. From what I have read B20 does not change #2 as far as the gel temps are concerned that much, it's actually almost the same. I do run an anti gel with the B20 just incase and as far as B100 goes if it gets below 27* you can wind up with some gelling issues. The only other thing to do is watch your fuel filter, bio is a natural solvent and will clean the crud out of your fuel system. Also with B20 you will not need any kind of lubrication additive, bio has twice the lubricity of #2.