I was wondering the same about the leaded/unleaded.

I run Leaded Race Fuel due to I run 4 strokes also.
http://www.vpracingfuels.com/page469675.html

Thanks motorgeek so basically the only difference between 110 leaded and 110 unleaded is price no big performance difference. And I should go non oxygenated unless I'm running drags. Would I be better off running 100 leaded for trails and then running 110 leaded oxygenated for drag races? Or should I just consistently use say 110 leaded non oxygenated for all riding?

Quadman8 is correct about the power potential of high octane fuel.  The octane rating is not a rating on the fuels power potential .  It is a rating on the fuels resistance to detonation. 

I have not found oxygenated race gas to increase the power more than about 1.5% when the jetting is optimized.  I have seen alot of holed and siezed pistons when oxygenated fuel was used and the jets were not right.

The BTU content usually goes up as the specific gravity goes down.  Some of the real high octane fuels are real light compared to pump gas that have high aromatic contents.

Gasoline is a cocktail of liquid hydrocarbons that has to have a specific gravity of about .68 to .75 and can produce 17K to 20K BTUs when burned.  These specifications are necessary for our carburetors and fuel injection systems to mix the fuel and air so that it will be combustible.  Basically, if the fuel is outside of these specifications the “jetting” will be too far off for engines that were designed and jetted for gasoline.

The universal BTU content for gasoline regardless of the octane rating, is 17,000 to 20,000 BTU per pound.  If the heat content is outside of this range, it is not gasoline.  If I remember correctly, methanol is about 9,000 Btu/lb, ethanol is about 12,000 Btu/lb and E85 is about 14,000 to 15,000 BTU/lb. 

The heat content of the fuel has nothing to do with its power potential.  The fuel mileage is directly related to the heat content.

An engine processes heat and turns a certain percentage of the heat to crankshaft torque.  About 30 % of the heat is turned into crankshaft power. The remaining 70% of the heat is expelled in the exhaust and dissipated through the cooling system.

An engine has to process the same amount of heat to develop one horsepower regardless what type of fuel it is using.  The heat content of methanol is about 1/2 that of gasoline and is the reason that the fuel mileage for methanol is approximately 1/2 that of gasoline.