Greg, I purchased some SyDiesel fuel from Hiper Fuels back in 2003. Cetane 63 and 20500 btu/pound. Sulfer free and will not oxidize. The winter of 2003-2004 I mixed up some fuel with kerosene and a batch with SyDiesel. Same percentages of ether, castor and ignition improver in both mixes. I used an reproduction Oliver Jaguar 2.5 cc late 1940's long stroke/side port design with many runs as a test engine. I used an APC 12/7 prop and a 1/2 ounce tank. I ran a couple of tanks of Olde English mix thru the engine just prior to test runs with the two fuels I mixed. I ran three runs with each fuel, alternating fuels each run. The SynDiesel required a bit more compression but I did not change the needle valve. Averages for the kerosene based mix were 4,900 rpm and 7 minutes and 51.66 seconds on the half ounce tank. With the SynDiesel I got a 5,100 rpm and 6 minutes and 9 seconds. Since at the time I was testing fuels for A Texaco I stuck with kerosene. Recently I tried a couple of different engines with the SynDiesel mix. One turned up a bit better with the SynDiesel and the other about the same on both fuels. I think a Drone was one of the two I tried, but do not remeber the other engine. I just checked Hyper Fuel's web site and the price of their SynDiesel has gone thru the roof. www.hiperfuels.com I have purchased methanol from them in the past to mix FAI glow fuel. Jack