When I first started looking at them, I had just begun playing with jet sizes to lean out the average running of my engine. I was hoping to get from the 9mpg to say 12 or 13. Well that never happened. But what did happen was I got to 11 mpg and got a much happier engine. Since this was an obvious advantage, it only made sense that if the Tempaflow could keep it running crisp from -20 to +10 without getting gas on my hands it was worth trying. The cool part is, the whole thing revolves around this plastic screw. It is made of derelin (?) or some such thing. It has very precise expansion and contraction properties which Holtzman mapped against temperature. They put it in a tube and use it to manage float bowl pressure to lean and richen the fuel mixture. And the damn thing works. I get a 22% increase in fuel economy. Lets see 22% of $1.75/gal is $0.385/gal @ 11 mpg is $0.035/mile, paid $157 for unit, so I need to ride 4,485 miles to pay for it. Installed it last year and rode 2,500 miles so I have to ride another 2,000 miles or so this year and I'm in the clear. COOL, I gotta go tell my wife the good news, Bye![^]