As gas prices rise close to $4 in my area, I have begun my search for alternatives. Being eco-friendly, I tried this product as a carbon-neutral, renewable, non-petroleum based, earth-loving gas substitute. I am absolutely outraged that my Hummer's mileage dropped to near zero and began foul-smelling backfires. I have now decided not to use it in my Gulfstream jet either. Until they get the bugs out of this fuel I will not buy the product again.