I started using the Lucas to see if I would get any improvments in engine noise originally, I had about 2000 miles on my big bore and never got more than 38.whatever MPG on a tank after the upgrade. It took a couple of tankfuls to see an MPG improvment but I am getting 40-43 consistently now, that 42.85 was the high end and most of the time it is in the mid 40's now. I commute 55 miles each way every day and there is little if no difference in my use of the throttle on my commutes as I am going with traffic at 65-75. My mileage on weekends is usually at the lower end of the spectrum as I am on the throttle more then and on back roads a lot more. That has been my experience and I am going to do my commutes next week without the Lucas and see if my MPG drops back, not using at all this weekend either to work it out of the system to try and get a good test.I don't think thats true at all. there are a lot of arguments one could come up with against that notion, but one is MPG. Member andrew65 was getting 38mpg and after pouring some of the lucas stuff in got 42.85mpg. Thats a huge difference that I never see on mine except when i compare flogging the bike and riding like grandma. So unless he tested it while riding very differently than he does, there would be no way to explain a 5 MPG improvement. But more importantly there are a lot of people who report great improvements in MPG. We shall see. I know my bike's mileage like the back of my hand, so I will know if this works in that regard. And if it does then the only reason that could be happening is improved lubrication of the upper cylinders which any way you look at can only be good. On the other hand if you are right i'm out 4 bucks....i think i can still eat tomorrow.