I am a lady truck driver who has driven consistently for about 10 years. I became an owner operator in 1996. I bought my 1993 KW T-600B, with Detroit series 60 engine in 1996, used, with 410,000 miles on it. It had been run hard and I had no idea what the maintenance had been prior to my purchase (it's an old Prime, Inc vehicle). I had used Lucas Fuel Additive previously in company trucks and knew it increased fuel mileage. So when I bought my KW I wanted to give myself a fair chance at success by giving it the best. I have used Lucas Fuel Additive with an increase of 0.5 mpg and for its benefit as an upper cylinder lube. I also use Lucas Oil Stabilizer treatment, 3 gals to the service since I bought the truck, until it reached 1 million miles, then I put 4 gals to the oil at changing. Now I have 1,100,000 miles on my truck and she is still going strong! No smoking and it still uses the gal oil a week it always did. Did I mention that I also use Lucas 5th Wheel Lube? I do and I am more than satisfied with its ease of application and smoother trailer movement. Thanks Lucas keep up the good work.