I used Bestline’s Fuel Conditioner and Catalyst when I needed to fill up on gas and I took Shadow out on the highway to work it in. In about a week I noticed she picked up a little bit quicker and my mileage got slightly better which definitely helps with driving a V8! After that when the time came for an oil change I used Bestline’s Engine Treatment along with a higher quality oil and I plan to stick with the Engine Treatment with every oil change from now on. She idles smoother and it feels like she got a few years back along with some power and I have to thank CarSponsors.com for introducing me to an incredible product and company!