2014 Honda Accord 2.4L 102,000 miles
Drained factory Honda coolant, which is extended life 150,000 miles / 10 years. I keep a log of my mileage and maintenance and average around 35.5 mpg highway. I immediately noticed what seemed to be improved highway mileage with improved acceleration from 80-100. After 800 miles over a 4 week period I have an increase of ~4% or 1.4 mpg. This is driving the same course to and from work as prior to using Amsoil coolant. Another words comparing apples to apples. Being an engine developer from the muscle car days I was fascinated on how this could be. Better thermal efficiency does translate to more horsepower, but usually not that much of a mileage improvement. What I found does explain the result in such a mileage improvement. The answer - the dual cooling fans taking longer to come on and running less once they do. Less electrical draw and engine output needed for the same driving condition. For someone who keeps their vehicles hundreds of thousands of miles, as I do, better heat transfer means less friction resulting in less wear & tear resulting in engine & transmission longevity. Here is some real technology. Whoda thought there could be such a difference in coolants. My hat off to the Amsoil team. It is a real pleasure & surprise to find a product that delivers and isn't just sales verbiage. I am currently road testing their CVT transmission fluid in the same vehicle.