Just thought i would pass along that since my last post on Sept 17th that i have gained 1 mpg so far in my 2000 300M. After two tankfulls, the first gaining 4 tenths of a gallon to 24.7 till today at fill up with 25.3 mpg, a 1 mpg increase from my earlier average. Just for the record, i don't baby this car. I drive anywhere from 65 to 85 mph and higher on the highway when needed if i'm running late for work. My driving is light city, mostly country with some highway. The 300M has a nice 3.5 liter motor with a compression ratio of 9.9 to 1 which i have faithfully supplied with 91 to 93 octane because of a noticable reduction in mileage if run on 87 octane donkey drool. When gas prices went sharply higher, i started carefully using the 87 octane without any complaints from the motor at light to moderate throttle. With acetone i can run the 87 octane and so far i have verified the highest averag mpg that have ever seen even when using 91 to 93 octane. I'm driving to Pittsburg tomorrow so i will get to use a full tank at highway speeds of 65 to 80 mph and will let everyone know what happens. 26 to 27 mpg has been the norm for this trip in the past. 28 mpg without the airconditioner at 75 miles per hour average.
One more experience has been what feels to be more responsivness when rolling the throttle down just off of the cruise position. This could be a sighn that the computer is giving full advance that was taken away because of the use of 87 octane to cut back on fuel costs. Gas stations around here are charging 30 cents a gallon more for high test which would be an extra $4.50 for a 15 gallon fill up. Acetone costs are about 60 to 70 cents per tank based on a quart purchased at Walmart around $5.00. If things continue to hold true with further testing, acetone's stated benefits of fuel vapourization could easily exceed what had been seen by the use of expensive hightest fuel.... More to come.