This is take from a post in a land rover forum: _____________________________________________ Well, damn GP, that's about the most coherent thought I've heard from you since you pulled the Jag tail lamps outta your ARB. FWIW, I started an Acetone experiment a couple of months ago on the D2. I'm running between 8-10oz per full tank (24gal), sometimes a little less acetone. Truck specs: 99D2, 88K miles, orig O2 sensors PowerChip STI plug leads Bosch Plat (2) Safari Snorkel 4.11 gears 3" RTE lift 285/75-16 on stock alloys Warn 15K, RTE sliders/bumper, Greg Davis rear bumper, Engle and full pelican are always in the truck. I'm an easy driver with the right foot and rarely exceed 75mph on the hwy. NO ACETONE, country roads, town driving, pre-MAR: 264 miles/19.5 gal = 13.54mpg 292 miles/19.7 gal = 14.82mpg This was around MAR and right about here, I put in new plugs and wires (Still no acetone): 322 miles/20.7 gal = 15.55mpg (about 85 miles here was hwy) 319 miles/19.9 gal = 16.03mpg (about 90% hwy miles here ) WITH ACETONE, 80% hwy / 20% city (Knoxville, TN) 348 miles/20.3 gal = 17.14mpg 369 miles/20.7 gal = 17.83mpg 358 miles/19.7 gal = 18.17mpg I'm driving around 70mph on the hwy and I only use the cruise on the areas up here on 81 where it's flat. This was my second trip to Knoxville. 336 miles on 20.3 gal with a 15knot direct headwind down 81S running 75mph all the way Back last night, last two tanks of the weekend: 311 miles/20.3 gal: ~15.32mpg, 90% city driving, NO Acetone ( I forgot to put it in) 375 miles/21.5 gal: ~17.44mpg, 85% hwy driving, 8oz Acetone, tried to keep it under 75mph. 334 miles/20.3 gal: ~16.5mpg, about 50/50 hwy/city (ran 75-80 on the hwy mostly) _______________________________________________ Has anyone else put acetone in with their gas? It seemed to help this guy and a few others out quite a bit.