My R60/6, when running in the worst of shape was around 22 mpg. After new rings and a good carb cleaning I also hit about 30. However with 100 octane low lead aviation fuel, I was easily hitting 40 with an abundant increase in power. Using BMW´s oil in the recomended viscosity seems to help overall performance and economy. Also the entire charging and ignition system is very important to maintain as meticulously as possible. Test it, replace what may be worn, then clean it´s components behind the front cover with non alcohol cleaner as often as needed via visual inspection. Good Luck.