August 17, 2018
August 17, 2018


Royal Purple® Max-Clean® is a state-of-the-art high performance fuel system cleaner that maximizes the performance of your fuel system. Max-Clean restores fuel economy by deeply penetrating deposits and cleaning injectors, carburetors, intake valves and combustion chambers.

The illustration below shows the before and after effects of switching to Max Clean.

Royal Purple Max-Clean is EPA / CARB Compliant. Recommended for use in gasoline and diesel engines and can be used with all ethanol blends or biofuel. Max-Clean can be used in both 4-cycle & 2-cycle engines and will not harm vehicle emissions equipment.


Multiple product fleet tests were conducted on various makes and models of vehicles. Royal Purple found that after as little as one treatment Max-Clean can:

  • Restore fuel economy an average of 3.2%
  • Restore horsepower an average of 2.6%
  • Reduce hydrocarbon, NOx and CO emissions (on average 12%, 13% and 18% respectively)
  • Prevent rough idle, hesitation and stalling
  • Prevent premature spark plug fouling
  • Reduce deposit-related engine knocking and pinging

Royal Purple Max-Clean also stabilizes fuel during low-use and storage periods, preventing varnishing of fuel.


Pour entire contents of bottle into nearly empty tank immediately before refueling, then install fuel on top of additive. One (1) can treats up to 20 gallons. For tank sizes outside of this range, use one (1) ounce per gallon. In two-cycle engines, use one (1) ounce per gallon.


Max-Clean should be used every 10,000 miles or annually, whichever comes first.

Available Sizes

Available SizesPart NumberItem Number
6 x 20-Oz. Case11723300990175256
20-Oz. Bottle11722