Introduction To Roth Automotive Science › Forums › Engine › What Fuel Mixtures do Modern cars run? Tagged: engine, fuel-air mixture, lean-burn, rich, SkyActive-X, stoichiometric This topic has 0 replies, 1 voice, and was last updated 5 years, 10 months ago by admin. You must be logged in to reply to this topic. Log In Username: Password: Keep me signed in Log In