I have a 2007 Subaru Forrester XT Sport. It has a turbocharger and "requires" premium gas (93). What would happen if i put regular in (87)? My manual says very bad things. However, i read online in a forum that since the late 1980s, there has been a law requiring automakers to make all their cars run on regular gas. Allegedly, if i put 87 in, not only will i be saving money on gas, but i will get better gas mileage due to the turbocharger being shut off (when the sensors detect 87 instead of 93). is this claim true or bogus. it would be GREAT to save some money on gas, even if it comes at the expense of performance.