I had c320 wagon( same engine as the limited crossfire) that i used reg in because the guy i got it from said he had always used reg. gas, long story short , i only pushed the car once or twice
because if you check,,, a lot of the turbo cars today have two hp setting example, my ford fusion turbo, in the manual says 210 hp on reg and 235 hp on
premium. so that being said the limited can be 205 hp on reg and 225 on premium.some people say with the crossfire you only need the premium gas when you push the peddle to the metal. oh,, the wagon i use nothing but premium in it today and at 110,000 miles it runs great. jim