runs good and doesnt stumble on acceleration, you dont have a vac leak. that is a heavy car. if the plugs look the right color, light brown. you are running as designed. that mileage doesnt surprise me. an sl is about the same weight as my 500sec. the mileage should be about the same in town perhaps a little better on highway since the sl has less frontal area.

tom w

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[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.