1995 LS Sedan, 148XXX miles, 421 header, short intake, 2 1/4 exhaust, punched cat, OTTO muffler (no silencer), No AC, No PS, headlight drilled where intake rests, Nology hotwires, iridium plugs, grounding kit, ACT Prolite Flywheel, 6 wing clutch, 87 octane, 5W-30 Mobil1 Synthetic oil. Combination of highway and stop go, 32 MPG with two runs with other cars in town. When I use my baffler I seem to get a lot worse mileage...funny.