My 2001 Buick LeSabre V6 3800 Series consistently got 26 MPG. At 150,000 miles I had the original spark plugs replaced. I wish I had not. The car still drives great but my mileage dropped to 20 MPG. Can you tell me what factory plugs were in it and if it would help to replace them with what was originally in the car?
Jul 19, 2007 at 9:49 PM