That one has always been good. Buick uses a low differential gear. The same transmission out of a Pontiac will be more peppy out of the gate but 3 or 4 MPG less on the highway. With mine, the difference between 65 and 75 mph is about 5 mpg.Really? That sounds way high. Hell, I only get around 25 in the 2.0 4cyl Neon.