I've got 232,000 miles and recently had a 35.5 mpg tank of gas that was roughly 80% highway. The only engine work that's occurred is a new head gasket, which was only necessary because I pulled the head to chase an oil leak associated with the profile gasket. I lapped the valves and replaced the valve stem seals while the head was off, but I doubt that had much effect on performance. All four cylinders still displayed the original honing. |