Tires Rotated and Air Filter Washed

mileage = 82296mi

The heat shield for the catalytic converter was hanging down and scraping the road. After jacking up the car, I saw that the heat cover was all bent up and being held on by one bolt. The three other bolts were still there, but the metal had ripped on the corners. Instead of removing the bolt, I just twisted the heat shield until it broke off.

Since I had the car jacked up, I rotated the tires and discovered why the new tires are yielding lower gas mileage. The stock steel wheels and tire weighed about 34 lbs and the new wheels and tires weigh about 43 lbs. I guess a 9 lbs difference per tire/wheel can lower the fuel mileage by 3-4 mpg. So my fuel mileage dropped dramatically after changing the plugs and tires/wheels because both changes introduced a new issue. One of the plug wires broke so that was the main drop in fuel efficiency, but each tire is about 9 lbs heavier. On good weeks, the car can get about 30 mpg and on a long road trip I saw 33 mpg.

While I was doing car maintenance, I washed the air filter with dishwasher soap and a bucket of water.