The work I did on my car earlier this summer has clearly helped my gas mileage. I had been getting around 28 mpg beforehand, but the first full tank afterward I got 34.8 mpg. Quite an increase. And that’s with running the fixed air conditioner sometimes. On the second tank, I’m getting 33.6 mpg, which is still quite an increase.

The brake job is most likely the vast majority of the difference. I could tell there was some extra drag just by feel of accelerating and coasting down hills and what not, but the wheels getting hot enough to smell like burning sometimes was the more concerning sign. Replacing the rusty front calipers and filing the rear pad notches so they could slide really helped.

The exhaust fix probably helped a little bit too. When there’s a hole in the exhaust, I feel it can cause resistance in the flow, depending on its characteristics, and thus add resistance to engine output. It feels smoother accelerating at the pedal. Even if that didn’t help with mileage, it definitely is easier on the ears.