My MFA is giving a very low MPG, prob due to a leak in the vacuum hose feeding it, that i havn't nothered to fix yet, but using the pen and paper method I average about 32mpg, 300+ miles to a tank with a variety of driving, and roads, speeds etc.
Car pulls smoother and harder using Optimax, no doubt.
Kust fitted a K&N, and not sure on consumption yet, doubt there will be much difference, but sounds a little better.