Hi,
I'm new to this kind of tuning.
I've already tuned the spark tables to give more advance to use 98RON, I adjusted and recalibrated the MAF tables based on the advice here and now, after I have some power gain I would like to bring the mpg up.

How the best to do that?
What can I do the fuel side to make the car more economic. The spark advance did some good things.
I was on 11.8 mpg and now I'm on 15 mpg but would like to get close to 20 mpg.

Any ideas?

Thanks.