Nozzles and/or Tune for MPG

To the OP, if you are only going for a few more MPG, just slow down.

When I started modding my Jetta, I did so with the intention of at least keeping the same MPG or better. I have had 3 tanks over 900 miles, and had 10 straight tanks over 800 miles. It is possible, but only if I keep my speed down. Mods and a link to my fuel records in my Sig.

Agreed, your #1 deciding factor is driving habits, then tires, then tuning, then nozzles.

DLC520 probably beat 1019 for mileage by the slightest amount. EGR deletes help a little with highway mileage but will hurt warm up time and pre-operating temp fuel economy as a result.

Won't make your money back on nozzles but the extra power is nice. Michelin touring tires and a stage 1 tune with dynamic EGR will probably net the best mileage.