I have 2000 Toyota Echo 180K that was getting just little over 30mpg and now I get 45mpg 80% city 20% Hiway with treated motor, 5sp trans, steering, TB mod, magnets and NGK Ruthenium HX with a 20% bigger gap. I get 496 miles per tank.

Since I been using Tribo-MAX Fuel+ on my 00 Toyota Echo (TB mod, motor, 5sp trans and power steering treatment). I gain 70 miles per tank 80% city and 20% hi-way with Fuel+. It didn't happen over night it took about 16 tanks full. I believe and this is just a prediction an extra 150 -170 miles per tank on the hi-way. I'm just happy that the stupid engine control unit (ECU) is willing to accept the change. Like I said before the engine control unit (ECU) is your Biggest Enemy when it comes to MPG.

I forgot to mention about AC additive results on my 2015 Yaris it run 10 degree colder, 2005 Sienna 14 degree colder and 2006 Prius 6 degree colder and 1-2 mpg gain.