Fuel Mileage booster’s

As far as the ECU is concerned, the absolute best "tune" on a stock engine is the stock tuning -- just ask any Federal judge! (Oh, by the way, I am recognized by the US Federal Court System as a "Fuel Economy Expert". Though it would have been nice to fill out the form and pay the fee, I earned that title the hard way! Thus my username mpgmike.) However, if you improve combustion efficiency, the stock tune is no longer ideal. That's why cam changes, exhaust upgrades, turbos for the love of Pete REQUIRE a re-tune to get the most from them. Fuel economy is no different. Without correcting the ECU's tune, most devices don't stand a chance of improving fuel economy by any noticeable amount. There are quick-fixes that at least get the ECU to give up 15% to 40% with proper hardware. For serious gains, more drastic measures are required.