Originally Posted by Tuner Boost

We do our crankcase evac mod system for fleets just for fuel economy (have reference to contact for real world verification) alone as they really dont look for extended engine life, etc. as most are leasing the fleets. The average on a ecoboost is 1-3 MPG improvement.

To understand (and this wont work using the average oil catchcan that lets as much oil past as it catches, it can only be a system that catches all, or nearly all the oil without any pull-through occurring) you have to look at how the ECU/PCM controls the ignition timing, fuel trims, etc.

If the engine is not running at optimum advance, the power produced and the economy will suffer. Any oil contamination in the intake air charge (and thus the combustion chamber) will reduce the amount of energy released per explosive event, has a negative effect on the burn pattern, and causes detonation under a load so the knock sensors will detect this and the ECU/PCM will pull ignition timing to prevent damage. This alone is 2-3 MPG on average lost. Eliminate the ingestion (the RX system is available through several supporting vendors here, MAKPerformance, Ecoboostpowerparts, Rodney of SSI, etc.) and you see your fuel economy improve along with it.

That is one sure way. A "economy" tune is also where A/F ratio is optimized for economy as well.

On these fleets we will program RPM limit to 4500, top speed to 75, etc. to reduce employee abuse, etc.

Ask any questions in detail to better understand any of this.

Originally Posted by w0lvez

You can save more fuel if the tank is always full. It may sound stupid but it really does reduce your consumption a lot. The only logical answer I can think of is if the fuel tank is full of liquid fuel the space for vapor. The fuel tank has a vent that allow fuel vapor to escape in order to maintain proper pressure.

Originally Posted by w0lvez

You can save more fuel if the tank is always full. It may sound stupid but it really does reduce your consumption a lot. The only logical answer I can think of is if the fuel tank is full of liquid fuel the space for vapor. The fuel tank has a vent that allow fuel vapor to escape in order to maintain proper pressure.

Originally Posted by Spannerhead

I don't buy this without hard numbers. The fuel vapor gets sucked into the engine and burned via the evaporative emissions control system. If anything the truck should get slightly better mileage with the tank emptier b/c it's not hauling around the weight of the extra fuel.

Even if you make the argument that consistently running with less fuel in the tank means the contaminants (i.e. the "dregs") in the tank will be less diluted by fresh gas, and thus compromise the fuel-air mixture and dirty the injectors, reducing mpg, the fuel filter should take care of all of that... That's about the only hypothesis I can think of that would come close to justifying the theory.

Originally Posted by Krack499

I think he's saying if you fill it all the way the needle stays at full longer so it gets better mileage not realizing that filling it that full is just putting gas in the filler neck so it has to burn that off before it starts reading it on the gauge

Originally Posted by Krack499

I think he's saying if you fill it all the way the needle stays at full longer so it gets better mileage not realizing that filling it that full is just putting gas in the filler neck so it has to burn that off before it starts reading it on the gauge

Originally Posted by Tackle

Getting better mpg than what was shown on the window sticker 10+ years later is quite an achievement. Especially with a stock truck.

Originally Posted by Tackle

This is retarded and I hope that is not what he meant. Miles per gallon. Not determined by how much the needle moves. It's easy math to be spot on.