davo32683

iTrader: (5)

My 2011 4x4 SCREW 6.5' gets around 16 avg in my mixed commute. Our entire fleet is roughly the same.

Tuner Boost

When we log these, we see knock retard quite often when 87 is used, most of that goes away on 93 so the ECU is not pulling timing advance, so that results in better fuel economy. Thats what your seeing. The cost is probably a wash, but the engine will like you for it.

Also, stop the oil/gunk ingestion and most all the timing pull disappears for even better. You want only air & fuel in the combustion chamber.

biff420

Its automatic, don't think there is really anything you can do to make it lock. You can tell its locked in when you are cruising and hit a smaller hill. Watch the RPM gauge, it won't move a mm even though your speed stays constant. This is because the torque converter is locked in and is multiplying the power from the engine without the engine revving up. Without the torque converter, the transmission would drop a gear and the engine would rev up and increase power in order to maintain constant speed with the increased load up the hill.

I'm no expert, but this is my understanding of how these things work and how these trucks are able to maintain such low RPMs and still produce loads of torque even with twin turbos.

The only thing I've found that helps with making sure you're locked in is to use M mode on the shifter and get to the highest gear possible while cruising. That is when you aren't going 55+ which will automatically put you in 6th.

Bigfoot02

did 18-19 running 70-73
did 21 running 60-63

packplantpath

I've done testing with 87,89,& 93 octane.

Logging knock retard there is no difference with boost under 6psi. Over that the higher octane helps some. But regardless of octane my kr never ranges outside +-1 unloaded and is the same with all octane levels in normal driving. When towing or at heavy acceleration or near wot, this does not apply and 93 is helpful all around.

The only time 93 octane got me better mpg unloaded was when it was ethanol free. That was good for 2-3 mpg. Unfortunately it costs way too much to be worthwhile.

Tuner Boost

Yes, alcohol has to be ingested in greater amounts than gasoline to maintain the proper A/F ratio so usually will be less MPG.

gillysmi

one thing I have noticed with the truck in my sig is head wind. my mileage is crap. but if I can get a tail wind I have hit 16 mpg at 70mph. a head wind of 5mph or more I drop to 12.5 really fast.


does the headwind effect a turbo engine more than a NA engine??

cartmanea

No, but it affects a small engine more than a large engine. With only 3.5L of displacement, the Ecoboost needs boost and lots of fuel to produce power, which kills the efficiency.