new gas

It shouldn't, it actually should get lower MPG.

But since the difference from E10 is only about 1.6%, you'd need quite strictly controlled conditions to accurately detect and measure it. Other common variables typically create larger differences and tank-to-tank variations than that, making it very difficult the accurately characterize the true MPG difference.

 

That's what I've experienced with previous cars - my 2006 KIA RIO and FORD FOCUS (and others) of the same era did consistently worse on E10.

But I've filled Samantha a few times in a row with E10 and she's happy with it and has at least equalled and in some cases, improved on ULP. I guess the EV component of driving isn't concerned about what fuel is used .

The Renewable Fuels Association, in a report 2 yrs ago said "All hybrid vehicles (when operating on engine power for PEVs) and ‘strong’ HEVs especially operate more frequently at the engine’s peak efficiency region, and for this reason would be able to capitalize on high octane mid-level ethanol blends’ capability for further improving the efficiency and fuel economy and reducing GHG emissions. Hybrids that utilize Atkinson cycle engines are also subject to the potential gains from high-octane ethanol blends" - so maybe there is something in it?

 

I saw a very noticeable drop in MPG which is what I expected due to the additional ethanol.

 

We've had E15 here for quite awhile now. When I first switched I noticed a significant up & down swing on my first few tanks. (Click on my fuelly) But it has since stabilized. We're in the cold weather months now so my overall MPG's are way down, but I didn't really notice much of a change. Not sure of why I seen the huge swings when I initially switched, but other than that... I'm good with it and I run it in every fill-up.

[edit} the big "swings" were back in late Aug early Sep. So if you click my fuelly you'll have to then click "show all fuel-ups"

 

He may be seeing the same big increase in MPG's, I initially seen - then it swung down, then back up yet again before stabilizing.

 

Lot's of the anayltical qualities of gasoline are invisible to the user. So we don't know energy content and other formulation variables. So it is conceivable there are variations, at the pump, day to day etc, so maybe one day E15 has more MPG but in general we would expect it has lower MPG.

 

Checking the Owner's Manuals, 2010:


And 2016:

 

This guy talks about properies of gasollne being "invisible" to the user which is the point I always try to make, so I stole his schtick.
The dirty little secrets of cheap gasoline - Video - Roadshow

 

His explanation of direct injection was helpful. My son and brother (both master techs) complain about working on these vehicles all the time. Major work required around 40-50k because they get all gunked up.