2 Months, 13 fill ups & 4,000 miles later I've come to the conclusion that Super unleaded (93) has no fuel saving advantages over regular (87) gasoline. 27.3 on regular vs 27.2 with super calculated manually.This is with 80% easy suburb driving. Computer was always ~1mpg optimistic, but consistant.

 

Most of time I see 93 Octane with ethanol to get the number higher. It seems ethanol hits my mpgs by 1-3 during the winter months when we have to use it in the city limits. If 91 Octane is ethanol free, that might have been a better test comparing it to 87 Octane.

 

you do know that you contaminated your 87 results!?

I'm betting the little 93 octane that was in the tank upped the 87 a little.

do 3 tanks of 97. then average the results.

do 3 tanks of 87, then average your results.

compare the two averages.


It takes time for the ECU to adjust.
so, your experiment was skewed in your favor.

 

Huh?

 

Y'all never done science experiments?!

 

I have the 2013 more than 2 years now. I filled up premium first year then regular until now. My conclusion overall about 1mpg gain from 93 octane. But it may be due to more road trips during my first year. Maybe just me that I felt VCM was kick in more frequently with premium So if I plan for road trip I'll fill up premium.

 

You're probably right; but I'm not aware of ethanol free gasoline in the West Houston area (or anywhere) that's readily available.
Ethanol-free gas stations in the U.S. and Canada
This is an interesting tool though.

 

Wow those are some nice numbers! I am lucky to hit 24 and average about 23.5 most of the time. I do about 70% freeway driving 30% city roads.. though with our traffic.. and a lot of our freeways are constantly up hill down hill....

 

Houston is completly flat & easy 35mph residential roads primarily. Besides, my wife says I drive like I' 70.