DieselDawg

I would like to see that in some literature...All I have seen about octane was it might help in higher heat and heavier load situations...when it comes to the Ecoboost. I have noticed (using my Android and Torque App) that the timing does adjust while driving.

BoostedFx

So by using a higher octane the engine should run smoother under load????? I have noticed sometimes while driving on the interstate at 70mph with the cruise control on my truck will feel as though it has a very very very slight miss fire while going up a steeper grade. The engine goes under load but it doesn't down shift out 6th to 5th. Doesn't happen all the time and its very hard to notice when it does happen. I drive 6 1/2hrs every two weeks Florida to Louisiana / Louisiana to Florida (435 miles one way) to and from work. So I have plenty of time to learn my engines characteristics while driving. So guess what im getting at is should I spending more $$$ on higher 93 octane. Im also starting a thread about why there is soot in the EB exhaust tail pipe.

engineermike

This is all dead-on.

Winter gas is blended with more "light" components that will atomize more readily at cold temperatures. These "light" components are lower Molecular Weights and thus, release less energy when combusted. Combine that with the deeper vacuum gas engines draw at colder air temps, and winter mileage suffers more.

Another common wive's tale is that higher octane produce worse mileage and/or less power when that octane is not needed. This is not true. Resistance to detonate does not reduce the energy released or burn slower once lit. In fact, the opposite can sometimes be true. In some cases, highly refined high octane race gasoline can make more power than pump gas using less timing advance.

Octane rating, btu content, and burn rate are not all the same thing, and can be varied independant of each other.

Something else worth mentioning is that the Mustang 5.0 has two different power ratings from Ford, depending on fuel octane only. This is because the Mustang runs, what most would consider to be, too much compression/timing advance on the base tune. It then uses feedback control on the ignition timing to run on the edge of detonation. [Maximum timing advance before detonation normally does not make maximum power, but on this engine it does.] The truck 5.0 and the EB do not have this same dual power rating. This leads me to believe that if octane made a power difference in the EB, Ford would have given it a dual rating also.

dreuter

iTrader: (1)

I use an app on my iPhone called "pure gas" it showed you where pure gas is available around you.

EBinMT

JoeWee3.5 probably uses premium for a couple reasons,

1) resistance to detonation. This is a high compression, force induction motor and while the programming compensates for this the manual still recommends running premium in severe duty applications such as towing.

2) Premium fuels usually have more detergents as well. most applications this will have no real benefit as regular grade usaully has more than enough detergent, but if you have seen the black soot in the EB tailpipe this may be a good investment.

personally I prefer a mid grade from my local Exxon. I used to deliver Exxon fuels and know that station has only a Regular and Premium tank. Their Mid grade is the same price as the regular and is a 50/50 blend of premium and regular. so I am getting a little better octane and more detergent for the same price.

DieselDawg

Actually there are "Top Tier" fuel providers that supply fuel with higher than minimum EPA standards fo detergents in fuels...those Top Tiers suppliers put the same detergent formulation in every grade (for the most part).

As for the "black soot", I think it is more from the fact that the Ecoboost does not have an EGR (mechanical) and uses the engines own characteristics :

This EcoBoost truck engine also features twin independent variable camshaft timing, or Ti-VCT, to help save fuel. Ti-VCT provides extremely precise variable – yet independent – control of timing for intake and exhaust valves. Ti-VCT also reduces emissions, especially in situations when the throttle is partially open.
***http://media.ford.com/article_displa...le_id=33260***

This means it will run a bit rich to reduce NOx for emissions

Georgiaboy5.0L

All the post here have a good point and most are very good information.......but after 12000 miles logged on my 2011 5.0L
it's worth the extra cost for higher octane fuel for me....93 octane gets me 2 more miles per gallon average than 87 octane.............5 more bucks a tank full is not that big a deal....for better mpg and performance.

Joewee3.5

I use 93 oct for a couple reasons. One is to insure I am getting every ounce of power there is available. If by some chance I pick up 10hp over 87 oct, great. If not, oh well, my mind is at ease knowing 93 is in the tank. Simple as that. I have the money for the extra octane so why leave anything on the table. the other was mentioned before and that is the possibility of more detergents for cleaner burning. I have read that exxon 93 oct has more cleaning detergents than other octanes and other 93 oct brands. On a side note, I can no longer find non-ethanol fuel anywhere in my area.

Theocoog

Thanks. FWIW, I haven't seen straight gas in years. Everything in my part of the country is E10, which sucks.

TwinTurbo JC

Thanks for the information on this site. I found out the closest non ethanol gas is 77 miles from me. Looks like it would be very handy on long trips to plan your fuel stops and be able to take advantage of the benefits!