Best / Recommended Octane

[Rakimb17]

I have over 9000 miles on e-30 getting 13 to 14mpg with the duratracs. it is 10 cents cheaper and I had it 125 in under 2 miles easy js

I ran e85 in my 87 Grand National, e46 M3 and had a buddy run it in his EVO.
All of the cars were tuned for it with bigger fuel pumps and injectors and made sick power. Didn't really care about mileage because it was about a dollar cheaper than premium and 6 bucks a gallon cheaper than race gas.

I bet you supercharged guys could have some fun tuning with e85. Never played with e30 though.

 

[blockdoc]

I noticed Amsoil recommends a shorter oil change interval when using e85. Why is that?

 

[ISFast]

I noticed Amsoil recommends a shorter oil change interval when using e85. Why is that?

You have to burn more fuel to make the same power which goes back to dirtier oil.

 

[genus727]

How'd you get a 6.4L gas burner or is it a 6.4L Diesel? :********:

Typo corrected. Thanks.

 

[Wilson]

you don't need the bigger fuel pumps for the e-30 still great power imo.

 

[Rakimb17]

You have to burn more fuel to make the same power which goes back to dirtier oil.

Something about the e-85 breaking down your oil faster. Same thing with alky injection. Anybody have a stock e-85 car to chime in on this?

 

[ISFast]

Something about the e-85 breaking down your oil faster. Same thing with alky injection. Anybody have a stock e-85 car to chime in on this?

Your talking about the acidic properties that both ethanol and methanol display. But that goes into other stuff like fuel having to mix with the oil and if there is water containment. Which we know both are hydrophilic. Also, if your not getting a complete burn from the fuel which most modern OEM stuff should be fine. Unless your Greg....

I was referring to the fact you have to burn more fuel to get to the same place with the same driving conditions. Yes ethanol has a higher octane rating but the energy density of ethanol isn't there compared to 100% gasoline which equals more burnt fuel which should make the oil dirtier. e10 is about 3% difference and so on up to like e85 that is around 25% drop in efficiency.

Just a quick search around on the interweb and sounds like its a lot of CYA incase the "optimal" ethanol isn't 100% spot on to specs.

 

[HoldenTX]

It looks like a bunch of you are running 91+ octane. Is everyone who is doing this have an aftermarket tune? Why would you be running an octane greater than 87 without the aftermarket tune? The engine compression is low enough and the engine timing is set up to avoid knocking at 87 octane. I run 87 all day long without knocking. As far as I know, the factory 6.2L engine isn't equipped with an octane sensor, which would change timing with a higher octane. My thought is that using a higher octane gas is a waste of money unless you are doing so for the additives put in higher octane gas (i.e. Techron).

Hi guys - I've been looking around (maybe not hard enough) for the answer to this question....what does Ford say about the 6.2L and octane levels?
My current car (GM) will run fine on 87, but GM recommends 93 for about 10 extra HP.
What does the raptor manual say about fuel?

 

[ISFast]

Same as GM just the extra hp but it will run fine on 87. Only time i'm not on 87 is when offroading and then its a maybe.

 

[SERG09]

Hi guys - I've been looking around (maybe not hard enough) for the answer to this question....what does Ford say about the 6.2L and octane levels?
My current car (GM) will run fine on 87, but GM recommends 93 for about 10 extra HP.
What does the raptor manual say about fuel?

From the 2011 manual:
"Octane Recommendations

Your vehicle is designed to use "Regular" unleaded gasoline with a pump (R+M)/2 octane rating of 87. In high altitude areas, we do not recommend the use of any "Regular" fuel with an octane rating below 87.

Horsepower (SAE net):
401 hp @ 5500 rpm on 87 octane
411 hp @ 5500 rpm on 91 octane

Torque:
434 lb-ft @ 4500 rpm on 87 octane
434 lb-ft @ 4500 rpm on 91 octane