[adamjwilson]

From what I read, E50 is not available at any pump. You need to find E85, test the actual ethanol content then mix it with your gasoline of choice to get it to E50... so can someone educate me on how to get quality E50, or is this too much of a PITA? I assume the flex fuel kit for E85 will handle E50 or does E50 need to be tuned in?

[SATINSTEEL1LE]

When people say e30, e40, e50, e60 and so on, thats them blending 91/93 with e85 to reach those alcohol levels.

There isnt e50 at any pump or vendor. You will need to mix up 93 with small amounts of e85 to reach those values. I use an app called e85cal. You can use other apps or you can get a flex fuel sensor installed with a gauge and see what the actual content is as you add e to gas.

[arpad_m]

^^^

If you don't want to invest in a gauge but you need to mix, you can use a few tanks of 93 to "flush out" E85, then next time start your approximate calculation from E10, which represents the E content of 93 octane gas in most places.

[JimGnitecki]

This is an interesting thread. Our local gasoline stations offer only 87, 89, and 91 octane fuel. Every pump offers your choice of all 3 octane levels. There is a label on the pump that states that there "may be' up to 10% ethanol in the fuel.

So, what does all the above actually tell me about the gasoline I am buying?

For example, is the undergorund tank 100% gasoline, and is the octane rating solely dependent upon how much ethanol is mixed into that gasoline by the pump selection I make?

Is 87 octane fuel 100% gasoline?

Is the 10% ethanol level achieved only when I select 91 octane?

Does my LT1 with its Magnuson 2650 "know" how much ethanol is in the 91 octane fuel I am filling with?

Or does the ECU merely monitor for knock and back off timing until there is no knock?

Is there an online guide somewhere on how to blend ethanol into 91 octane gasoline to achieve a certain percent ethanol mix?

I'm asking these questions because fuel mixing is all new to me. I know nothing about it.

Jim G

[SATINSTEEL1LE]

Originally Posted by JimGnitecki

This is an interesting thread. Our local gasoline stations offer only 87, 89, and 91 octane fuel. Every pump offers your choice of all 3 octane levels. There is a label on the pump that states that there "may be' up to 10% ethanol in the fuel.

So, what does all the above actually tell me about the gasoline I am buying?

For example, is the undergorund tank 100% gasoline, and is the octane rating solely dependent upon how much ethanol is mixed into that gasoline by the pump selection I make?

Is 87 octane fuel 100% gasoline?

Is the 10% ethanol level achieved only when I select 91 octane?

Does my LT1 with its Magnuson 2650 "know" how much ethanol is in the 91 octane fuel I am filling with?

Or does the ECU merely monitor for knock and back off timing until there is no knock?

Is there an online guide somewhere on how to blend ethanol into 91 octane gasoline to achieve a certain percent ethanol mix?

I'm asking these questions because fuel mixing is all new to me. I know nothing about it.

Jim G

In all honesty I'd call your tuner and ask all those questions. They know your setup and what it looked like fuel system wise when they logged it/tuned it. If you are on the edge of your stock fuel system, you will be lucky to be able to run e30.

But the general answer to your question about the gas, most modern 87/89/91/93 is all e10. Meaning no matter the octane, it still has 10% ethanol added. So you are always going to be starting at e10. Then if you use that calculator app I posted the screen shot, you could theoretically calculate a blend from there. The only other thing you'd need to know is if the e85 coming out of your local pump is really 85% E. You'd need an E85 tester to check that. Test the E and see where it is. My local station is almost always e80. Then You can calculate how much of the "e85" you need to add to whatever you have in your tank or what you want to fill your tank to in order to get to e30/e40/e50 and so on.

As for the car "knowing". Its not going to know anything unless you get that flex fuel sensor installed. Then once you have that the car can actually see the e blend and raise or lower timing accordingly. Keep in mind that functionality needs to be enabled by your tuner and they would have to tune your car again for e30/40/50 or whatever your fuel system can safely support.

Like I said, call your tuner. They are the best person to guide you into using an e blend. With our cars LT1/4 cars, its dangerous to use too much E until you get the fuel system to support it. These are not like Hellcats or Mustangs where you can change the injectors and you are good to run full e.

[arpad_m]

Originally Posted by SATINSTEEL1LE

In all honesty I'd call your tuner and ask all those questions. They know your setup and what it looked like fuel system wise when they logged it/tuned it. If you are on the edge of your stock fuel system, you will be lucky to be able to run e30.

But the general answer to your question about the gas, most modern 87/89/91/93 is all e10. Meaning no matter the octane, it still has 10% ethanol added. So you are always going to be starting at e10. Then if you use that calculator app I posted the screen shot, you could theoretically calculate a blend from there. The only other thing you'd need to know is if the e85 coming out of your local pump is really 85% E. You'd need an E85 tester to check that. Test the E and see where it is. My local station is almost always e80. Then You can calculate how much of the "e85" you need to add to whatever you have in your tank or what you want to fill your tank to in order to get to e30/e40/e50 and so on.

As for the car "knowing". Its not going to know anything unless you get that flex fuel sensor installed. Then once you have that the car can actually see the e blend and raise or lower timing accordingly. Keep in mind that functionality needs to be enabled by your tuner and they would have to tune your car again for e30/40/50 or whatever your fuel system can safely support.

Like I said, call your tuner. They are the best person to guide you into using an e blend. With our cars LT1/4 cars, its dangerous to use too much E until you get the fuel system to support it. These are not like Hellcats or Mustangs where you can change the injectors and you are good to run full e.

All agreed, just a clarification to your point "they would have to tune your car again for e30/40/50 or whatever your fuel system can safely support" for OP's sake: this doesn't mean one needs a tune for E30, another for E40 and yet another one for E50 etc., the tune can be universal and support everything from E10 to E85.

However, one must still be aware of their fuel system limit, let's call it Exx, and make sure they mix whatever E they get at the pump or from a drum down to Exx or less. Or at least stay away from WOT until the E content is confirmed to be at or below xx ("when in doubt, don't go WOT", sorry, I know it sounds really bad).

Nothing like a real gauge or OBD-II/scan tool that displays actual E content, though.

[JimGnitecki]

Thank-you both. So, again forgive the newbie questions:

1. If you do not install a flex fuel sensor, your car does not benefit at all from using an ethanol blend?

2. If you have a flexfuel sensor, and do use an ethanol blend, does your fuel system have to provide MORE fuel than it did on straight gasoline (or the 10% ethanol now apparently dispensed by most gas pumps) in order to make the same power as it did on straight gasoline? (I'm asking this because it sounds like ethanol COOLS combustion but REDUCES power per gallon of blended fuel used. is that correct?)

Jim G

[arpad_m]

Originally Posted by JimGnitecki

Thank-you both. So, again forgive the newbie questions:

1. If you do not install a flex fuel sensor, your car does not benefit at all from using an ethanol blend?

2. If you have a flexfuel sensor, and do use an ethanol blend, does your fuel system have to provide MORE fuel than it did on straight gasoline (or the 10% ethanol now apparently dispensed by most gas pumps) in order to make the same power as it did on straight gasoline? (I'm asking this because it sounds like ethanol COOLS combustion but REDUCES power per gallon of blended fuel used. is that correct?)

Jim G

1. Correct. The sensor will inform the ECM about actual alcohol percentage in the fuel, and will make adjustments on the fly if the proper tune is written into the car.

Without the sensor, the ECM has no information and has to resort to assumptions, using defaults regardless of the fuel in the car, which means you might destroy your engine if you pump E85 without the tune. All in all, you need a flex fuel sensor and a tune.

2. Also correct. This is the reason why mixing down is a necessity for some (like me with a relatively strong FI build and an LT4 fuel system with just a voltage booster) but not for others, their fuel system has enough overhead to supply the extra 25% or so fuel when E85 is being used. The lower the E content, the less extra fuel system capacity is required.

[JimGnitecki]

Originally Posted by arpad_m

1. Correct. The sensor will inform the ECM about actual alcohol percentage in the fuel, and will make adjustments on the fly if the proper tune is written into the car.

Without the sensor, the ECM has no information and has to resort to assumptions, using defaults regardless of the fuel in the car, which means you might destroy your engine if you pump E85 without the tune. All in all, you need a flex fuel sensor and a tune.

2. Also correct. This is the reason why mixing down is a necessity for some (like me with a relatively strong FI build and an LT4 fuel system with just a voltage booster) but not for others, their fuel system has enough overhead to supply the extra 25% or so fuel when E85 is being used. The lower the E content, the less extra fuel system capacity is required.

Thank-you, Arpad!

Jim G

[KingLT1]

Mix it 50/50 (5 gal pump 93/ 5 gal pump E85) and you will be close to E50.

[arpad_m]

What King said, adding E85 and 93 in equal amounts will result in E48, plus here is a nice mixing chart for you if you don't want to install (yet) an(other) app. I put a red border around full Camaro tank blend ratios in the chart.

[Schlok]

Originally Posted by arpad_m

What King said, adding E85 and 93 in equal amounts will result in E48, plus here is a nice mixing chart for you if you don't want to install (yet) an(other) app. I put a red border around full Camaro tank blend ratios in the chart.

Wow, that's a nice table, good work!

[wnta1ss]

Need to test the actual ethanol content of your E85 to get an accurate mix, because they vary from pump to pump, and also can vary with time of year. I have bought E85 at various places, and the strongest pumps have been 79~80 percent, but also have seen it pumped as weak as 53 percent.

[laynlo15]

Originally Posted by wnta1ss

Need to test the actual ethanol content of your E85 to get an accurate mix, because they vary from pump to pump, and also can vary with time of year. I have bought E85 at various places, and the strongest pumps have been 79~80 percent, but also have seen it pumped as weak as 53 percent.

I agree, my stations never have over E70 and most of the time it's about 65 which is good for me, no mixing required. If you were to have stations like ours you'd be way below E50 with the equal amount of 93. So for sure you should be a tester. .