Gas tank and mpg questions, new to me used 2006, bear with me.

[locovaca]

systems DO adjust for e10

using e10 you'll see worse milage than 100% gasoline, and e85 is even worse.

ethanol needs to run richer to be stoichometric.

driving habits have the largest impact on fuel milage. and the comment about 3k rpms changing to open loop.. im pretty sure its engine load that determines when it switches to open loop because the computer switches to a rich mixture under load to provide power

more pedal=more engine load=more fuel

most i've even gotten out of my ranger was 30mpg going 50mph the whole way and babying the throttle, never been able to do it again.

i average about 20-25mpg now i drive like an old man through hilly/curvy terrain everyday

No system adjusts for E10. Period. Feel free to prove me wrong with the sensor/system on any car which does. The system you are thinking of is the right foot.

Ethanol contains 2/3 of the energy content of regular gas. That means E10 contains (theoretically) 97% of the energy content of regular unleaded. That 3% loss of energy content is not noticeable if you drive normally (lots of highway cruising and calm, controlled acceleration from a stop, etc.)

Like I said, I don't drive like a race car driver, and I see next to no difference between E10 and regular unleaded.

 

[BRUTUS_T_HOG]

i never notice a difference either..

maybe im not following what you're talking about when you say "adjust"

im thinking about the computer switching between rich and lean fuel mixture to average out 14.7:1, and to keep the cat hot.

what are you talking about?

 

[Beanmachine7000]

systems DO adjust for e10

using e10 you'll see worse milage than 100% gasoline, and e85 is even worse.

ethanol needs to run richer to be stoichometric.

driving habits have the largest impact on fuel milage. and the comment about 3k rpms changing to open loop.. im pretty sure its engine load that determines when it switches to open loop because the computer switches to a rich mixture under load to provide power

more pedal=more engine load=more fuel

most i've even gotten out of my ranger was 30mpg going 50mph the whole way and babying the throttle, never been able to do it again.

i average about 20-25mpg now i drive like an old man through hilly/curvy terrain everyday

Yea, ethanol isn't compensated for, ever... Open loop is only used during the first moments of start-up and WOT...

 

[BRUTUS_T_HOG]

what do you mean by COMPENSATE? you mean by richening the fuel mixture to reach stoichemetric.

im not talking about open loop, im talking about CLOSED loop

open loop fuel mixture will be the same for all fuels at idle, and the same at WOT, assuming its not a flex fuel vehicle that senses when it has e85 in the tank.

CLOSED loop operation WILL compensate for E10 and TRY to compensate for E85- by altering fuel injector pulse width to inject more fuel. the fuel mixture WILL change from rich to lean to AVERAGE 450 millivolts on the O2 sensor(s)

450mv will be a different fuel to air ratio between fuels BUT the computer's goal is to average 450mv no matter what fuel is in it.

now i don't know what you're talking about or why you're trying to tell me this is not true

 

[dla]

So ethanol results in more Oxygen. The O2 sensor detects it, the computer says "mixture too lean" and hold the injectors open a bit more. The end result is lower mpg. The problem isn't the energy content of Ethanol, it is the increased Oxygen detected by the O2 sensor.

Ethanol is a oxygenator, (that's why it was originally added - to replace MTBE), it has the side effect of causing a richer mixture, and lower fuel economy. If the Ford control system had an ethanol sensor, it could achieve fuel economy with E10 as good as with regular gas. But Ford is cheap and E10 is a giant ripoff.

 

[BRUTUS_T_HOG]

ethanol requires a richer mixture= less fuel economy.

lets take e85 because it would be the most noticeable.

if you were to burn e85 at 14.7:1 and e10 at 14.7:1 and 100% gasoline at 14.7:1 in OPEN LOOP

the o2 sensor would read lean= <450mv for e85, closer to 450mv with e10, and 450mv +/- for gasoline.

now once the fuel system enters CLOSED LOOP the computer would ADJUST for each fuel by greatly richening the mixture for e85 but probably not being able to supply enough fuel at higher rpms. and it would be richer for e10 than gasoline.

450mv on the o2 sensor is NOT the same fuel mixture for e85, e10, and gasoline.

the o2 sensor senses combustibles and not oxygen (confusing i know), but the leaner your mixture the less combustibles you have left after ignition=less voltage, the richer your mixure it will have more combustibles left over=higher voltage.

the computer will compensate for ANY combustibles. i have done this many times testing o2 sensors while watching the voltage on a lab scope. engine running on e10 and you supply propane to the intake stream and watch to make sure the o2 sensor REACTS by showing a higher voltage.. but ALSO by watching your short term FUEL TRIM to see that it reduces fuel from the injectors to COMPENSATE. it had no way of sensing what fuel it was burning, but it sensed that there was excess combustibles and compensated. now remove the propane and the fuel trim will come back up to compensate. i still don't know where you guys are getting your information. PLEASE explain your side.

 

[locovaca]

ethanol requires a richer mixture= less fuel economy.

lets take e85 because it would be the most noticeable.

if you were to burn e85 at 14.7:1 and e10 at 14.7:1 and 100% gasoline at 14.7:1 in OPEN LOOP

the o2 sensor would read lean= <450mv for e85, closer to 450mv with e10, and 450mv +/- for gasoline.

now once the fuel system enters CLOSED LOOP the computer would ADJUST for each fuel by greatly richening the mixture for e85 but probably not being able to supply enough fuel at higher rpms. and it would be richer for e10 than gasoline.

450mv on the o2 sensor is NOT the same fuel mixture for e85, e10, and gasoline.

the o2 sensor senses combustibles and not oxygen (confusing i know), but the leaner your mixture the less combustibles you have left after ignition=less voltage, the richer your mixure it will have more combustibles left over=higher voltage.

the computer will compensate for ANY combustibles. i have done this many times testing o2 sensors while watching the voltage on a lab scope. engine running on e10 and you supply propane to the intake stream and watch to make sure the o2 sensor REACTS by showing a higher voltage.. but ALSO by watching your short term FUEL TRIM to see that it reduces fuel from the injectors to COMPENSATE. it had no way of sensing what fuel it was burning, but it sensed that there was excess combustibles and compensated. now remove the propane and the fuel trim will come back up to compensate. i still don't know where you guys are getting your information. PLEASE explain your side.

You say potato, I say potato...

E10 is within the acceptable limits of regular gasoline. If it wasn't, it wouldn't run on regular engines without throwing a CEL. The engine doesn't know it's E10 or just some cheap regular unleaded. There is no sensor like on E85 engines to detect and adjust timing/etc. for E10 vs regular unleaded.

The engine is doing what you're describing regardless of it's E10 or regular gas. There are differences between regular gas blends anyway, with winter and summer blends. The engine sensors cause adjustments to be made for those as well.

So by that definition, yes, the engine is making adjustments for E10, but it's not because it's E10.

 

[BRUTUS_T_HOG]

what you're saying is the computer won't compensate for a fuel other than 100% gasoline, this is totally false just get over it

if gasoline and e10 blends were consistant and the vehicle was working flawlessly. yes it would compensate ever so slightly for e10, e10 has a stoich ratio of about 14:1 compared to 14.7:1 of gasoline. you won't notice a difference because most systems are able to provide the extra fuel.

it will compensate or try to compensate for any fuel. thats the end of it.

i was saying that the computer doesn't have to sense what fuel it is running, it senses the condition caused by that fuel when it tries to run a mixture for gasoline and finds that it is running lean because it is actually running on e10, it richens the mixture to average 450mv of the o2

"So by that definition, yes, the engine is making adjustments for E10, but it's not because it's E10."- its because its e10 all the way, it doesn't need to sense what the fuel blend is, it compensates because it senses the air/fuel ratio is not correct for what is being burned.

im done. i think i've explained all i can.

you guys never explained to me why it doesn't compensate but its ok. im just curious where you learned this information

 

[BRUTUS_T_HOG]

wait i skipped over a paragraph

"There are differences between regular gas blends anyway, with winter and summer blends. The engine sensors cause adjustments to be made for those as well." - im sorry but you just admitted that it compensates for different fuel blends

 

[dla]

the o2 sensor senses combustibles and not oxygen (confusing i know), but

The Oxygen sensor reacts to Oxygen and nothing else. A system without an ethanol sensor will run richer and deliver lower mpg precisely because there will be more Oxygen in the exhaust stream.

Everything you said is correct except for the sensor part. We are not disagreeing on why E10 delivers less gas mileage.

My beef is with the rationale for E10 in the 1st place. Why do newer cars need oxygenated fuel? Older carbureted cars yes, but how many of them are still on the road? E10 is ripoff, and Ford is cheap.

 

[locovaca]

wait i skipped over a paragraph

"There are differences between regular gas blends anyway, with winter and summer blends. The engine sensors cause adjustments to be made for those as well." - im sorry but you just admitted that it compensates for different fuel blends

Yes, EFI sensors account for variations of fuel octane, quality, etc. None of that is exclusive to E10. Your assertion is that the engine is changing because it's running E10. My point is that it does nothing specifically because it is E10, it is just making changes as it does for any fuel.

However, for E85, the engine DOES detect the ethanol content in the fuel and adjust timing specially for that. But for E10 it does nothing out of the ordinary.

 

[BRUTUS_T_HOG]

The Oxygen sensor reacts to Oxygen and nothing else. A system without an ethanol sensor will run richer and deliver lower mpg precisely because there will be more Oxygen in the exhaust stream.

Everything you said is correct except for the sensor part. We are not disagreeing on why E10 delivers less gas mileage.

My beef is with the rationale for E10 in the 1st place. Why do newer cars need oxygenated fuel? Older carbureted cars yes, but how many of them are still on the road? E10 is ripoff, and Ford is cheap.

e10 supposedly helps the fuel burn more complete to reduce hydrocarbon emissions, which helps reduce smog.

where did you learn about oxygen sensors? i know why you think it senses oxygen.. because everything you read says that, i was even taught this in school, but later learned from a tech class that it actually reacts to combustibles.

and the oxygenated part isn't what makes you get less milage its because it takes more fuel to obtain a "complete" burn in the cylinder. it has a different stoichemetric value than gasoline. look it up

if you want to know about the o2 sensor i can see if i can find it in one of my books to scan in

 

[BRUTUS_T_HOG]

Yes, EFI sensors account for variations of fuel octane, quality, etc. None of that is exclusive to E10. Your assertion is that the engine is changing because it's running E10. My point is that it does nothing specifically because it is E10, it is just making changes as it does for any fuel.

However, for E85, the engine DOES detect the ethanol content in the fuel and adjust timing specially for that. But for E10 it does nothing out of the ordinary.

i have never said that the computer detects e10, but it does detect the condition caused by burning e10 and adjusts accordingly- therefore it compensates for e10

 

[dla]

e10 supposedly helps the fuel burn more complete to reduce hydrocarbon emissions, which helps reduce smog.

where did you learn about oxygen sensors? i know why you think it senses oxygen.. because everything you read says that, i was even taught this in school, but later learned from a tech class that it actually reacts to combustibles.

and the oxygenated part isn't what makes you get less milage its because it takes more fuel to obtain a "complete" burn in the cylinder. it has a different stoichemetric value than gasoline. look it up

if you want to know about the o2 sensor i can see if i can find it in one of my books to scan in

E10 is 10% ethanol,90% gasoline. The overall stoichemetric change of the mixture can't account for the 10% or greater reduction in fuel economy. So the reason for the drop in fuel economy is simply that the extra Oxygen in the fuel causes a detected lean condition.

Ethanol replaces MTBE. Both are oxygenators. With today's closed-loop system there is no reason to use additives as the control system will strive for the perfect stoichemetric solution.

 

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You fellas are making my head spin!