I dont know if my Yaris 1nzfe runs closed loop at WOT or not - pretty sure it has a wide band O2 sensor though. How much leaner does a car run with ethanol " enhanced" fuel and will it toast the motor when I decarbonize the car once a week on the highway?
Safe to run Wide Open Throttle with E10 fuel?
- Thread starter ARCOgraphite
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Make sure the engine is good and warmed up (20 minute drive) and then while rolling at least 30MPH give her all you got. Nothing to worry about.
I do WOT's on my Santa Fe at least once a month and it has over 200K KM (120K miles) on it and runs E-10.
I do WOT's on my Santa Fe at least once a month and it has over 200K KM (120K miles) on it and runs E-10.
All we've had (in my county) is E10 since 1997. All the horror stories, very little has changed. Fuel mileage down 2 percent.
I hit WOT on the Accord every day to work. No worries.
I hit WOT on the Accord every day to work. No worries.
Originally Posted By: prax
Originally Posted By: 97 GTP
Then E10 requires only 3.5% more fuel than gas.
In theory. You're only calculating energy content.
In a non E85 vehicle that won't compensate for the additional octane that's all you really have to go by.
Originally Posted By: 97 GTP
Then E10 requires only 3.5% more fuel than gas.
In theory. You're only calculating energy content.
In a non E85 vehicle that won't compensate for the additional octane that's all you really have to go by.
Originally Posted By: 97 GTP
Originally Posted By: prax
Originally Posted By: 97 GTP
Then E10 requires only 3.5% more fuel than gas.
In theory. You're only calculating energy content.
In a non E85 vehicle that won't compensate for the additional octane that's all you really have to go by.
Are you implying that all people who have calculated a greater loss in gas mileage with E10 are not being truthful or that they're just wrong?
Alcohol and gasoline don't burn in exactly the same way. If they did, then yes you would get a 3.5% loss. You can't just look at numbers and pop out an answer. Engines are a more complex than that.
Originally Posted By: prax
Originally Posted By: 97 GTP
Then E10 requires only 3.5% more fuel than gas.
In theory. You're only calculating energy content.
In a non E85 vehicle that won't compensate for the additional octane that's all you really have to go by.
Are you implying that all people who have calculated a greater loss in gas mileage with E10 are not being truthful or that they're just wrong?
Alcohol and gasoline don't burn in exactly the same way. If they did, then yes you would get a 3.5% loss. You can't just look at numbers and pop out an answer. Engines are a more complex than that.
"Are you implying that all people who have calculated a greater loss in gas mileage with E10 are not being truthful or that they're just wrong?"
He might not be, but in my opinion that would be a safe assumption. Around here it was like prohibition when it happened. People made up all sorts of horror stores. Over a decade later, and nobody cares enough (in my hometown) to drive eight miles to get non-E10 gas unless it's for a boat.
Every engine is different, but I'd be skeptical of any claim over a 5% reduction in fuel economy.
He might not be, but in my opinion that would be a safe assumption. Around here it was like prohibition when it happened. People made up all sorts of horror stores. Over a decade later, and nobody cares enough (in my hometown) to drive eight miles to get non-E10 gas unless it's for a boat.
Every engine is different, but I'd be skeptical of any claim over a 5% reduction in fuel economy.
Originally Posted By: ARCOgraphite
I dont know if my Yaris 1nzfe runs closed loop at WOT or not
It doesn't matter, if it is open loop at WOT it still uses the fuel trims it learned while in closed loop. The computer does extrapolation to figure out how much extra fuel it needs to add at WOT to get the desired mixture.
I dont know if my Yaris 1nzfe runs closed loop at WOT or not
It doesn't matter, if it is open loop at WOT it still uses the fuel trims it learned while in closed loop. The computer does extrapolation to figure out how much extra fuel it needs to add at WOT to get the desired mixture.
Yup a a cleaver Japanese man is equipped in every Toyota. When you thromp on the gas, a big gong gets banged and wakes the man up, he then proceeds to work furiously with his calculator to figure out how much fuel is needed.
Sorry I felt like having fun...
Sorry I felt like having fun...
Originally Posted By: bepperb
Every engine is different, but I'd be skeptical of any claim over a 5% reduction in fuel economy.
I'd agree with that. Even on this site we have people claiming a measured 50%(!) drop in mileage running E10. If somebody sees their mileage cut in half when using E10, they're either not calculating right or are outright fibbing.
Every engine is different, but I'd be skeptical of any claim over a 5% reduction in fuel economy.
I'd agree with that. Even on this site we have people claiming a measured 50%(!) drop in mileage running E10. If somebody sees their mileage cut in half when using E10, they're either not calculating right or are outright fibbing.
Originally Posted By: brianl703
Originally Posted By: ARCOgraphite
I dont know if my Yaris 1nzfe runs closed loop at WOT or not
It doesn't matter, if it is open loop at WOT it still uses the fuel trims it learned while in closed loop. The computer does extrapolation to figure out how much extra fuel it needs to add at WOT to get the desired mixture.
I thought the fuel trims in close loop were primarily driven by the o2 sensor to run stoichiometric, but at WOT open loop it would use look up tables and trim by: MAF, temp, barometric, tachy, TPS, but it has NO reference as to the fuel oxygen content and cant trim for lean fuel chemistry. So back to my first question, does a engine ECU that utilises a wideband O2 lamda control use O2 sense in the WOT mixture control - and is this purely application dependant ( as in mazda DI motor yes it does, but in corolla 1.8 no it doesnt?
Originally Posted By: ARCOgraphite
I dont know if my Yaris 1nzfe runs closed loop at WOT or not
It doesn't matter, if it is open loop at WOT it still uses the fuel trims it learned while in closed loop. The computer does extrapolation to figure out how much extra fuel it needs to add at WOT to get the desired mixture.
I thought the fuel trims in close loop were primarily driven by the o2 sensor to run stoichiometric, but at WOT open loop it would use look up tables and trim by: MAF, temp, barometric, tachy, TPS, but it has NO reference as to the fuel oxygen content and cant trim for lean fuel chemistry. So back to my first question, does a engine ECU that utilises a wideband O2 lamda control use O2 sense in the WOT mixture control - and is this purely application dependant ( as in mazda DI motor yes it does, but in corolla 1.8 no it doesnt?
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Another italian tuneup Q: I try to do this (WOT) in 3rd gear and keep revs 500rpm below redline - but for how long? I try to do about 3 four-to-five second WOT run ups and let her cool down; DO you feel this abusive? I have my syn oil padded with 1/2 qt of M1 racing 4T superbike real syntetic - seems to be a great "additive" ; always has improved "seat of pants" on all oils I ever put it on top of - trying to say I think I have the oil robustness covered for this Italian tuneup beating.
Originally Posted By: ARCOgraphite
Another italian tuneup Q: I try to do this (WOT) in 3rd gear and keep revs 500rpm below redline - but for how long? I try to do about 3 four-to-five second WOT run ups and let her cool down; DO you feel this abusive?
I think it's fine. I run my vehicles up to redline often, and I'll occasionally run them there for a few seconds before shifting just to clean things out.
Did this with my old car all the time and sold it with 194K running smooth and not burning a drop.
Another italian tuneup Q: I try to do this (WOT) in 3rd gear and keep revs 500rpm below redline - but for how long? I try to do about 3 four-to-five second WOT run ups and let her cool down; DO you feel this abusive?
I think it's fine. I run my vehicles up to redline often, and I'll occasionally run them there for a few seconds before shifting just to clean things out.
Did this with my old car all the time and sold it with 194K running smooth and not burning a drop.
Originally Posted By: ARCOgraphite
I thought the fuel trims in close loop were primarily driven by the o2 sensor to run stoichiometric, but at WOT open loop it would use look up tables and trim by: MAF, temp, barometric, tachy, TPS, but it has NO reference as to the fuel oxygen content and cant trim for lean fuel chemistry. So back to my first question, does a engine ECU that utilises a wideband O2 lamda control use O2 sense in the WOT mixture control - and is this purely application dependant ( as in mazda DI motor yes it does, but in corolla 1.8 no it doesnt?
I know my SUV goes into open loop when I thromp on it.
I thought the fuel trims in close loop were primarily driven by the o2 sensor to run stoichiometric, but at WOT open loop it would use look up tables and trim by: MAF, temp, barometric, tachy, TPS, but it has NO reference as to the fuel oxygen content and cant trim for lean fuel chemistry. So back to my first question, does a engine ECU that utilises a wideband O2 lamda control use O2 sense in the WOT mixture control - and is this purely application dependant ( as in mazda DI motor yes it does, but in corolla 1.8 no it doesnt?
I know my SUV goes into open loop when I thromp on it.
Originally Posted By: ARCOgraphite
but it has NO reference as to the fuel oxygen content and cant trim for lean fuel chemistry.
It has memory. During WOT, it can and does use what it learned about the fuel oxygen content during non-WOT closed loop operation.
Get a decent scantool and watch the long-term fuel trims at WOT.
Quote:
but at WOT open loop it would use look up tables
Those look up tables were modified with information from the O2 sensor the moment the system went into closed loop.
but it has NO reference as to the fuel oxygen content and cant trim for lean fuel chemistry.
It has memory. During WOT, it can and does use what it learned about the fuel oxygen content during non-WOT closed loop operation.
Get a decent scantool and watch the long-term fuel trims at WOT.
Quote:
but at WOT open loop it would use look up tables
Those look up tables were modified with information from the O2 sensor the moment the system went into closed loop.
Originally Posted By: StevieC
I know my SUV goes into open loop when I thromp on it.
Practically all with non-wideband O2s do.
That does not, however (as I'm repeating myself for the third time, just for good measure) mean that at WOT it doesn't apply the air/fuel tables it built during closed loop operation. Rest assured that it does.
Think of it this way--if the computer knows that it needs to add an extra 5% fuel to keep the mixture correct during closed-loop operation, it will use that same adjustment during open-loop operation as well. That's grossly simplified, as the tables are multi-dimensional and engine load and RPM also figure into the tables (so that at a given engine load and speed the fuel trims can be stored into the table--and the computer can extrapolate and interpolate what it doesn't have information for).
All, in this context, the term "open loop" means is that it is ignoring current input from the O2 sensors because it is meaningless. It is not ignoring what it learned when the input from the O2 sensor was valid.
Take a scantool, watch long term fuel trim, and go WOT. Notice that the number does not drop to 0%, indicating that fuel trims are still being applied.
I know my SUV goes into open loop when I thromp on it.
Practically all with non-wideband O2s do.
That does not, however (as I'm repeating myself for the third time, just for good measure) mean that at WOT it doesn't apply the air/fuel tables it built during closed loop operation. Rest assured that it does.
Think of it this way--if the computer knows that it needs to add an extra 5% fuel to keep the mixture correct during closed-loop operation, it will use that same adjustment during open-loop operation as well. That's grossly simplified, as the tables are multi-dimensional and engine load and RPM also figure into the tables (so that at a given engine load and speed the fuel trims can be stored into the table--and the computer can extrapolate and interpolate what it doesn't have information for).
All, in this context, the term "open loop" means is that it is ignoring current input from the O2 sensors because it is meaningless. It is not ignoring what it learned when the input from the O2 sensor was valid.
Take a scantool, watch long term fuel trim, and go WOT. Notice that the number does not drop to 0%, indicating that fuel trims are still being applied.
When my 3800-powered car goes above 70% throttle, effectively the same as WOT according to the computer, it locks the long-term fuel trim at -1 as it goes open-loop. It starts back in closed loop when the throttle position goes below 70%. FWIW.
I ride a bike with sealed carbs from 1982. I unsealed the idle mix screw to richen it a tad with this E10 stuff.
It was set up to run lean on 100% gas. (1982 style EPA complaince.) Since I fixed the idle it stumbles a bit at about 10% throttle. Above that the power enrichment seems to take over and it runs great again. And it runs good at WOT. Plugs look super. Aircooled motor hasn't melted a piston or anything yet either.
No feedback system could botch this any worse than my non feedback system. As said above the fuel tables get rewritten at an appropriate pace. Everyone gets power enrichment; the newer stuff gets a crazy amount actually to keep NOx down by cooling off combustion temps.
It was set up to run lean on 100% gas. (1982 style EPA complaince.) Since I fixed the idle it stumbles a bit at about 10% throttle. Above that the power enrichment seems to take over and it runs great again. And it runs good at WOT. Plugs look super. Aircooled motor hasn't melted a piston or anything yet either.
No feedback system could botch this any worse than my non feedback system. As said above the fuel tables get rewritten at an appropriate pace. Everyone gets power enrichment; the newer stuff gets a crazy amount actually to keep NOx down by cooling off combustion temps.
E10 has hurt our mileage a bit, but in my case I would say about 11% on average across several platforms.
And 10% doesn't seem to have any serious side effects at all on anything but lawn mowers and very small displacement engines.
And 10% doesn't seem to have any serious side effects at all on anything but lawn mowers and very small displacement engines.
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