Five Things You May Not Know About Flex-Fuel Engines
1. They’re pretty much the same as a normal engines. Aside from a different set of spark plugs, injectors that can pulse more fuel, and a more corrosion resistant fuel system, flex-fuel engines are essentially identical to regular old gasoline engines. To see what “essentially” means, read more below.
2. When you run E85, your fuel economy drops 20-30%. This is because ethanol contains less chemical energy than gasoline. Put another way, ethanol burns cooler than gas, so it takes more than one gallon of ethanol to do the same amount of traveling that you can do on one gallon of gas. Provided that E-85 is at least 20-30% cheaper than gas, it’s a push. Otherwise, running E-85 might be costing you money.
3. E-85 absorbs water like crazy. That’s not a scientific observation of course, but it’s a good description. Check this out:
ethanol is hygroscopic by nature. This means that it immediately soaks up water both in liquid form and as condensation right from the atmosphere. Hence ethanol cannot be transported through petrol pipelines. Worse yet is that any prolonged exposure to the air itself can begin to dilute ethanol (due to water absorption)
This explanation from the Energy Refuge blog is specifically about the transportation problems associated with pure ethanol, but all of the above information applies to E-85 fuel.
E-85 will absorb whatever water is nearby, and given enough time it will dilute itself enough to cause combustion problems. While is is very rare, it *is* technically possible. The downside to water absorption is that burning “wet” E-85 can cause excessive amounts of formic acid to be created during combustion. Formic acid can eat engines, which means that…
4. A flex fuel engine’s parts are treated to resist formic acid. Because the risk of water contamination in an E-85 engine are fairly high, automakers use a special nitride coating on all the internal engine parts that may be exposed. This prevents excessive wear if a particularly watery batch of E85 is burned.
5. Manufacturers may recommend more frequent oil changes when running E-85. If you live in an area where E-85 is readily available and cost effective, you may be using it every day. If so, your local dealership may suggest you change your oil more frequently. Their reason? Acids formed during ethanol combustion can reduce the lubrication properties of motor oil, therefore requiring more frequent changes.
Unfortunately, this is pure hogwash. Most modern oils contain more than enough detergents to nuetralize the acids that E-85 may produce without compromising lubrication, so they do not need to be changed any earlier than normal. Read more about why more frequent oil changes are not needed if you’re running E-85 if you’d like to find out more.
6. (Bonus!) When your manufacturer built your flex-fuel vehicle, they got a special fuel economy credit from the government. In a system that’s both unseemly and absurd, auto manufacturers are given fuel economy “credits” for building flex-fuel vehicles even though these vehicles don’t get better fuel economy. The TerraPass blog has a great post that explains how a Chevy Suburban was credited with a 30mpg fuel economy rating despite actually getting 12-16 mpg – check it out.
Finally, for you Tundra owners out there, a flex-fuel engine is not compatible with the TRD Supercharger.
#5 and #6 I didn’t know. For #5 then, why do mfgs. state to change oil at 2500 miles if use over 50% of the time E85? You would think the car mfgs. would know what they are talking about don’t you think? #6 is a crock of hogwash. Fuel credits to build E85 vehicles when in fact E85 reduces fuel economy by around 25%. This seems to contradict saving fuel don’t you think even though not pure gas or even E10 gas. Unless I am strapped for cash or over 25% cheaper E85 vs. E10, I will never buy E85 since I lose 25% fuel economy from say 13.5 from 17 mpg running E10. Lately here in the midwest, E85 has been only 22% cheaper so it is not worth using. But, a few years ago, E85 was over 30% cheaper and then it pays to use it more often, but never over 50% of the time since I still don’t trust the internal parts of the engine to handle the E85 stuff.
#5 and #6 I didn’t know. For #5 then, why do mfgs. state to change oil at 2500 miles if use over 50% of the time E85? You would think the car mfgs. would know what they are talking about don’t you think? #6 is a crock of hogwash. Fuel credits to build E85 vehicles when in fact E85 reduces fuel economy by around 25%. This seems to contradict saving fuel don’t you think even though not pure gas or even E10 gas. Unless I am strapped for cash or over 25% cheaper E85 vs. E10, I will never buy E85 since I lose 25% fuel economy from say 13.5 from 17 mpg running E10. Lately here in the midwest, E85 has been only 22% cheaper so it is not worth using. But, a few years ago, E85 was over 30% cheaper and then it pays to use it more often, but never over 50% of the time since I still don’t trust the internal parts of the engine to handle the E85 stuff.
The problem now is finding a pump that doesn’t have E-85. Dang near everyone has it now. You’re stuck with that fuel.
The problem now is finding a pump that doesn’t have E-85. Dang near everyone has it now. You’re stuck with that fuel.
my 2010 d/c is not marked as flex fuel. also, i’ve never seen a e-85 pump im mississippi or tennessee. so, if i’m in an area that only has e-85, can i still use it temporarily until i find normal gas or e-10?
i also think it’s stupid to use a food source to make an inefficient fuel. switch grass is a better candidate for this but there’s no money to be made growing a weed. when corn prices shot through the roof due to higher demand caused by ethanol mandates, our food prices went up. corn is used to make dog food, catfish feed, hog feed, cattle feed, chicken feed, human food, etc, etc. all of these went up due to the corn being allocated to fuel production. economics 101; the greater the demand equals a greater price, as long as supply is limited. also with more corn acreage being allocated, there is less acreage for other foods to be grown.
my 2010 d/c is not marked as flex fuel. also, i’ve never seen a e-85 pump im mississippi or tennessee. so, if i’m in an area that only has e-85, can i still use it temporarily until i find normal gas or e-10?
i also think it’s stupid to use a food source to make an inefficient fuel. switch grass is a better candidate for this but there’s no money to be made growing a weed. when corn prices shot through the roof due to higher demand caused by ethanol mandates, our food prices went up. corn is used to make dog food, catfish feed, hog feed, cattle feed, chicken feed, human food, etc, etc. all of these went up due to the corn being allocated to fuel production. economics 101; the greater the demand equals a greater price, as long as supply is limited. also with more corn acreage being allocated, there is less acreage for other foods to be grown.
also, there are a few gas stations here that market themselves as carring “pure” gasoline. they are about 10 cents a gallon higher but well worth it compared to e-10.
also, ethanol will kill you weed wackers, chainsaws and lawn mowers. when i cant get pure gasoline, i run a little seafoam in the fuel as suggested by napa and autozone. i also heard that stabil is strongly suggested. i’m not sure how true this is, but i’d rather not risk my gas powered tools. also, my old 1995 z-71 ran fine until she had to run ethanol. i cant prove it, but it seems very coincidental.
also, there are a few gas stations here that market themselves as carring “pure” gasoline. they are about 10 cents a gallon higher but well worth it compared to e-10.
also, ethanol will kill you weed wackers, chainsaws and lawn mowers. when i cant get pure gasoline, i run a little seafoam in the fuel as suggested by napa and autozone. i also heard that stabil is strongly suggested. i’m not sure how true this is, but i’d rather not risk my gas powered tools. also, my old 1995 z-71 ran fine until she had to run ethanol. i cant prove it, but it seems very coincidental.
There’s probably no reason to mention this, but E85 is an excellent race fuel (about 105-110 octane rating)as well as burning cooler than gasoline. I use it in my 06 Mitsubishi EVO and 03 Mustang Cobra with excellent results. Because E85 burns cooler and has a higher octane rating than gas i am able to run with higher boost on both vehicles. Fuel economy does suffer a bit (anywhere from 20-30%) so I had to upgrade to higher flowing fuel injectors and fuel pump to compensate for the extra flow that was needed. E85 is also about 20% cheaper at the pump then regular gasoline, not to mention race fuel. With that said i wouldn’t use it on a daily driven vehicle because of the fuel mileage issue.
There’s probably no reason to mention this, but E85 is an excellent race fuel (about 105-110 octane rating)as well as burning cooler than gasoline. I use it in my 06 Mitsubishi EVO and 03 Mustang Cobra with excellent results. Because E85 burns cooler and has a higher octane rating than gas i am able to run with higher boost on both vehicles. Fuel economy does suffer a bit (anywhere from 20-30%) so I had to upgrade to higher flowing fuel injectors and fuel pump to compensate for the extra flow that was needed. E85 is also about 20% cheaper at the pump then regular gasoline, not to mention race fuel. With that said i wouldn’t use it on a daily driven vehicle because of the fuel mileage issue.
E85 might be higher octane, but with 2 somewhat expensive racing type cars, why would you risk ruining your engine using E85 TC8? E85 agree or even E10 is not good for smaller engines like outboards, lawnmowers, roto-tillers, weed whackers, etc. and try to buy 93 octane no ethanol pure 100% gas, although paying a premium at about 30 cents more per gallon, but besides the lawnmowers, I do not use those small engines that frequently, so I pay the increase to hopefully make the smaller engines run better and last longer. Although, I begin to wonder how long the 100% 93 octane gas is sitting in the holding tanks at the gas stations since not too many people use that type of gas thus creating stale/possibly watered down bad gas as well. I also use seafoam and/or mystery marvel oil which seems to help, so far, good luck no problems in the gas tanks.
E85 might be higher octane, but with 2 somewhat expensive racing type cars, why would you risk ruining your engine using E85 TC8? E85 agree or even E10 is not good for smaller engines like outboards, lawnmowers, roto-tillers, weed whackers, etc. and try to buy 93 octane no ethanol pure 100% gas, although paying a premium at about 30 cents more per gallon, but besides the lawnmowers, I do not use those small engines that frequently, so I pay the increase to hopefully make the smaller engines run better and last longer. Although, I begin to wonder how long the 100% 93 octane gas is sitting in the holding tanks at the gas stations since not too many people use that type of gas thus creating stale/possibly watered down bad gas as well. I also use seafoam and/or mystery marvel oil which seems to help, so far, good luck no problems in the gas tanks.
I would never convert my 08 Tundra to run E85 as fuel economy will suffer, especially as it’s my daily driver, but as a race fuel for my other vehicles i really don’t see a downside beside more fill-ups when i do drive them. The first few oil changes after converting to E85 i had the motor oil tested and found no issues running E85 so i’m currently back to 5000 mile service intervals using synthetic oil. There’s really no issues with water absorbtion as fuel tanks are sealed fairly well and the fuel will never sit long enough anyway. The reason vehicles break down when running on E85 has nothing to do with the fuel itself, but the amount of fuel needed to properly feed the engine. Keep in mind E85 doesn’t have the combustion energy that gas does, so it will take more E85 to create the same energy. If you don’t increase the fuel pump and fuel injectors accordingly along with a device (or reflashing the ecu) to drive them the engine will lean out which will cause detonation, and that’s what kills engines. My 2 cents.
I would never convert my 08 Tundra to run E85 as fuel economy will suffer, especially as it’s my daily driver, but as a race fuel for my other vehicles i really don’t see a downside beside more fill-ups when i do drive them. The first few oil changes after converting to E85 i had the motor oil tested and found no issues running E85 so i’m currently back to 5000 mile service intervals using synthetic oil. There’s really no issues with water absorbtion as fuel tanks are sealed fairly well and the fuel will never sit long enough anyway. The reason vehicles break down when running on E85 has nothing to do with the fuel itself, but the amount of fuel needed to properly feed the engine. Keep in mind E85 doesn’t have the combustion energy that gas does, so it will take more E85 to create the same energy. If you don’t increase the fuel pump and fuel injectors accordingly along with a device (or reflashing the ecu) to drive them the engine will lean out which will cause detonation, and that’s what kills engines. My 2 cents.
mk – To your first point, I agree. Don’t see how there’s a government fuel economy credit for this system. I also haven’t seen E85 at a price point that made economic sense…but some companies use it because the net carbon placed in the environment is much lower (practically zero).
Mickey – Interesting. I see lots of 85 octane, but E85 is sort of rare in my neck of the woods.
Danny – I’m with you all the way on the economics of corn. Brazil makes ethanol with sugar cane, and while that’s not really economic either, it’s better than corn. As I’m sure you know, the holy grail of ethanol production is to use “cellulosic feedstocks” – things like corn husks and grass clippings – to make E85. There is some interesting research going on related to termites: http://gas2.org/2010/08/26/florida-researchers-moving-closer-to-using-termite-guts-for-better-ethanol/
Maybe someday we’ll make our own gasoline alternative using some sort of termite based fuel machine…LOL. It’s exciting to think about being petrol free (or at least much less dependent).
As for your question, you probably could get away with running a few gallons of E85 in a regular engine without any long-term damage, but I wouldn’t risk it. Better to pay for a tow bill or rental car…a watery batch of E85 could destroy your fuel system. That my explain why E10 ruins lawn tools that are likley to accumulate moisture as they sit unused for days or weeks at a time.
TC8 – It’s funny you say that, because the racing uses almost made the list! Great point. When an engine is designed/tuned for E85, the compression ratio can be much higher, efficiency can be better, etc. It’s much cheaper than racing fuel too…and I wouldn’t have thought of that one. Great comment!
mk – I think TC8’s response to your second comment is correct – the risk to vehicles is low. However, for small gas powered motors not designed for gas/ethanol mixtures, the risk is higher…especially because they sit so long between uses. That’s a formula for absorbing water I think.
mk – To your first point, I agree. Don’t see how there’s a government fuel economy credit for this system. I also haven’t seen E85 at a price point that made economic sense…but some companies use it because the net carbon placed in the environment is much lower (practically zero).
Mickey – Interesting. I see lots of 85 octane, but E85 is sort of rare in my neck of the woods.
Danny – I’m with you all the way on the economics of corn. Brazil makes ethanol with sugar cane, and while that’s not really economic either, it’s better than corn. As I’m sure you know, the holy grail of ethanol production is to use “cellulosic feedstocks” – things like corn husks and grass clippings – to make E85. There is some interesting research going on related to termites: http://gas2.org/2010/08/26/florida-researchers-moving-closer-to-using-termite-guts-for-better-ethanol/
Maybe someday we’ll make our own gasoline alternative using some sort of termite based fuel machine…LOL. It’s exciting to think about being petrol free (or at least much less dependent).
As for your question, you probably could get away with running a few gallons of E85 in a regular engine without any long-term damage, but I wouldn’t risk it. Better to pay for a tow bill or rental car…a watery batch of E85 could destroy your fuel system. That my explain why E10 ruins lawn tools that are likley to accumulate moisture as they sit unused for days or weeks at a time.
TC8 – It’s funny you say that, because the racing uses almost made the list! Great point. When an engine is designed/tuned for E85, the compression ratio can be much higher, efficiency can be better, etc. It’s much cheaper than racing fuel too…and I wouldn’t have thought of that one. Great comment!
mk – I think TC8’s response to your second comment is correct – the risk to vehicles is low. However, for small gas powered motors not designed for gas/ethanol mixtures, the risk is higher…especially because they sit so long between uses. That’s a formula for absorbing water I think.
You say an e85 engine needs different spark plugs to pulse more fuel… don’t you mean different fuel injectors? Every modern E85 engine I am aware of has fuel injectors with a much wider range of fuel delivery since they may need to pump out almost twice as much E85 vs. gasoline in similar instances.
You say an e85 engine needs different spark plugs to pulse more fuel… don’t you mean different fuel injectors? Every modern E85 engine I am aware of has fuel injectors with a much wider range of fuel delivery since they may need to pump out almost twice as much E85 vs. gasoline in similar instances.
texmln – Aargh! Typo!! 🙂 Thanks for catching it – I adjusted the article.
That’s what I get for writing posts at 11pm!
texmln – Aargh! Typo!! 🙂 Thanks for catching it – I adjusted the article.
That’s what I get for writing posts at 11pm!
So what’s the real benefit of running E85 in a Tundra, especially if you live in a region that doesn’t offer it? I may have missed that part when I browsed the article.
So what’s the real benefit of running E85 in a Tundra, especially if you live in a region that doesn’t offer it? I may have missed that part when I browsed the article.
TXTee – I think that there are some places where E-85 is financially attractive, and of course that will change if oil prices head back up.
The other reason that E85 is purchased is that it reduces a company’s carbon footprint. Some companies use E85 exclusively in their fleet vehicles to make an environmental statement.
TXTee – I think that there are some places where E-85 is financially attractive, and of course that will change if oil prices head back up.
The other reason that E85 is purchased is that it reduces a company’s carbon footprint. Some companies use E85 exclusively in their fleet vehicles to make an environmental statement.
Hmmm so the consumer ends up paying for the E85 image. LOL…got your points, Jason. Thanks as always. Glad to see the articles are still here. Was the feed notification not working?
Hmmm so the consumer ends up paying for the E85 image. LOL…got your points, Jason. Thanks as always. Glad to see the articles are still here. Was the feed notification not working?
TXTee – Not sure – are you saying that you weren’t getting any RSS notices?
TXTee – Not sure – are you saying that you weren’t getting any RSS notices?
Something like that….I didn’t see the posts on the forum page’s left side link and assumed there was nothing new. We also keep the RSS feed on the GCT site to notify members when there’s a new article…..and they all came flooding in one day.
Something like that….I didn’t see the posts on the forum page’s left side link and assumed there was nothing new. We also keep the RSS feed on the GCT site to notify members when there’s a new article…..and they all came flooding in one day.
TXTee – No idea…could be the GCT RSS feed, could be something I’ve done, could be a random error. Hopefully it’s fixed now!
TXTee – No idea…could be the GCT RSS feed, could be something I’ve done, could be a random error. Hopefully it’s fixed now!
Hi, I just purchased a FF Tundra. I had thoughts of putting a SC on it until I just found out it is incompatible with the FF 5.7. Is this true and is there anything I can do to make it possible to install a SC. thanks,
Jon
Hi, I just purchased a FF Tundra. I had thoughts of putting a SC on it until I just found out it is incompatible with the FF 5.7. Is this true and is there anything I can do to make it possible to install a SC. thanks,
Jon
Jon – Sorry to say it, but no. See the comments on this post for more info: https://www.tundraheadquarters.com/blog/2008/06/06/trd-57-tundra-supercharger-specs-504-hp-and-550-lb-ft-torque/
Jon – Sorry to say it, but no. See the comments on this post for more info: https://www.tundraheadquarters.com/blog/2008/06/06/trd-57-tundra-supercharger-specs-504-hp-and-550-lb-ft-torque/
have ran many different vehicles on E-85 for about 15 years and absolutely love it fo the following reasons;
1. It is 100% American Made so I am doing my part to stop the transfer of wealth to the Middle East. We import 1 billion dollars of crude oil per day and much of it is from hostile reagions of the world.
2. Much cleaner than gasoline.
3. It is renewable
Also, If you are most concerned about the mileage, I often blend it at 30% ethanol 70% gasoline and get very minimal mileage loss and I have found it to actually be less cost per mile than E-10.
have ran many different vehicles on E-85 for about 15 years and absolutely love it fo the following reasons;
1. It is 100% American Made so I am doing my part to stop the transfer of wealth to the Middle East. We import 1 billion dollars of crude oil per day and much of it is from hostile reagions of the world.
2. Much cleaner than gasoline.
3. It is renewable
Also, If you are most concerned about the mileage, I often blend it at 30% ethanol 70% gasoline and get very minimal mileage loss and I have found it to actually be less cost per mile than E-10.
Hi all, i want to buy a 2011 or 2012 NON-FLEX FUEL Toyota Crewmax 4×4 but i can’t seem to find it. All the dealers are claiming it does not exist. I can find it on the Toyota page and on the Edmunds page, but everyone is claiming Toyota only makes Flexfuel crewmax 4×4 now. any ideas?
if not, can you suggest an alternate vehicle?
Hi all, i want to buy a 2011 or 2012 NON-FLEX FUEL Toyota Crewmax 4×4 but i can’t seem to find it. All the dealers are claiming it does not exist. I can find it on the Toyota page and on the Edmunds page, but everyone is claiming Toyota only makes Flexfuel crewmax 4×4 now. any ideas?
if not, can you suggest an alternate vehicle?
Firstseeker – You can buy a non-flex fuel Tundra, but you have to look in a different region. My suggestion? Check with a Toyota dealer in Phoenix or Dallas. In years past, people could buy non-flex fuel Tundras in those markets.
Firstseeker – You can buy a non-flex fuel Tundra, but you have to look in a different region. My suggestion? Check with a Toyota dealer in Phoenix or Dallas. In years past, people could buy non-flex fuel Tundras in those markets.
Hello All,
Im a toyota driver in holland and have problems with my Tundra flexfuel 5.7 flexfuel 2012 , the problem is that we having start problems,the Car gives in his history (OBD) 86% ethanol and we never use that in holland, but the car needs to be reset every month because when its reset the percentage is 0 % and no problems,after 1 month 86% and no starting anymore, nobody can help me here so perhaps anybody can give me some answers,we dont get support from Toyota USA because this are side import cars.
The locall dealers dont know this cars and we cant find a sensor Please who can help me,
regards gerard jonkman
Hello All,
Im a toyota driver in holland and have problems with my Tundra flexfuel 5.7 flexfuel 2012 , the problem is that we having start problems,the Car gives in his history (OBD) 86% ethanol and we never use that in holland, but the car needs to be reset every month because when its reset the percentage is 0 % and no problems,after 1 month 86% and no starting anymore, nobody can help me here so perhaps anybody can give me some answers,we dont get support from Toyota USA because this are side import cars.
The locall dealers dont know this cars and we cant find a sensor Please who can help me,
regards gerard jonkman
Doesn’t sound like flex-fuel offers any practical benefits over regular gasoline. But I guess the government’s propensity to kowtow to the eco-terrorists isn’t rooted in any kind rationale thought process.
At least it keeps corn-growing farmers in business. 🙂
Doesn’t sound like flex-fuel offers any practical benefits over regular gasoline. But I guess the government’s propensity to kowtow to the eco-terrorists isn’t rooted in any kind rationale thought process.
At least it keeps corn-growing farmers in business. 🙂
[…] This link is to Tundra Headquarters where I found some facts about the Flex Fuel Engines that were interesting. Five Things You May Not Know About Flex-Fuel Engines | Tundra Headquarters Blog […]
[…] This link is to Tundra Headquarters where I found some facts about the Flex Fuel Engines that were interesting. Five Things You May Not Know About Flex-Fuel Engines | Tundra Headquarters Blog […]
[…] Tagged: 0 Thread(s) Quoted: 52 Post(s) All you need to know about FFV's in general. Five Things You May Not Know About Flex-Fuel Engines | Tundra Headquarters Blog 12' CM Tundra, SR5, 5.7L, 4×4 14' Tacoma TRD Sport LB 4×4 ColoradoTJ is online […]
[…] Tagged: 0 Thread(s) Quoted: 52 Post(s) All you need to know about FFV's in general. Five Things You May Not Know About Flex-Fuel Engines | Tundra Headquarters Blog 12' CM Tundra, SR5, 5.7L, 4×4 14' Tacoma TRD Sport LB 4×4 ColoradoTJ is online […]