Hyundai Forums banner

E85 Experement on non-modified accent. DO NOT RECCOMEND

18K views 36 replies 17 participants last post by  charlescrown 
#1 ·
Hello everyone! So, just a couple days ago I was doing some research on E85 fuel (85% ethanol) because it is very cheap in my area, around $1.70 per gallon. And after a little bit of looking, I found that a lot of people run it in their non-flex-fuel cars just fine. Went to several different websites and blogs where people ran it in their regular, non modified cars just fine. This was not the case for me however, and I'll explain what happened.

The first time I tried it, I had about 1/8 of a tank of regular gas left, and decided to put in a couple gallons of E85 just to see how my car fared with it. It did well! No abnormal sounds, no higher temp readings, no engine light. Albeit, slightly poorer mpg than normal. So, after driving around with it for a day I had no issues, and the next day, I decided to fill it up with the E85, since it was so cheap. (only costed ~$14 to fill up from 1/4 of a tank) It was this time, on my way back home that the check engine light came on... That had me nervous right away, but I still didnt notice any abnormal behavior from the car. So I just kept on driving, and I noticed I was getting much lower mpg than normal, averaged 20 with mostly city driving, when normally I would get between 28-32 the way I drive. After I got home from that trip, It sat for a few hours, then went another ~30 mile trip and back home without issue. It wasnt 'till I started it up yesterday night that the engine had a little shudder right after it turned over. By that time I had used about a quarter of a tank of fuel, and decided to fill it the rest of the way with regular gasoline (which is already 10% ethanol in my area) to sort-of dilute the E85, since my engine clearly isn't running well on it.

I was having issues, but the car still worked observably fine, just very inefficiently, and with an engine light. BTW, at this point I had determined I would never use this fuel again, because clearly my engine doesn't take it well, and the poor MPG eats up any cost savings from the cheapness of the fuel. But this morning... Oh boy.. Got going to a friends house and what happens? Rev limiter wont let me rev higher than 3k RPM and I cant go any faster than 20-30 MPH... I had to crawl my way into a trailer park (on a road with a 55 MPH speed limit) where I called roadside assistance to have it towed. Lady said it would be about 2 hours, so I decided to crawl down to a little auto shop down the road to ask if they could help me with it, and they couldnt. So I went ahead and got it towed to the Hyundai dealership. The car is now sitting in the back of the dealership, and it's scheduled for a diagnostic on monday, which is costing me $125 itself...

Just sharing my experience so no one messes up like I have. I feel like a complete dumbass, but lesson learned I guess. :/

Does anyone have any idea how much they are likely to charge me to fix this? That would be a huge help...
 
See less See more
#2 ·
Depends on what they find. E85 is corrosive. Your fuel lines, pump/sender, injectors were not designed for e85. flex fuel vehicles typically have stainless steel components and special coatings to aid in corrosion resistance.

On to your issue. Probably just need to drain the e85 mix concoction in your tank, get some fuel in there and you should be ok.

I'm thinking in the ball park of 2 hr labor, and that may or may not include a diagnostic. You might save a few bucks by just telling them to drain the tank and fill with 87, and clear the codes.
 
#4 ·
Naah, I looked for such a warning in the manual before I did the first test, didn't find it. Not saying it was a smart thing to do though, because, it certainly wasn't.

Im betting that some sensor detected the fuel (octane level, maybe?) and some system decided to limit the rpm to protect the engine. I dont know this of course, just a guess.
 
#7 ·
Im betting that some sensor detected the fuel (octane level, maybe?) and some system decided to limit the rpm to protect the engine. I dont know this of course, just a guess.
Yes, your O2 sensor did it, and that's what triggered the check engine light. The ECU recorded the fault code and put your engine into "limp mode", which is what limited your RPM and speed.

Your fuel maps in the ECU are calibrated for the intended fuel and octane range. You cannot run any other fuel but what the car was designed for.

Most modern cars default to "limp mode" maps when sensor readings don't correspond to expected parameters, which is what happens when you use nonstandard or inferior fuels.

Running E85 long term in an engine not designed for it will lead to premature failure of a number of the systems mentioned by one of the posters above. Running only a half tank or so will not cause any appreciable damage.

Most likely, all the dealer will need to do is drain the fuel and refill it with proper E10, and clear the trouble codes to extinguish the CEL.
 
#11 ·
FWIW, the 2012 Accent manual has a 'fuel alcohol' warning. (Page 1-3) It doesn't specifically say not to use E85, but it does say not to use gasoline with more than 10% alcohol content.

As a point of interest, flex fuel vehicles running E85 get less mileage than when they run regular gas... It can be up to 20% less. The reason is that alcohol has less energy than gasoline so you need more to provide the same performance. So.. they have to charge less for E85 because very few people would pay the same price for a fuel that gave them less mileage.

As an example, here are the EPA ratings for an FFV 2015 Ford Explorer. They provide two ratings. One for gasoline and one for E85 (The EPA does this for all flex fuel vehicles). Compare Side-by-Side

Note that on pure gasoline, the average EPA rating is 20 MPG and on E85 it's 15 MPG. If you browse other flex fuel vehicles, you'll see that they all get less mileage on E85.
 
#12 ·
Why would you do this? To save a couple bucks. Our cars are not designed to run on e85 or tuned to run on e85. You would need bigger injectors and a different fuel system. e85 on a car that is not designed to use it will clog up your injectors.
 
#22 ·
Hard lesson learned.
 
#24 ·
Yes! Hyundai dealership quoted $520 but our local repair shop was able to give us a better price, so we had it towed there, where it will be looked at tomorrow. The said all that would need to be done is:

- Drain and replace the fuel with regular gasoline
- Clean fuel system
- New fuel filter

As dumb a mistake as I made, I actually know just a little bit about cars, and am skeptical if the cleaning and filter replacement is even necessary. Because, well, regular gas in my area has 10% ethanol already, and the car still runs, so wouldn't you be able to just replace the fuel and run it through the system until all the E85 left is burnt up? But even so, what can be done about the "limp mode" and engine light?

I'm not sure, but our local repair shop has had our business before, and have a history of being very honest about what needs to be done in these situations. So I'm hoping that if some shortcuts can be taken they'll tell us.
 
#25 ·
This post has FAIL written all over it.

First you put a cheaper fuel in your car, just to save a few bucks. Now, once the dealership quotes you a price, you jump ship for a local garage to fix it for cheaper.
You know the saying, you get what you pay for.

You would of been better off to let the dealership do the repairs and get it running properly. At Least if anything goes wrong, the dealership can help better then a backyard mechanic can.
 
#27 ·
Fail is a bit harsh. Maybe more of an easily avoidable mistake.

What I think is crazy is that you'd be willing to pay a dealership the $520 quoted price just to flush some fuel from his system.

PBX if you decide to go with your familiar mechanic the it would be wise to keep a receipt of the work done just in case.
 
#28 ·
Really. All we're doing is draining a tank and swapping a filter.
Ethanol is tricky...you can't see it burning! :eek:

Rick Mears found out the hard way in 1981:

https://www.youtube.com/watch?v=RwmfBp3U2Os

But you can put it out with water.
 
#30 ·
It's a computer, dude. You click the links and things magically appear before your very eyes!

Why, it's almost as easy as draining ethanol from your fuel tank!
 
#35 ·
Sorry about absolutely ditching this thread guys, I got really sick right after I got the car repaired and sortof forgot about it. :/

Now, as for the repair, it only costed ~$320 at my local repair shop. Almost half what the dealership would have charged me if you include the 'diagnostic' they wanted to give me. I generally have no complaints about the dealership however, they have always been very kind to us. (that $320 included the cost of towing it from the dealership to the shop, about 15 miles.)

Moving along to warranty. The dealership didn't mention my warranty, so I dont know the status of it. But I kind of doubt its voided.

Car has been running great since! All is well now!
 
#36 ·
Hello everyone! So, just a couple days ago I was doing some research on E85 fuel (85% ethanol) because it is very cheap in my area, around $1.70 per gallon. And after a little bit of looking, I found that a lot of people run it in their non-flex-fuel cars just fine. Went to several different websites and blogs where people ran it in their regular, non modified cars just fine. This was not the case for me however, and I'll explain what happened.

The first time I tried it, I had about 1/8 of a tank of regular gas left, and decided to put in a couple gallons of E85 just to see how my car fared with it. It did well! No abnormal sounds, no higher temp readings, no engine light. Albeit, slightly poorer mpg than normal. So, after driving around with it for a day I had no issues, and the next day, I decided to fill it up with the E85, since it was so cheap. (only costed ~$14 to fill up from 1/4 of a tank) It was this time, on my way back home that the check engine light came on... That had me nervous right away, but I still didnt notice any abnormal behavior from the car. So I just kept on driving, and I noticed I was getting much lower mpg than normal, averaged 20 with mostly city driving, when normally I would get between 28-32 the way I drive. After I got home from that trip, It sat for a few hours, then went another ~30 mile trip and back home without issue. It wasnt 'till I started it up yesterday night that the engine had a little shudder right after it turned over. By that time I had used about a quarter of a tank of fuel, and decided to fill it the rest of the way with regular gasoline (which is already 10% ethanol in my area) to sort-of dilute the E85, since my engine clearly isn't running well on it.

I was having issues, but the car still worked observably fine, just very inefficiently, and with an engine light. BTW, at this point I had determined I would never use this fuel again, because clearly my engine doesn't take it well, and the poor MPG eats up any cost savings from the cheapness of the fuel. But this morning... Oh boy.. Got going to a friends house and what happens? Rev limiter wont let me rev higher than 3k RPM and I cant go any faster than 20-30 MPH... I had to crawl my way into a trailer park (on a road with a 55 MPH speed limit) where I called roadside assistance to have it towed. Lady said it would be about 2 hours, so I decided to crawl down to a little auto shop down the road to ask if they could help me with it, and they couldnt. So I went ahead and got it towed to the Hyundai dealership. The car is now sitting in the back of the dealership, and it's scheduled for a diagnostic on monday, which is costing me $125 itself...

Just sharing my experience so no one messes up like I have. I feel like a complete dumbass, but lesson learned I guess. :/

Does anyone have any idea how much they are likely to charge me to fix this? That would be a huge help...

Sorry to necro the thread, but in hindsight, you kind of should have blended the fuel a little at a time to get an idea of where the butter zone is. Most cars can handle E30 just fine even with stock fuel systems with hardly a loss in mileage and without leaning out. And our cars can already handle E15 with no noticeable loss of efficiency, so E30 shouldn't see much of a loss, maybe 1 or 2 mpg.

Corrosion isn't a problem either as it's not much more corrosive than gasoline, it's the water the fuel can absorb causing rust over time, which itself will not happen as long as you keep the fuel vapor and emissions system functional and you don't let the car sit with old fuel like people do with boats for a year+.

It's unfortunate the experiment ended that way for you, but that's the nature of experimentation, unfortunately. But at least you were able to get everything fixed, professionally to boot. How is it running today? Everything still holding up?
 
#37 ·
As already stated just drain the tank and fill up with std petrol and hope for the best. When using E85 you need to burn approx 40% more fuel to get the air/fuel ratio right. It's gone super lean and hopefully all that has happened is it's in limp mode with no engine damage.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top