Alfa Romeo Giulia Forum banner

Mistakenly filled my gas tank up with E85 this morning. Q4

4511 Views 47 Replies 24 Participants Last post by  Avnyc11
I mistakenly filled my gas tank up with E85 this morning. I am uncertain if I should drive the car or have it towed to get the gas tank flushed and new 91 gas put in. It is a 2019 Q4 Giuliani. I am at the gas station and uncertain what to do.
21 - 40 of 48 Posts
1 tank of E85 will do nothing to gall or cause rapid wear to an electric fuel pump. Gasoline doesn’t lubricate an electric fuel pump. Your diesel injector pump is a whole different animal. They are big money and typically warrantied for 5-7 yrs or 100K miles.
Just an FYI, The HPFP is not electric ,its mechanical.
  • Like
Reactions: 1
Just an FYI, The HPFP is not electric ,its mechanical.
I stand corrected on the electric pump.
I stand corrected on the electric pump.
The electric low pressure fuel pump is most likely diaphragm based. Nothing to gall, just a piece of rubber that may or may not react badly to E85.

The high pressure fuel pump is entirely different. To produce the ~4000psi needed to feed a direct injection fuel system a piston type pump is typically required. The service manual has a picture of the camshaft actuated unit (which is a huge PITA to R&R) but nothing about what is inside.
My guess is that the car is fine to drive in low boost until you an run it low enough to add more fuel. I wonder if you ran the tank halfway and filled it with 87 if it would balance out energy-density wise. I would definitely avoid full boost.
  • Like
Reactions: 2
I am in the camp of those who feel it would be best to pay to have the car taken to somewhere where the fuel can be drained. If at some point in the future, the owner notes some troublesome change in his car's performance he will always wonder if running the wrong fuel is the cause. I have made mistakes in the past with my automotive adventures, some were costly, but I always 'bit the bullet' and spent the money and time to correct the issue, before something even more expensive occurred. If in the future something just isn't quite right how will the owner know where to begin to sort it out, and at what cost. NV
  • Like
Reactions: 1
I suspect the worst thing to do would be to let the car sit after having run, leaving the fuel lines and pump bathed with ethanol.
The rubber and seals have been made to handle ethanol for quite a few years now. The problem is the car will only adjust the fuel trims so far and then set the check engine light. You. CAn get away with E30 just fine and car will adjust perfectly to it. E85 however the stft and ltft will be too far out of tolerance. And pop the cel on.
When tuning and having a intermittent problem with know we usually will throw in a few gallons of E85 to see if the knock goes away. That will let us know if it’s false knock or not like loose motor mounts or headers hitting something and such.
  • Like
Reactions: 2
The rubber and seals have been made to handle ethanol for quite a few years now. The problem is the car will only adjust the fuel trims so far and then set the check engine light. You. CAn get away with E30 just fine and car will adjust perfectly to it. E85 however the stft and ltft will be too far out of tolerance. And pop the cel on.
When tuning and having a intermittent problem with know we usually will throw in a few gallons of E85 to see if the knock goes away. That will let us know if it’s false knock or not like loose motor mounts or headers hitting something and such.
Unless it was from a can it is not full E-85. Pump E is usually between e51-e70. Especially now during a gas apocalypse. So after mixing it with whatever fuel he has in system he most likely around E40-50. Like others said stay in low boost and should be fine. Fill it up at half way again. Cars seals and rings etc are designed to handle ethanol in everyday gas
  • Like
Reactions: 1
Talking about draining the tank, isn't the old school SOP of putting a low diameter hose through the top of the tank (gas cap orifice) and suck the gasoline (and trying not to swallow anything) an option in these cars?. One only needed a hose and a big gas plastic can (or two) to empty almost all the tank. Isn't that possible these days?. One could even sell the wrong gas and the plastic gas cans to other who could use it.
like Alfa Philly said right now it’s still the winter-spring blend. Theoretically the car should be perfectly fine if not beat on.
Talking about draining the tank, isn't the old school SOP of putting a low diameter hose through the top of the tank (gas cap orifice) and suck the gasoline (and trying not to swallow anything) an option in these cars?. One only needed a hose and a big gas plastic can (or two) to empty almost all the tank. Isn't that possible these days?. One could even sell the wrong gas and the plastic gas cans to other who could use it.
Nope. Cars from the recent past have some kind of restriction or valve that prevents from inserting the siphon hose. AMHIK.
  • Like
Reactions: 1
Unless it was from a can it is not full E-85. Pump E is usually between e51-e70. Especially now during a gas apocalypse. So after mixing it with whatever fuel he has in system he most likely around E40-50. Like others said stay in low boost and should be fine. Fill it up at half way again. Cars seals and rings etc are designed to handle ethanol in everyday gas
I find it difficult to believe that pump fuel is not as advertised. We are not talking about E unknown, but fuel advertised as E85. At least in California there is pretty strict oversight that pumps dispense the right amount of the right fuel. Otherwise you will end up getting the same fuel when you select 87, 89, 91 or 93 octane, just for different prices.
I find it difficult to believe that pump fuel is not as advertised. We are not talking about E unknown, but fuel advertised as E85. At least in California there is pretty strict oversight that pumps dispense the right amount of the right fuel. Otherwise you will end up getting the same fuel when you select 87, 89, 91 or 93 octane, just for different prices.
E85 is different. They have seasonal blends that change the ratio and octane. You can look it up and go by a calendar really. Problem is E85 don’t like the cold and don’t like to start. So they add more gas to it essentially lowering the ratio from 85% to like 65-70.
When I was tuned on E85 in another car you could tell when the different blends came through due to the short term fuel trims and then long term. Both would start pulling fuel like crazy. Like 15%-20%
  • Like
Reactions: 1
Every car for the past 10 plus years has fuel system components that can withstand ethanol. Thats not why e85 is forbidden in the manual.

Its forbidden because the car is not tuned for flex fuel which requires a sensor that measures the percentage of ethanol in the gasoline pumped in and adjusts fueling tables based on that.

If you don't adjust the fueling tables you rely on the standard closed loop feedback which relies on short term and ling term fuel trimming.

There is only so much room in fuel trims though. Do you could potentially go lean.

This may also require larger fuel pumps or injectors due to the approx 30 percent additional fuel demands of e85.


Bottom line is if you were to baby the car for 3/4 tank and then fill with non ethanol youll be good to go.
See less See more
  • Like
Reactions: 1
I find it difficult to believe that pump fuel is not as advertised. We are not talking about E unknown, but fuel advertised as E85. At least in California there is pretty strict oversight that the pumps dispense the right amount of the right fuel. Otherwise you will end up getting the same fuel when you select 87, 89, 91 or 93 octane, just for different prices.
Some pumps say E-51 to E-83. Ethanol isn’t regulated Like others have stated. Only way to get full E-85 is from can or at a track. The best you may see on a pump at a station if your lucky is 80-82. And believe me those stations sell out quick. Because of the wide range Most tuner cars have a ethanol gauge to sense what the E level is.
Some pumps say E-51 to E-83. Ethanol isn’t regulated Like others have stated. Only way to get full E-85 is from can or at a track. The best you may see on a pump at a station if your lucky is 80-82. And believe me those stations sell out quick. Because of the wide range Most tuner cars have a ethanol gauge to sense what the E level is.
Correct. Youll almost never get exactly e85 from the pump which is why all e85 compatible cars must have ethanol sensors in them that continuously assess etoh content.
  • Like
Reactions: 1
I could be mistaken, and there’s no way for me to confirm this, but when i purchased my Giulia, the salesman said they topped off the tank before i got there to pick up the car. A few days later i remembered him making some flippant comment about how “any gas will do”, when i initially took it for a test drive.

I have no idea what gas they put into the car…. and now, 4yrs2months & 29k miles on… I don’t think i want to know.:)
  • Like
Reactions: 2
I mistakenly filled my gas tank up with E85 this morning. I am uncertain if I should drive the car or have it towed to get the gas tank flushed and new 91 gas put in. It is a 2019 Q4 Giuliani. I am at the gas station and uncertain what to do.
Better safe than sorry !!’
Could of resulted in all sorts of engine warning lights
As we all know Alfas are extremely
Temperamental on oils and fluids
I’d certainly play it safe
“Bet you won’t do it again”🤭
I did the same thing accidentally to my 2018 Giulia with E85, all I seen was octane I didn't see the other numbers and ran it through the system before realizing something was wrong after the engine service light came on although the car still runs does anybody have any suggestions?
Giuliani??? Gotta love autocomplete.
I preferred the 1996 Giuliani.
21 - 40 of 48 Posts
Top