E85 or regular gas?

[iboughtatahoe23]

I’ve always used e85 on my 2014. I read it can wear out the fuel system components. But I save a lot of money with e85 I feel like it’s $2 a gallon in my area.

 

[swathdiver]

I’ve always used e85 on my 2014. I read it can wear out the fuel system components. But I save a lot of money with e85 I feel like it’s $2 a gallon in my area.

Fake news. It keeps the system cleaner.

 

[Marky Dissod]

I’ve always used e85 on my 2014. I read it can wear out the fuel system components.

Pre-2000 vehicles with fuel systems built prior to ethanol in gasoline might've had that problem.
You need newer reading material.

I save a lot of money with e85 I feel like it’s $2 a gallon in my area.

fueleconomy.gov's opinion:

Ethanol

Ethanol is a renewable, domestically produced alcohol fuel that can help reduce oil dependence and emissions.

www.fueleconomy.gov

E85 (Flex Fuel)
E85 contains 51% to 83% ethanol, depending on geography and season.
Summer blends tend to have more ethanol, while winter blends have less.4

MPG.
Due to ethanol's lower energy content, FFVs operating on E85 get roughly 15% to 27% fewer miles per gallon than when operating on regular gasoline,
depending on the ethanol content. Regular gasoline typically contains about 10% ethanol.5

If E85 costs at least 15% less than gasoline in your area (where is that?),
you're likely getting good bang for your buck.
If I was lucky enough to find E85 in NYC under $2.559 a gallon, I'd run E85, instead of 87 @ 2.999 a gallon.

 

[Marky Dissod]

Hopefully you'll find this calculator helpful:

GasPumpr - Is Ethanol Worth It?

Compare ethanol gas to determine best value to purchase. For E85 Flex Fuel, E15, and E10 gasoline.

gaspumpr.com

Give it the price of gasoline in your area (don't forget the last 9), it'll spit out ethanol price targets.

(Note that when it says higher octane will not improve MpG, that page ignores pcm / ecm tuning.)

 

[swathdiver]

There are other reasons to run E85 that exclude the cost, like cleaning the injectors and that the motors love what is essentially cheap race gas. Mine makes about 10 horsepower more on E85 compared with 93 but also runs smoother, cooler, etc.

 

[Marky Dissod]

There are other reasons to run E85 that exclude the cost, like cleaning the injectors,
and that the motors love what is essentially cheap race gas.
Mine makes about 10 horsepower more on E85 compared with 93 but also runs smoother, cooler, etc.

Although I'm a pessimist, and do not expect to see any of the following, I'll be happy to be proven wrong:

*Lifetime comparison of two otherwise identical engines' lives,
one operating on pure petrol / E0/G100 gasoline, one operating on E51-E83
but these days the more likely comparison would be E10/G90 gasoline vs E51-E83

Comparison would focus on 3 things:
Highway MpG vs metro/urban/city/ stop'n'go MpG
Used motor oil analysis every oil change, which should happen every 4000 miles
Engine teardown after at least 200,000 miles, or when engine fails

Anyone who says the above is not going to happen, won't surprise me.

 

[swathdiver]

Although I'm a pessimist, and do not expect to see any of the following, I'll be happy to be proven wrong:

*Lifetime comparison of two otherwise identical engines' lives,
one operating on pure petrol / E0/G100 gasoline, one operating on E51-E83
but these days the more likely comparison would be E10/G90 gasoline vs E51-E83

Comparison would focus on 3 things:
Highway MpG vs metro/urban/city/ stop'n'go MpG
Used motor oil analysis every oil change, which should happen every 4000 miles
Engine teardown after at least 200,000 miles, or when engine fails

Anyone who says the above is not going to happen, won't surprise me.

I've done similar data collection and analysis with my Yukon XL since 2017 including oil analysis.

 

[Marky Dissod]

@swathdiver, IFF you were to use either gasoline or e85 for an entire oil change duration,
do you think you'd be able to lie to your motor oil analyst -
say you used e85 when you actually used gasoline, or vice versa -
and get away with it? Or do you think your oil analyst would detect the difference?

Motor oil is diluted by whatever fuel sneaks past the piston rings -
and some small amount of fuel ALWAYS manages to do so.
Theory: the more ethanol the engine burns, the more often oil should be changed ... ?

(Can catch can users tell the difference between using gasoline vs using e85?)

 

[swathdiver]

@swathdiver, IFF you were to use either gasoline or e85 for an entire oil change duration,
do you think you'd be able to lie to your motor oil analyst -
say you used e85 when you actually used gasoline, or vice versa -
and get away with it? Or do you think your oil analyst would detect the difference?

Motor oil is diluted by whatever fuel sneaks past the piston rings -
and some small amount of fuel ALWAYS manages to do so.
Theory: the more ethanol the engine burns, the more often oil should be changed ... ?

(Can catch can users tell the difference between using gasoline vs using e85?)

If they look for it I guess. They've never asked or said anything about it.

As you can see from my oil analysis', there isn't much fuel in the oil. Gas gets hot and evaporates, not sure why you would think it a problem, or E85 instead of gasoline. My truck has burned about two thousand gallons of E85 since 2017 what kind of damage am I supposed to have?

 

[Marky Dissod]

If they look for it I guess. They've never asked or said anything about it.

As you can see from my oil analysis, there isn't much fuel in the oil.
Gas gets hot and evaporates, not sure why you would think it's a problem, or E85 instead of gasoline.
My truck has burned about two thousand gallons of E85 since 2017 what kind of damage am I supposed to have?

Didn't say it's a problem, it's just a fact.
Imagine a (better) world where engine material wear was zero-point-zero. What reasons would there still be left to change the motor oil?
The admittedly very small amount of fuel that sneaks past the piston rings does slowly dilute motor oil.

As a rule of thumb, the better an engine's lifetime fuel economy,
the further apart the oil changes can be spaced.
(Yes, MpG - or GpM anywhere else - can be used as a very crude Oil Life Monitor.)

This is one of the reasons why catch cans are a wise investment,
even for engines that don't burn any oil (yet).
The best of them separate PCV vapors into (heavier) motor oil that settles in the can,
and (lighter) fuel that continues into the combustion chamber.

Was not suggesting that any engine suffers damage from burning E85.
Nor would I suggest that any engine suffers damage from burning petrol
(although higher octane fuel does have more upper cylinder lubricants than 'regular').

(Turbodiesel engines are experimenting with gapless 2nd rings; they've shown to improve BSFC.)
...
Final reason left to change motor oil, is that the engine's moving parts do wear motor oil down over time.

 

[swathdiver]

The admittedly very small amount of fuel that sneaks past the piston rings does slowly dilute motor oil.

What happens to the oil after it gets hot and the fuel evaporates? Is the oil no longer diluted?

I've never paid attention to the numbers of my oil analysis, it appears that the oil starts out at 11.8/67 and when tested at the end of the oil change is about 10/59. I don't know if that's good or not, but the motor doesn't rattle and got better mileage and the oil usage basically stopped after switching over to ACDelco and Quaker State from M1.

My 5.3 will hit 212K in a few days, still no catch can on it or any of my trucks. She's completely stock save for the BlackBear tune and Magnaflow cats and y-pipe and makes an average of 325 rear wheel horsepower through the traps in the 1/4 mile.

 

[Marky Dissod]

What happens to the oil after it gets hot and the fuel evaporates? Is the oil no longer diluted?

Ask your motor oil analyst. Once fuel gets into motor oil, it doesn't evaporate as easily as it would out in the open.

I've never paid attention to the numbers of my oil analysis, it appears that the oil starts out at 11.8/67 and when tested at the end of the oil change is about 10/59.

I'll go so far as to say that I don't know what those numbers mean. What units do those numbers measure?
It's as if I said I'm '3.8333'.

... oil usage basically stopped after switching over to ACDelco and Quaker State from M1.

Most people don't realize that the OTHER thing you just said, is 'I change my oil often enough'.
If anyone extends their oil change interval far enough, even with the 'best' motor oil, bet it'll use up some of it.
Partially because normal engine movements do physically wear down motor oil,
partially because motor oil gets diluted by fuel over time.
Obviously the krappyer the motor oil, the more susceptible it is to oil consumption.

 

[swathdiver]

Ask your motor oil analyst. Once fuel gets into motor oil, it doesn't evaporate as easily as it would out in the open.I'll go so far as to say that I don't know what those numbers mean. What units do those numbers measure?
It's as if I said I'm '3.8333'.Most people don't realize that the OTHER thing you just said, is 'I change my oil often enough'.
If anyone extends their oil change interval far enough, even with the 'best' motor oil, bet it'll use up some of it.
Partially because normal engine movements do physically wear down motor oil,
partially because motor oil gets diluted by fuel over time.
Obviously the krappyer the motor oil, the more susceptible it is to oil consumption.

Well, I was asking you because you are saying that fuel is diluting our oil and I am trying to understand how.

I think those numbers correspond to ASTM D445 viscosity numbers.

 

[Marky Dissod]

Well, I was asking you because you are saying that fuel is diluting our oil and I am trying to understand how.

Not all the injected fuel is burned. Before some of it escapes during the exhaust pulse,
some of it sneaks past the rings during the compression and power strokes.
I'm no Lake Speed Jr. Between me and him, there are plenty qualified to explain the details better than I.

 

[dwinters14]

This went off topic, but to answer the E85 vs Regular Gas... E85 hands down. I have used it now for over 3 years consecutively and on a GMT800 and GMT900. The trucks are way peppier, smoother, and smell better. I haven't lost a significant amount of MPG in the process either. I bought my current truck with an average of 14mpg's from the previous owner and it's dropped to 13.5mpg. I almost exclusively drive on the street in stop and go traffic.

Regular gas here is $4.19 + and E85 for me is $2.59. 38% price difference and slightly worse fuel economy but everything else as an advantage? No brainer.

 

[Fless]

Oil diluted with fuel can affect fuel trims and the fuel vapors can cause the computer to take away metered gas (so, negative fuel trims). Something to watch for after having a rich condition for a while. Fuel trims can tell a lot about what's going on inside...

 

[Marky Dissod]

Regular gas here is $4.19 + and E85 for me is $2.59.
38% price difference and slightly worse fuel economy but everything else as an advantage? No brainer.

In your case the price maths work.

 

[Marky Dissod]

Oil diluted with fuel can affect fuel trims and the fuel vapors can cause the computer to take away metered gas (so, negative fuel trims).
Something to watch for after having a rich condition for a while. Fuel trims can tell a lot about what's going on inside ...

Yes, this is absolutely true, but I was speaking on a much smaller scale.
Fuel vapor that makes it past the piston rings into the crankcase, hopefully,
get recuperated by the PCV system, although this is the other source of oil burning as well.
Catch can only helps by separating oil vapors from fuel vapors.

 

[Fless]

In your case the price maths work.

The math works even better if you're comparing mid-grade or premium, for the performance difference.

 

[Marky Dissod]

Think it depends on local corn prices. For me, e85 is too expensive in NYC, but the price is right in Long Island.