Should I try running E85? Or stick with unleaded.

[swathdiver]

i live in NJ, theres not one station that sells e85. pretty dumb being Long Island is full of corn and it has to travel through NJ to get to LI lol

Well, I found one! A Power Gas in East Orange and they sure are proud of E85 @ $2.53 a gallon.

 

[Scottydoggs]

id be driving there, fill it up, then need another tank when i got home. ( not really that far away) but to far to be worth it. the key to e85 is it needs to be local.

thats a start tho. we grow the corn here, dont see why they dont sell it all over here, unless they need a new tank installed for it, then i could see none getting sold.

 

[Matahoe]

The issue with ethanol is not that it causes deposits...it actually burns very clean. The issue is that it attracts water. That in effect can cause corrosion of fuel components and buildup of deposits on pistons and valves.

 

[swathdiver]

...the key to e85 is it needs to be local.

There are other stations listed on other websites, places on Gas Buddy drop off if nobody reports fuel prices in 48 hours. Then you have areas where people just won't report E85 prices at a particular station. Look for yellow gas handles. I agree, it would be quite difficult to plan a trip to Texas from Florida and expect to run E85 all the way there and back. There's too few stations along the way and of course the distance between stops is less. Being diabetic, that isn't a problem!

The issue with ethanol is not that it causes deposits...it actually burns very clean. The issue is that it attracts water. That in effect can cause corrosion of fuel components and buildup of deposits on pistons and valves.

Let's explore this water angle. How so? Will my tank have several gallons of water in it after a time? After 18 months of on and off use I don't think that's the case. As for build up on the pistons and valves, Maybe I should stick a bore camera down a spark plug hole and have a look?

 

[SnowDrifter]

There are other stations listed on other websites, places on Gas Buddy drop off if nobody reports fuel prices in 48 hours. Then you have areas where people just won't report E85 prices at a particular station. Look for yellow gas handles. I agree, it would be quite difficult to plan a trip to Texas from Florida and expect to run E85 all the way there and back. There's too few stations along the way and of course the distance between stops is less. Being diabetic, that isn't a problem!



Let's explore this water angle. How so? Will my tank have several gallons of water in it after a time? After 18 months of on and off use I don't think that's the case. As for build up on the pistons and valves, Maybe I should stick a bore camera down a spark plug hole and have a look?

Edit: Researched response posted below

 

[adriver]

Where can I find my RPO codes? Are they still in the glovebox like they were back in the day? My gas cap is currently black but i have no idea if its original or not.

Your VIN and RPO code. The engine's look identical between the LM7 and L59 but you will have much larger fuel injectors and the rail might be different. I'm not familiar enough to tell. Also, yours has an alcohol content sensor and your original gas cap was yellow. If you have a good scan tool or fancy OBD adapter, you can view the alcohol content whereas a regular truck will not have that feature.

VIN # 8th digit
V 4.8
T 5.3
Z 5.3 FF
U 6.0 LQ4
N 6.0 LQ9

 

[chrmbly]

I never tried it, but I’m tempted in my 2014 Sierra. I always thought the lower mpg made it a negligible cost savings

 

[SnowDrifter]

I never tried it, but I’m tempted in my 2014 Sierra. I always thought the lower mpg made it a negligible cost savings

It depends on the cost of E85. Sometimes it's a saving, sometimes its not.

However, independent of cost, it might be worth running a few tanks of E85 back to back every few years. Ethanol is extremely clean burning and does a great job of cleaning up carbon left behind by E10 fuels.

This is after a 3k mile run of e85. Clean as a whistle!

 

[SnowDrifter]

There are other stations listed on other websites, places on Gas Buddy drop off if nobody reports fuel prices in 48 hours. Then you have areas where people just won't report E85 prices at a particular station. Look for yellow gas handles. I agree, it would be quite difficult to plan a trip to Texas from Florida and expect to run E85 all the way there and back. There's too few stations along the way and of course the distance between stops is less. Being diabetic, that isn't a problem!



Let's explore this water angle. How so? Will my tank have several gallons of water in it after a time? After 18 months of on and off use I don't think that's the case. As for build up on the pistons and valves, Maybe I should stick a bore camera down a spark plug hole and have a look?

I did some more reading into this. Found a head after a year and a half of E85. Definitely seems corrosion is a valid concern. Also saw some dyno videos on youtube where E85 cooled the intake charge so much the supercharger built condensation on the outside

And here's from a block off a different vehicle. Seems to support the corrosion issue in a DD scenario.

I also found this video, which seems to support the clean burning nature of E85. The engines were ran for 500 hours, but I suspect this was a continuous run and won't show the affect of thermal cycles like shown in the head above

And this neat little comparison where ethanol and gasoline were run, then wear numbers compared

Full paper here: https://www.sciencedirect.com/science/article/pii/S0043164818300450





So, my conclusions are this: Run a few tank fulls every couple years to take advantage of the cleaning abilities of E85. However, due to an increase in wear and corrosion concerns both with the engine internals and metallic parts of the fuel system, I wouldn't find it suitable for daily use where long term vehicle reliability is a concern.

 

[SnowDrifter]

duplicate post please ignore

 

[swathdiver]

I've been out of engine building for a few decades but those center and right side pictures don't look a whole lot different than my Buick blocks after 100K+ miles if memory serves.

 

[SnowDrifter]

That was after 450h of run-time. Equivalent to 10-12k miles of normal driving.

I think the info on cylinder wall wear tells much more of the story

 

[swathdiver]

Well here's my take Chris. Since October of last year, my truck has used 1,074 gallons of fuel. 586 gallons of that was E85. My engine still does not burn a drop of oil between changes unless I regularly spin the engine past 3,000-3,500 rpms. About 600 miles were while towing 2,500 to 6,000 pounds while burning E85.

I would think that if my rings were worn down that much from E85 that my engine would burn oil. It's usually dirty oil that contributes to rings going bad.

In October I over-filled the motor with oil a little bit and did not get to correct the mistake and then forgot about it until just now. When I get home tonight and let her cool off some, I'll check it and see if any burned off.

 

[SnowDrifter]

I'm not arguing appearance vs. performance. To be honest I'm not arguing anything LOL. Just having an intellectual discussion about the pros and cons of different fuel types.

I couldn't find anything about a difference in ring wear, just that paper on bore wear. And as it is, wear is cumulative. An uptick in wear doesn't mean worn out, only a reduced lifespan. How much, however? I couldn't tell you. Information is just that... It's... Information. What you do with it depends on your scenario.

What's appropriate to use depends entirely on your usage case. If you don't keep a vehicle long term (less than ~175k), minor variations like that are of little to no concern. If you're like me and like to keep things long term, then it's appropriate to dig into discussions like this a little more.


I was thinking about this a little more though. The main concern of high ethanol content fuels seems to revolve around moisture and its effects on surfaces it comes into contact with - anything ferrous. Makes me wonder if we'd see any stainless-type alloys should this type of fuel become the norm.

 

[swathdiver]

I'm not arguing appearance vs. performance. To be honest I'm not arguing anything LOL. Just having an intellectual discussion about the pros and cons of different fuel types.

I couldn't find anything about a difference in ring wear, just that paper on bore wear. And as it is, wear is cumulative. An uptick in wear doesn't mean worn out, only a reduced lifespan. How much, however? I couldn't tell you. Information is just that... It's... Information. What you do with it depends on your scenario.

What's appropriate to use depends entirely on your usage case. If you don't keep a vehicle long term (less than ~175k), minor variations like that are of little to no concern. If you're like me and like to keep things long term, then it's appropriate to dig into discussions like this a little more.


I was thinking about this a little more though. The main concern of high ethanol content fuels seems to revolve around moisture and its effects on surfaces it comes into contact with - anything ferrous. Makes me wonder if we'd see any stainless-type alloys should this type of fuel become the norm.

I understand and talking about it is good. I was under the impression that anything not plastic is stainless steel as in the fuel rail with regards anything that comes in contact with Fuel until it enters the combustion chambers.

 

[SnowDrifter]

You'd think, but unfortunately that's not the case.

Fuel pump is mostly plastic, but the motor has to be ferrous by principle of operation.

Filter IIRC is just a screen, but that's plastic if you have an '05+ and its built in with the fuel pump.

Fuel lines are a mix of plastic and not sure what the metal is. I've seen it rust so perhaps galvanized steel?

Rail is stainless

Injectors are iron/steel. Spring steel, plus the plunger(or whatever the technical term is) has to be magnetic so that's iron/steel. Nozzles are steel.

Head is aluminum. Valves can be made of a variety of things. Steel/nichrome/stainless/titanium. Our vehicles use solid steel - no sodium filled shenanigans there.

Valve seats - honestly I'm not sure.

Pistons are aluminum. No worries there

Rings are molybdenum coated spring steel IIRC.

Cylinder liners (or block) are iron.

 

[09 L9H]

Mine is also always in 4auto. I thought thats where it was suppossed to stay. Do you get better mileage with it off? When i hit the top button it says stabilitrack disabled. I thought i was suppossed to be driving around in that mode but i didnt wanna damage anything.

There's no mechanical harm done when you drive around in 4A. From what I understand it just keeps your front axle locked and ready to engage. I have seen about 1 mpg improvement in highway driving with it off. Also not sure what "top button" you're referring to, the only way I know to disable stabilitrak is to press and hold the TC button for 10 seconds or so.

It'll never knock on E85! Why do you not make use of the 6-speed?

It'll also never knock on 91 or 93. Honestly, when I ran 87 I never noticed a knock or even pinging. So there's that haha. Also not sure what you mean by not making use of the 6spd.

 

[swathdiver]

There's no mechanical harm done when you drive around in 4A. From what I understand it just keeps your front axle locked and ready to engage. I have seen about 1 mpg improvement in highway driving with it off. Also not sure what "top button" you're referring to, the only way I know to disable stabilitrak is to press and hold the TC button for 10 seconds or so.

It'll also never knock on 91 or 93. Honestly, when I ran 87 I never noticed a knock or even pinging. So there's that haha. Also not sure what you mean by not making use of the 6spd.

I misunderstood what you wrote. I thought 4A meant you drove around in 4th gear.

 

[09 L9H]

I misunderstood what you wrote. I thought 4A meant you drove around in 4th gear.

Lol, no. That would make me a mega idiot

 

[swathdiver]

You'd think, but unfortunately that's not the case.

Fuel pump is mostly plastic...

Let me pose this question. Does the material matter if the item is always submerged or covered in fuel?

 

[Scottydoggs]

T
It'll also never knock on 91 or 93. Honestly, when I ran 87 I never noticed a knock or even pinging. So there's that haha. Also not sure what you mean by not making use of the 6spd.

by knock we mean knock retard, you cant hear it, but your engine can suffer from it. when you get kr the pcm pulls timing, making your engine fall flat. so no knock is best. e85 has a 106 iirc octane rating or in that area. with that much you can run more timing then normal every time. (its like race fuel really) more timing, more power. to a certain point, then it becomes counterproductive.

kr is mostly a wot deal, wont see any unless your pounding on it.

when i bought my truck i saw up to 4 degrees KR while scanning it. i own a tuner so i fixed that, and still im able to run more then stock timing. i run 93 all the time.