To fill up with E-15 (88) or 87-89 Octane

[James3201]

So here is a question that I have seen many answers to, but not fit the bill. I have been wondering about E-15 fuel that the owners manual talks about, which is 88 Octane. According to the owners manual: "Non-Flex Fuel Vehicles (FFV) are compatible with gasoline containing up to 15% ethanol (E-15). Use of gasoline with higher ethanol content may void the New Vehicle Limited Warranty." According to FCA filling up with E-15 is ok, as long as you do not go over that 15% ethanol to gas mixture.
I am also old enough to know about gasoline that didn't have ethanol in it and the advantages and disadvantages of it, and what ethanol is doing to the engine on newer vehicles. I have heard that ethanol doesn't allow the same cooling as traditional gas, nor the lubricating properties. I am curious to see what everyone thinks, or is using. I want to maximize my fuel economy in my 5.7L Hemi, and am torn between Ethanol Free ($3.15 a gallon here in NC, where you can find it), and just sticking with the 87.

 

[Neurobit]

So here is a question that I have seen many answers to, but not fit the bill. I have been wondering about E-15 fuel that the owners manual talks about, which is 88 Octane. According to the owners manual: "Non-Flex Fuel Vehicles (FFV) are compatible with gasoline containing up to 15% ethanol (E-15). Use of gasoline with higher ethanol content may void the New Vehicle Limited Warranty." According to FCA filling up with E-15 is ok, as long as you do not go over that 15% ethanol to gas mixture.
I am also old enough to know about gasoline that didn't have ethanol in it and the advantages and disadvantages of it, and what ethanol is doing to the engine on newer vehicles. I have heard that ethanol doesn't allow the same cooling as traditional gas, nor the lubricating properties. I am curious to see what everyone thinks, or is using. I want to maximize my fuel economy in my 5.7L Hemi, and am torn between Ethanol Free ($3.15 a gallon here in NC, where you can find it), and just sticking with the 87.

15% is pushing it, in my opinion. I would stick with something lower if you can find it. Ethanol is not good for the engine, so the lower the better.
I use 89 which seems to work fine. I could do 87, but 89 is not much of a price difference.

Cheers,

 

[knightro84]

I've run ethanol free 89 through my last five tanks, and I'm not seeing fuel savings that outweigh the price difference over E10 89. At the station near my office where I typically fill up, the ethanol free 89 is usually about 15% more expensive than regular 89, but I haven't seen a 15% increase in MPG under similar driving conditions, it's really only been about a 5-6% increase. I can't tell any difference in how the truck runs on E10 89 vs ethanol free 89.

 

[JJRamTX]

To be safe I don't think I would go with anything over 10% ethanol. Sometimes you don't have a choice which is why I keep a fuel treatment bottle to add a bit when 15% is what your stuck with...

 

[RedRocketZ28]

Like you stated, the manual says 15% is fine. I have not personally ran it yet in my truck but around here our regular 87 that I run has up to 10% ethanol. I am going to give E15 a shot at some point to see if I notice much MPG decrease.

Ethanol cools better than gasoline. It pulls more heat out of the intake charge. Also, since it has more octane you can run more aggressive timing before running into detonation issues. Hence the reason I run it in my turbo Camaro instead of regular gasoline.

Saying ethanol is not good for the engine is completely false. I have ran E85 in my turbo Camaro for 6 years, driven it all over, raced it, let it sit dormant for months at a time, and I have never had an ethanol related issue. Not to mention, it helped my stock bottom end 6.0L survive over 700 rwhp for almost 5 years.

There are so many myths about ethanol, and uneducated non-ethanol users out there think it's going to ruin your fuel lines, engine, etc.

 

[danielle2019]

I’m a non-ethanol user. It’s not a matter of being uneducated - although one could be forgiven for being a bit confused by the various opinions offered as fact, online and elsewhere. My own empirical data suggests my vehicles have run better on pure 89 gasoline, so I run with it

 

[MTRHEAD]

I run 10% in mine but i watch where i buy it. There is one chain of stations in my area that a local ford dealer service dept checked because of poor fuel mileage complaints they had. They were advertised of having 10% but test's showed 22%.

 

[danielle2019]

I run 10% in mine but i watch where i buy it. There is one chain of stations in my area that a local ford dealer service dept checked because of poor fuel mileage complaints they had. They were advertised of having 10% but test's showed 22%.

Willing to bet that happens a lot.

 

[slimchance]

i ran E 15 in our Tundra 5.7s for most of 3 yrs with NO problems ... fuel mpg always HC slightly higher and cost per gal was 5 cents cheaper ... now my wife and i each have 2019 Rams and continue to run E 15 ... look at our Fuelly results .. i see many on these forums that insist on 89 gas and they generally have lower mpg figures, does that mean they drive more aggressively than us

 

[James3201]

Like you stated, the manual says 15% is fine. I have not personally ran it yet in my truck but around here our regular 87 that I run has up to 10% ethanol. I am going to give E15 a shot at some point to see if I notice much MPG decrease.

Ethanol cools better than gasoline. It pulls more heat out of the intake charge. Also, since it has more octane you can run more aggressive timing before running into detonation issues. Hence the reason I run it in my turbo Camaro instead of regular gasoline.

Saying ethanol is not good for the engine is completely false. I have ran E85 in my turbo Camaro for 6 years, driven it all over, raced it, let it sit dormant for months at a time, and I have never had an ethanol related issue. Not to mention, it helped my stock bottom end 6.0L survive over 700 rwhp for almost 5 years.

There are so many myths about ethanol, and uneducated non-ethanol users out there think it's going to ruin your fuel lines, engine, etc.

About 3 Rams ago I had a V6 version that was also E85 compliant and that's all I ran while I was in PA, and ended up with better gas mileage out of it than I did regular 87, this was also years ago when E85 was new to the area, and only a few stations carried it. My wife owns a 2014 Durango that is E85 capable, and that's all we run in it as well, and haven't had 1 issue! In fact we will hunt it out before putting in regular 87. The Durango only has 36,000 miles on it, and it runs like a new car still. The dealership tried selling her a fuel cleaner package one time, and I called up there and said we didn't need it, and they tried to say well running E85 all the time isn't good for it, I told them to look at the fuel injectors and tell me what they thought, they havent tried to sell it to us again becasue of how great they looked!

 

[James3201]

I believe I will let this tank empty out and fill it with E-15 (Not E-85!) and see if I can notice a difference in gas mileage and also performance and go from there.

 

[RedRocketZ28]

About 3 Rams ago I had a V6 version that was also E85 compliant and that's all I ran while I was in PA, and ended up with better gas mileage out of it than I did regular 87, this was also years ago when E85 was new to the area, and only a few stations carried it. My wife owns a 2014 Durango that is E85 capable, and that's all we run in it as well, and haven't had 1 issue! In fact we will hunt it out before putting in regular 87. The Durango only has 36,000 miles on it, and it runs like a new car still. The dealership tried selling her a fuel cleaner package one time, and I called up there and said we didn't need it, and they tried to say well running E85 all the time isn't good for it, I told them to look at the fuel injectors and tell me what they thought, they havent tried to sell it to us again becasue of how great they looked!

Definitely not normal for gas mileage to increase with E85. My buddy runs E85 in his Tahoe every once in awhile and his MPG drops significantly.

The only issues with E85 I have seen in the performance world is some injectors get a black goo in them from either the E85 sitting in them or something in the fuel lines they are using. I have had zero issues though and it definitely makes the pistons a lot cleaner as I've noticed when tearing down my old engine.

I believe I will let this tank empty out and fill it with E-85 and see if I can notice a difference in gas mileage and also performance and go from there.

Don't put E85 in your Ram. You can run up to E15 and that's it.

I filled up yesterday with 88 E15. Going to run it through it and see if I notice much of a MPG swing. If not, I will continue to run it as it's 5 cents cheaper than the regular 87 with 10% ethanol.

 

[James3201]

Definitely not normal for gas mileage to increase with E85. My buddy runs E85 in his Tahoe every once in awhile and his MPG drops significantly.

The only issues with E85 I have seen in the performance world is some injectors get a black goo in them from either the E85 sitting in them or something in the fuel lines they are using. I have had zero issues though and it definitely makes the pistons a lot cleaner as I've noticed when tearing down my old engine.



Don't put E85 in your Ram. You can run up to E15 and that's it.

I filled up yesterday with 88 E15. Going to run it through it and see if I notice much of a MPG swing. If not, I will continue to run it as it's 5 cents cheaper than the regular 87 with 10% ethanol.

Yeah, I missed typed before I meant to say E-15, NOT E-85! I'm about at 1/4 tank now, so a little longer to go before I try the E-15, and see if I can notice the difference with it. I will post again once I fill up with it, and then do some driving and see if I can measure the results.

 

[rhill]

If you ever look at EPA ratings for E85 use, you will notice that mpg drops 25 to 30% over standard gas. Only logical that E15 will get worse mileage than E10.

 

[slimchance]

may be "logical that E15 will get worse mileage than E10 " BUT does not work that way for me ... i have never used E 85 but do use E 15 as often as possible for the last 3 - 4 yrs

 

[Fidomac]

I run 10% in mine but i watch where i buy it. There is one chain of stations in my area that a local ford dealer service dept checked because of poor fuel mileage complaints they had. They were advertised of having 10% but test's showed 22%.

If you have QuikTrip in your area they tend to have very good gasoline that is guaranteed

 

[SpeedyV]

If you have QuikTrip in your area they tend to have very good gasoline that is guaranteed

Agreed. QT offers Top Tier gas at reasonable prices.