Is it alright that I just put Premium fuel in my 2019 Ram 1500 Big Horn?

[Neurobit]

So stick with mid-grade? Is it a big deal that my first 33 gallons were regular?

You'll be fine. Just get mid grade going forward if you need peace of mind, but 87 did not hurt anything.
Lots of folks been running it w/o any ill effects. Manual recommends 89.

Cheers,

 

[zdeckich]

Octane is a measure of resistance to detonation. It would be fair to say that the higher the octane rating, the “harder” a fuel is to burn. It certainly doesn’t burn “easier”. The whole point of higher octane is to support higher compression ratios without premature detonation (i.e. “knocking”).

Octane rating - Wikipedia

en.m.wikipedia.org

Thank you, finally someone who understands.

 

[SD Rebel]

View attachment 33416

Which manual is this from, it's different than mine which doesn't mention premium fuel at all.

 

[devildodge]

Which manual is this from, it's different than mine which doesn't mention premium fuel at all.

It is from my HD manual.

 

[SD Rebel]

It is from my HD manual.

I just checked my manual, I found where it said the same thing, but only under the 3.6L V6. Under the 5.7L it doesn't make the same mention of using premium will result in the same performance of regular. It make sense, the 3.6L is designed specifically for 87, whereas the 5.7L for 89.

My only concern is that 91 doesn't revert down to 87 tune in the 5.7L, which makes no sense anyways. There is a reason why many of us use 91 over 89, because we use Costco gas, which is priced cheaper in premium over the regular gas at other stations. Also, Costco doesn't offer 89, only 87 or premium.

 

[Willwork4truck]

I just checked my manual, I found where it said the same thing, but only under the 3.6L V6. Under the 5.7L it doesn't make the same mention of using premium will result in the same performance of regular. It make sense, the 3.6L is designed specifically for 87, whereas the 5.7L for 89.

My only concern is that 91 doesn't revert down to 87 tune in the 5.7L, which makes no sense anyways. There is a reason why many of us use 91 over 89, because we use Costco gas, which is priced cheaper in premium over the regular gas at other stations. Also, Costco doesn't offer 89, only 87 or premium.

So mix the two. Thats what I do, or just use 87/88 as I see it.

 

[thabiiighomie]

I turned my truck on this evening to go grocery shopping. Put it in reverse and thought it was just me, then my girlfriend walk up to the truck from the house and asked if I was revving my engine. I roll down the window and the truck was sputtering/shaking. Lasted about a minute. No clue what that was about.

1,600 miles on the dash. 1/2 tank of fuel. Still mostly premium in the tank from last fill-up.

 

[HeliPilot]

FWIW, My truck has 13K miles and typically I run 89 Octane Mobil fuel from my local store. A couple of weeks ago, I put in Sam's Club 93 Octane. The next morning my truck started, then almost died before it finally surged out of very low RPM. It did this at every initial start of the day for the next week. Next fill up, I put in the Mob 89 Octane and truck starts smoothly again. Cannot explain it, but definitely not putting Sam's gas in again.

 

[J-Cooz]

I've run 87/89/91. I noticed actually worse mileage with 91. With 87/89 I don't notice any difference in power or economy. I run 89 most times but if I go to Costco I get 87.

 

[REBL 909]

My other vehicle takes premium and I had a mind lapse. I always use mid-grade, although it’s very first take (from dealership) was regular.

So, I currently have my 2020 Ram Rebel at a SECOND dealership because of a "Cylinder 2 Misfire". The first one insisted that I had diesel fuel in my tank. Wrong answer. Went to MY mechanic of over 20 years and he confirmed that it does NOT have diesel but just the "Octane Booster" that I added. So, I took it to an entirely different dealership who confirmed SOMETHING besides gasoline in it. When I explained to the them WHAT was in it they said that it's NOT DESIGNED for higher octane fuel. Everything I have read says that it minimizes pings and knocks which I have noticed for the past 15 years of using it. Any insight?

 

[UnloosedChewtoy]

So, I currently have my 2020 Ram Rebel at a SECOND dealership because of a "Cylinder 2 Misfire". The first one insisted that I had diesel fuel in my tank. Wrong answer. Went to MY mechanic of over 20 years and he confirmed that it does NOT have diesel but just the "Octane Booster" that I added. So, I took it to an entirely different dealership who confirmed SOMETHING besides gasoline in it. When I explained to the them WHAT was in it they said that it's NOT DESIGNED for higher octane fuel. Everything I have read says that it minimizes pings and knocks which I have noticed for the past 15 years of using it. Any insight?

They're looking for an easy way out, most likely. An excuse to blame you, the customer, rather than troubleshoot further. I'd probably look for another $tealership. Slightly higher octane fuel should not cause any misfires.
What additive "booster" did you use?

 

[Olive Green 5.7]

Side note - we can not run E85 in our 5.7L equipped trucks, right?

 

[Olive Green 5.7]

Update, I answered my own question:

 

[Timeless]

So, I currently have my 2020 Ram Rebel at a SECOND dealership because of a "Cylinder 2 Misfire". The first one insisted that I had diesel fuel in my tank. Wrong answer. Went to MY mechanic of over 20 years and he confirmed that it does NOT have diesel but just the "Octane Booster" that I added. So, I took it to an entirely different dealership who confirmed SOMETHING besides gasoline in it. When I explained to the them WHAT was in it they said that it's NOT DESIGNED for higher octane fuel. Everything I have read says that it minimizes pings and knocks which I have noticed for the past 15 years of using it. Any insight?

So the truck is designed to run any normal octan 87-93. However additives are not going to be covered if they can be found to be the problem. Not sure why you would bother with an octane booster as it works fine with 87 and is optimized for 89. 91-93 is overkill as the computer does not take advantage of the higher octane. That said, I do put 93 in it and then 87 on the next fill up and repeat the pattern as the 93 at Sams/Costco is typically less than the 89 at normal stations.

 

[RAM Patriot]

Side note - we can not run E85 in our 5.7L equipped trucks, right?

One US gallon of gasoline contains 114,000 BTU of energy; depending on the time of year, and depending on what is in the gasoline. It is getting harder to find gasoline's that does not contain 5 to 10% of Ethanol.

Ethanol is ethyl alcohol; the kind of alcohol in beverages; beer, whiskey, bourbon, vodka, ****tails, etc.. It takes one and a half US gallons of ethanol to equal the energy in one US gallon of gasoline; the reason... because ethanol only has 76,100 BTU's of energy per gallon.

Less energy means less miles per gallon. In 2007 George W. Bush made it possible for gas stations to sell Gasohol (E10) without labeling the pumps; in other words, you may not know alcohol is in the gas.

Ever wonder where your gas mileage went?

 

[Timeless]

One US gallon of gasoline contains 114,000 BTU of energy; depending on the time of year, and depending on what is in the gasoline. It is getting harder to find gasoline's that does not contain 5 to 10% of Ethanol.

Ethanol is ethyl alcohol; the kind of alcohol in beverages; beer, whiskey, bourbon, vodka, ****tails, etc.. It takes one and a half US gallons of ethanol to equal the energy in one US gallon of gasoline; the reason... because ethanol only has 76,100 BTU's of energy per gallon.

Less energy means less miles per gallon. In 2007 George W. Bush made it possible for gas stations to sell Gasohol (E10) without labeling the pumps; in other words, you may not know alcohol is in the gas.

Ever wonder where your gas mileage went?

While everything above is true I would be surprised if it amounted to more than .25-.5 miles per gallon difference if that.

 

[Jako]

While everything above is true I would be surprised if it amounted to more than .25-.5 miles per gallon difference if that.

If the correlation of BTUs and mpg is direct than 20 mpg with 100% gasoline would equate to 19.34 with 10% ethanol,
114,000 BTUs vs 110,210 BTUs. the loss per mpg depends on your mpg, so at 10 mpg the loss is .3+mpg, while it is .66 at 20 mpg. Alcohol also raises the octane.

 

[Scram1500]

I just remember being told that if I made that mistake with my Alfa Romeo, and put in low-grade, I should not start the engine and have the fuel siphoned lol

Assuming it would start in the first place lol

 

[RAM Patriot]

If the correlation of BTUs and mpg is direct than 20 mpg with 100% gasoline would equate to 19.34 with 10% ethanol,
114,000 BTUs vs 110,210 BTUs. the loss per mpg depends on your mpg, so at 10 mpg the loss is .3+mpg, while it is .66 at 20 mpg. Alcohol also raises the octane.

Gasoline's blended with Ethanol will lower MPG in most engines. The EPA says Fuel efficiency can decrease by 1.5% to 3%.

 

[Jako]

Gasoline's blended with Ethanol will lower MPG in most engines. The EPA says Fuel efficiency can decrease by 1.5% to 3%.

Based on just BTUs works out to 3.32%, no idea how or what is factored in by EPA.