Rebel MPG - unleaded vs mid grade

[Str8Cracker]

My Rebel now has just over 14,000 miles on it, so it’s more than broken in. Just returned from a long road trip from the Chicago area to Louisville and then to Pigeon Forge and back. Total distance was about 650 miles each way and no matter where I was on the map, I always averaged about 1mpg better with unleaded over mid grade. 18.5 with unleaded and 17.5 with mid grade. Not complaining about the mpg, as I was doing about 75 most of the drive. I just figured mid grade would produce better mpg. Maybe I’m wrong?

 

[Ellisstrong]

I’m assuming the unleaded you speak of is regular 87?

 

[Zeronet]

My Rebel know has just over 14,000 miles on it, so it’s more than broken in. Just returned from a long road trip from the Chicago area to Louisville and than to Pigeon Forge and back. Total distance was about 650 miles each way and no matter where I was on the map, I always averaged about 1mpg better with unleaded over mid grade. 17.5 with unleaded and 18.5 with mid grade. Not complaining about the mpg, as I was doing about 75 most of the drive. I just figured mid grade would produce better mpg. Maybe I’m wrong?

Not understanding your post. You said you get better mileage with 87 (17.5) than with 89 (18.5)? But it 17.5 is worse than 18.5, right? I’m missing something.

 

[Str8Cracker]

Sorry for the confusion and yes, regular for us here is 87 and mid grade is 89. 87 consistently got about 1mpg better than 89. This was via hand calculation too, not the computer.

 

[Tommy R]

I didn't notice any difference between 87 and 89 other than the hit to the wallet, but I'd love to know how you got that kind of economy doing 75 mph! I'd be getting 14-15 at best. I'm at 9500 miles so it should be "broken in" I'd say.

 

[JHRebel]

I haven't noticed much if any difference either....I do mostly use 87, every once in a while Ill pump in the 89...There doesn't seem to be a conceivable way that even if the 89 added a little it would make up for the price difference in my area, Im at 7,000 miles and change, and hover around 18 on the highway drives/trips, traveling between 65 and 80mph.

 

[YawnY]

On the highway at 100 km/h I'm getting between 10-12 L/100 that's 23.5 mpg to 19.6 mpg using 87 octane. I see no need to use 89

 

[Str8Cracker]

Thanks for the input guys! Most of my driving is in town, so my average tank is usually more around your 14-15 Tommy R. I’m thinking I have no need to run 89 if I achieve better MPG with 87 and don’t notice a power difference.

 

[silver billet]

I doubt you get better MPG on 87. Not saying you didn't get those numbers, but wind or driving speed/style or slight elevation or differing ethanol content etc probably gave you those numbers and not the octane.

 

[Neokane]

Is there any difference in ethanol? Living in the midwest, regular is ethanol. Mid grade and up is often ethanol free.

I've always found ethanol free fuel to give slightly better mpg than ethanol.

 

[RAMpage]

On the highway at 100 km/h I'm getting between 10-12 L/100 that's 23.5 mpg to 19.6 mpg using 87 octane. I see no need to use 89

Get about that myself since it’s fairly flat around here. Odd time it dips down to 9 but that’s rare (tailwind I’m guessing). I’m quite happy with 10-12L/100km. That’s what my last EcoDiesel would get on the highway.

 

[Gardner]

Brings up a question...what is the recommended fuel octane? I haven't found it anywhere.

In my area, I have a station that sells 89 octane for same $ as regular 87. So I've been using the 89, why not?
I did find a gas receipt where the dealer put in "regular" 87 before I bought. Didn't notice any pinging with the regular.

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2019 Bighorn Crew cab, 4x4, 3.21 rear and the usual standard stuff. Build date was 11/18.
Options: Delmonico Red, Cloth buckets, level 2 equip package (8.4 in screen and other stuff).
5.7 Hemi, Ram SS running boards and also, an after market American tonneau fabric cover.

 

[Diamondback]

Brings up a question...what is the recommended fuel octane? I haven't found it anywhere.

In my area, I have a station that sells 89 octane for same $ as regular 87. So I've been using the 89, why not?
I did find a gas receipt where the dealer put in "regular" 87 before I bought. Didn't notice any pinging with the regular.

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Your owner's manual says this :

 

[Gardner]

Oops, a RTFM reply.
I'm tempted to say "we're guys, we don't need no f'ing manual"
Kidding - thanks.

 

[CaptainCJ35]

Car and Driver has a recent article that seems topical:

Is Premium Gas Worth It? We Test High Octane on 4 Popular Vehicles

We tested higher octane fuel than manufacturers require on the Honda CR-V, BMW M5, Ford F-150, and Dodge Charger to see if it impacted acceleration or MPG.

www.caranddriver.com

A Dodge Charger with 5.7 Hemi is one of 4 vehicles they test for differences in performance when using different Octane gasoline. I think their results back up the general conclusions contained in this thread, and my own as well. There are differences, though minimal, and any cost vs mpg vs performance benefit depends greatly on circumstance. 89 is "optimal" for the RAM, but 87 is hardly going to be a hindrance. The rest is personal preference.

 

[CaptainCJ35]

Now that I think about it though... octane rating for towing would be an interesting test. More stress on the engine, for longer periods, may swing the octane argument more towards the higher rating.

 

[TheMadDutchDude]

My truck seems happiest on 89 or 93, and I get 19 to 21 MPG at 75 to 80 on the highway. My ‘17 managed 22 on the highway at the same speeds.

 

[mac1983620]

On the highway at 100 km/h I'm getting between 10-12 L/100 that's 23.5 mpg to 19.6 mpg using 87 octane. I see no need to use 89

Would really like to see that.

 

[YawnY]

Would really like to see that.

Like you want pictures, or you want your truck to do that?