Switching from 87 to 93 octane made a difference!

[kenthorkveen]

Curious if you see better MPG with 93 over 87?
Think I'm about ready to stop using 87 in my new Hemi.
12.0 -12.5 MPG around town with light foot most of the time.

I get at least 15 mpg around the city on 89.. but, I have a heavy foot!

 

[mikeru82]

Here's an interesting article from Car and Driver about this topic and the 5.7 specifically:

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

Testing between 87 and 93, they found identical 0-60 times but a 0.3 mpg improvement using 93. On the dyno, the 93 brought gains of 14 hp and 23 lb ft of torque. For a ~400 horsepower and ~400 lb ft engine, this is not worth the extra cost of fuel for me. This is "fine" to me.

Interesting that the difference between 93 octane and 87 octane, at least with the Hemi, can really only be seen on the dyno. In real world driving you won't be able to tell the difference, according to this article. Kind of echoes my experience with my 4th gen. I used 87 octane for 2 and a half years. And I never noticed it knock. It's likely that the fuel economy I mentioned above came from putting some miles on the engine, as I made the switch to 89 octane at right around 3500 miles iirc. Thanks for posting that article!

 

[IrishRED]

I did two or three tanks of 87 before I noticed that the manual said 89 was recommended. I usually fuel at BJ's Wholesale Club where I get a discount. There they only have 87 or 93. The 93 there is $.40/gallon more than the 87 but using that is still cheaper than buying 89 at any other gas station in the area! Since I made the switch, I noticed no knock or ping where I did occasionally have it before. Truck seems to have a little more "get up and go" now but I have not noticed any difference in mileage.

 

[OldMarine]

5.7 non e-torque, I ran 87 on my 4700 mile trip in August, pulling #6000 of travel trailer, including Black Hills...no pings, no trans problems....smooth as silk. Been running 87 ever since.

 

[Ranger482]

I did two or three tanks of 87 before I noticed that the manual said 89 was recommended. I usually fuel at BJ's Wholesale Club where I get a discount. There they only have 87 or 93. The 93 there is $.40/gallon more than the 87 but using that is still cheaper than buying 89 at any other gas station in the area! Since I made the switch, I noticed no knock or ping where I did occasionally have it before. Truck seems to have a little more "get up and go" now but I have not noticed any difference in mileage.

Same at the Costco pumps. I just "custom blend" to get to roughly 89 octane as I see no point in paying the additional $ for 93 only. Have to run the card twice, but not a big deal.

 

[Adrianp89]

Over 100k miles on 3 different 5.7s all on 87. Never one issue.

 

[LakesAZ]

I think I'm going with the Costco custom blend, except instead of running the card twice I will fill up at the 1/2 tank level every other time with 91. 91 is what we get here in Arizona. Having a 33 gallon tank makes this method work out.

 

[nicknik]

Looking at all these gas prices taking me on a full blown nostalgia trip

 

[liq001]

now the price is ridiculous. 87 is all most 5 dollar per gallon.

 

[Mountain Whiskey]

Yea, but reading from the first posts still has me chuckling. Putting different octane gas in the tank makes the transmission shift better in all my vehicles. Whew! Yep because that runs the transmission. Yea buddy. Much better. I'm putting race fuel directly in my transmission next, that'll really make her go!

 

[JoeCo]

Yea, but reading from the first posts still has me chuckling. Putting different octane gas in the tank makes the transmission shift better in all my vehicles. Whew! Yep because that runs the transmission. Yea buddy. Much better. I'm putting race fuel directly in my transmission next, that'll really make her go!

Too bad this mobil gas isn't still around, we could at least be getting a serious HP boost.

 

[ferraiolo1]

Yea, but reading from the first posts still has me chuckling. Putting different octane gas in the tank makes the transmission shift better in all my vehicles. Whew! Yep because that runs the transmission. Yea buddy. Much better. I'm putting race fuel directly in my transmission next, that'll really make her go!

Kinda how people think adding a cai changes shift patterns too! Lol

Here in Glorious pa. 93 was always around $0.50 more a gallon than 87. Nothing new now


Sent from my iPhone using Tapatalk

 

[FJB!!19limited]

Cheap gas was nice.....

 

[Fatherof3]

I've had my Rebel for a couple years now and I've tested the MPG on 87 , 89 & 93 . I ran 5 tanks of each but didn't include the first tank so the average is 4 tanks each .
87 = 22 MPG
89 = 24 MPG
93 = 26 MPG
All on the highway ( 100 KPH which is = to 62 MPH ) that's the speed limit up here and I'm too old to keep a look out for speed traps .
So if you can keep your speed around 60 MPH you can figure out how much extra $ you'll spend per tank and if it's even worth it .

 

[sep1006]

Been running 87 Octane in my 2021 Rebel ( 5.7 hemi ) since day 1 and it runs great. Always fill up at a Chevron or Texaco because of the Techron, no issues whatsoever!!!

 

[VegasRob55]

I have a 2020 RAM Laramie with the 5.7 Hemi with 10,000 mile on the odometer, I figured I’d start out with that line..

I normally run mid grade fuel (89 octane) but recently, my parents took a trip from East Tennessee, to south Louisiana, and back.. I told them that they can run regular 87 octane to make it cheap on them.. the truck did excellent all the way around! They traveled 1600 miles with the cruise set at 78 mph majority of the time, and got 21.8 mpg..

When I got my truck back, it wouldn’t get up and run like it normally did with mid grade fuel.. not only that, the transmission was shuttering, and shifting harder than normal.. Keep in mind, I drive my truck pretty hard.. I started to notice a sound coming from the engine.. the sound sounded like metal on metal pinging under moderate to heavy throttle..

It finally clicked in my head what was happening, it was spark knocking due to running 87 octane, and I still had just under a half tank left.. So I ended up going to the gas station, and fueling it up with 93 octane.. after 7 miles under moderate to heavy throttle, the spark knock went away, and the transmission wasn’t shifting as hard, and the shutter wasn’t ether..

So I had an idea, on the next fill up, i had my wife put premium fuel (93 octane) in it, and we’ll see what happens! I’m a otr truck driver, so my wife is the only person that drives it when I’m away.. so a week later, she fills it up full of 93 octane, (it was at 1/16 of a tank when she filled it up) and she burned a quarter tank before I came home..

Needless to say, I was surprised with the results! There was no shuttering, or hard shifting out of the transmission, it actually knows where to shift a gear when I gun it, and the response of the throttle was definitely noticeable! As far as fuel economy, most of the time, we would get 15mpg running around town, now we get 17mpg.. I don’t have hwy numbers yet.. but, I’m taking a vacation in 10 day going down to Florida..

When I drove it around town, a guy turned into a place, and I decided to floor it at 25mph on dry roads, and it spun the tires with traction control on!

This is the 5.7l I’ve been wanting since I’ve bought it! And all it took was putting premium fuel in it!

I only run premium in my 19' Laramie, with the 5.7. Have since the day I bought it. Costco's premium is cheaper than everyone else's regular, and it's my closest gas station to home, so what the hell.

 

[VegasRob55]

now the price is ridiculous. 87 is all most 5 dollar per gallon.

FJB

 

[Richard320]

now the price is ridiculous. 87 is all most 5 dollar per gallon.

You're about a buck behind California

 

[RRSBighorn]

I've use 87 octane for every day driving, and haven' noticed any pinging since I bought my Ram. But last August did a 3000 mile trip from Chicago area to Yellowstone with my ~6k lb trailer. I logged all my gas milage through the trip. Going there, I was using 87 to start, cruising usually 65-75mph, got as low as 7.7 mpg and as high as 9.7 mpg. At some point in S Dakota I started using mid grade and sometime high octane. Also used ethanol free when available. I noticed the mileage was going up. The average going there was ~8.5-9 mpg. Coming back 10 days later stayed with 90+ octane and ethanol free when possible. The lowest mileage I got was 9.6 mpg, and highest was11.4 mpg. Gas mileage seemed to average around 10.5-11mpg coming back. Obviously many variables can affect mpg, but I concluded that it was worth using higher octane and or ethanol free when towing my TT.
Back to everyday use, using 87 octane with ethanol. Doesn't seem to have as much power, but never notice pinging, gas mileage close to what sticker said, so staying with it. If I have heavy load or trailer, I will use higher octane fuels.

I worked my career in oil refining R&D for a major oil company. I always use top tier fuels, you get better additives package compared to 2nd tier fuels. The base fuels are basically the same, it's the additives that are blended in at the fuel terminals that make the difference. I am not brand loyal to the company I worked for 41+ years though.

 

[Mountain Whiskey]

I've use 87 octane for every day driving, and haven' noticed any pinging since I bought my Ram. But last August did a 3000 mile trip from Chicago area to Yellowstone with my ~6k lb trailer. I logged all my gas milage through the trip. Going there, I was using 87 to start, cruising usually 65-75mph, got as low as 7.7 mpg and as high as 9.7 mpg. At some point in S Dakota I started using mid grade and sometime high octane. Also used ethanol free when available. I noticed the mileage was going up. The average going there was ~8.5-9 mpg. Coming back 10 days later stayed with 90+ octane and ethanol free when possible. The lowest mileage I got was 9.6 mpg, and highest was11.4 mpg. Gas mileage seemed to average around 10.5-11mpg coming back. Obviously many variables can affect mpg, but I concluded that it was worth using higher octane and or ethanol free when towing my TT.
Back to everyday use, using 87 octane with ethanol. Doesn't seem to have as much power, but never notice pinging, gas mileage close to what sticker said, so staying with it. If I have heavy load or trailer, I will use higher octane fuels.

I worked my career in oil refining R&D for a major oil company. I always use top tier fuels, you get better additives package compared to 2nd tier fuels. The base fuels are basically the same, it's the additives that are blended in at the fuel terminals that make the difference. I am not brand loyal to the company I worked for 41+ years though.

Yep, every day driving there is no use burning cash.

Hey, did you stop and think that the reason you got improved milage on the way back wasn't the gasoline but the fact you drank all the beer and lightend the load?