Switching from 87 to 93 octane made a difference!

[kenthorkveen]

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!

 

[LimitedGRR]

It makes sense with better fuel to get better engine performance. Running 87 is nuts and asking for detonation problems even with computers making adjustments for cheap gas. The transmission was babied by your dad and it changed shift profiles, that’s why it was acting funny on you until it updated the shift profile again. The transmission uses software to learn the drivers habits. I think it has several profiles loaded into its system.


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[PhilBilly]

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!

Yes the higher octane makes a bug difference also if you can get it ethanol free (pure gasoline) it really makes a huge difference.

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[kenthorkveen]

Yes the higher octane makes a bug difference also if you can get it ethanol free (pure gasoline) it really makes a huge difference.

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I told the service manager at my local ram dealer, and he said the same thing.. (I was there getting an oil change)

 

[Trippi]

I normally run the 87 octane and the truck runs and shifts great. Tomorrow is gas day...I am going 93 this fill will be interested to see the driving and mpg results.

 

[kenthorkveen]

I normally run the 87 octane and the truck runs and shifts great. Tomorrow is gas day...I am going 93 this fill will be interested to see the driving and mpg results.

I think when my wife fueled up of of 1/16 of a tank, it was $54 at $2.40 a gallon.. we have a 26 gallon tank..

 

[PhilBilly]

There are not many stations that have ethanol free premium but it is worth the search.

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[UnloosedChewtoy]

87 ethanol-free octane would probably work just fine, but I bet they used 87 octane with 10% (or higher) ethanol at some point during that trip they took. Depending on what state you're in, they don't all require that it be labeled as containing ethanol either. Just a guess.

Definitely recommend ethanol free, 89+ octane, when you can for these Hemis, regardless of octane rating. That said, I'd definitely pick 87 octane ethanol free over 88/89 with 10%/15% ethanol. I've ran both, back to back, and she definitely liked the 87 ethanol-free better (that was in my 2014 Ram with the Hemi).

In my 2020, I run Costco's 91 octane (10% ethanol) because I get the points. If it weren't for the points, I'd be getting our gas at ethanol-free stations.

 

[kenthorkveen]

87 ethanol-free octane would probably work just fine, but I bet they used 87 octane with 10% (or higher) ethanol at some point during that trip they took. Depending on what state you're in, they don't all require that it be labeled as containing ethanol either. Just a guess.

Definitely recommend ethanol free, 89+ octane, when you can for these Hemis, regardless of octane rating. That said, I'd definitely pick 87 octane ethanol free over 88/89 with 10%/15% ethanol. I've ran both, back to back, and she definitely liked the 87 ethanol-free better (that was in my 2014 Ram with the Hemi).

In my 2020, I run Costco's 91 octane (10% ethanol) because I get the points. If it weren't for the points, I'd be getting our gas at ethanol-free stations.

89 ethanol free will be the next thing I try.. especially if it’s cheaper than running 93 all the time..

 

[LimitedGRR]

89 ethanol free will be the next thing I try.. especially if it’s cheaper than running 93 all the time..

Have 3 stations around me with ethanol free gas. Pricey though at 3.50 -3.80 a gallon. I don’t think ethanol free gas is cheaper anywhere vs the ethanol version. I run the ethanol free in my classic muscle cars and lawn equipment Makes a big difference!


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[kenthorkveen]

Have 3 stations around me with ethanol free gas. Pricey though at 3.50 -3.80 a gallon. I don’t think ethanol free gas is cheaper anywhere vs the ethanol version. I run the ethanol free in my classic muscle cars and lawn equipment Makes a big difference!


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It depends on what state you live in also.. regular 87 octane is $1.79 where I live at in Tennessee.. I think non ethanol will probably be the same price of premium, or lower which is $2.43 or lower.. we have a pretty large gas station chain that sells it all there pumps.. so non ethanol is plentiful here..

 

[gpbst3]

The computer must have updated for the difference in driving style.

I run 87 octane and have had a 21mph with a full cargo load on a 1200 mile trip.

93 octane is about .50 a gallon more. There is nothing it will do to justify the 20% price increase.

 

[Granite2WD]

The computer must have updated for the difference in driving style.

I run 87 octane and have had a 21mph with a full cargo load on a 1200 mile trip.

93 octane is about .50 a gallon more. There is nothing it will do to justify the 20% price increase.

It depends where you live, but in my area, 93 is at least 0.50 more per gallon. At the end of the day it's whatever makes you happy, but the owner's manual says 87 is fine and it works for most. I think anything above that is diminishing returns in real life, but maybe a strong placebo effect.

 

[SpeedyV]

It depends where you live, but in my area, 93 is at least 0.50 more per gallon. At the end of the day it's whatever makes you happy, but the owner's manual says 87 is fine and it works for most. I think anything above that is diminishing returns in real life, but maybe a strong placebo effect.

It says 89 is recommended "...for optimum performance and fuel economy." It also says that "While operating on gasoline with an octane number of 87, hearing a light knocking sound from the engine is not a cause for concern. However, if the engine is heard making a heavy knocking sound, see your dealer immediately. Use of gasoline with an octane number lower than 87 can cause engine failure and may void or not be covered by the New Vehicle Limited Warranty."

I wouldn't go so far as saying 87 is "fine". It is acceptable if you can't find or afford to run 89, but the engine is obviously tuned for 89.

Note: At least one member on here ran tests and found that the computer was still pulling a bit of timing even on premium (worse on 89, and much worse on 87). His results suggest that premium is beneficial, at least for his engine and testing conditions.

Personally, I've experienced mixed results when trying different fuel grades. I've achieved my best-ever fuel economy on 93, but I've averaged just as high on 89. I don't put a lot of miles on my truck, so I've generally been sticking with premium "TOP TIER" fuel from QuikTrip.

 

[mikeru82]

There are not many stations that have ethanol free premium but it is worth the search.

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It's just the opposite where I live. The only ethanol free gasoline in the area is 92 octane. And it costs 80 cents per gallon more than the 89 w/10% ethanol. I ran 87 in my truck for the first six months until I realized that 89 octane was recommended. I've noticed a fuel mileage increase of almost 2 mpg since switching to 89. I might try a tank or two of the 92 octane eth free to see if it makes a difference, but there's no way that any fuel mileage increase will overcome the $15+ per tank more I'll be paying each fill-up.

 

[Timeless]

Yes the higher octane makes a bug difference also if you can get it ethanol free (pure gasoline) it really makes a huge difference.

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Ethanol free would only make a difference in the MPG...as far as performance it would be the same.

 

[Buz]

I normally run the 87 octane and the truck runs and shifts great. Tomorrow is gas day...I am going 93 this fill will be interested to see the driving and mpg results.

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.

 

[Granite2WD]

It says 89 is recommended "...for optimum performance and fuel economy." It also says that "While operating on gasoline with an octane number of 87, hearing a light knocking sound from the engine is not a cause for concern. However, if the engine is heard making a heavy knocking sound, see your dealer immediately. Use of gasoline with an octane number lower than 87 can cause engine failure and may void or not be covered by the New Vehicle Limited Warranty."

I wouldn't go so far as saying 87 is "fine". It is acceptable if you can't find or afford to run 89, but the engine is obviously tuned for 89.

Note: At least one member on here ran tests and found that the computer was still pulling a bit of timing even on premium (worse on 89, and much worse on 87). His results suggest that premium is beneficial, at least for his engine and testing conditions.

Personally, I've experienced mixed results when trying different fuel grades. I've achieved my best-ever fuel economy on 93, but I've averaged just as high on 89. I don't put a lot of miles on my truck, so I've generally been sticking with premium "TOP TIER" fuel from QuikTrip.

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.

 

[SpeedyV]

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.

Good research, there.

 

[kenthorkveen]

It says 89 is recommended "...for optimum performance and fuel economy." It also says that "While operating on gasoline with an octane number of 87, hearing a light knocking sound from the engine is not a cause for concern. However, if the engine is heard making a heavy knocking sound, see your dealer immediately. Use of gasoline with an octane number lower than 87 can cause engine failure and may void or not be covered by the New Vehicle Limited Warranty."

I wouldn't go so far as saying 87 is "fine". It is acceptable if you can't find or afford to run 89, but the engine is obviously tuned for 89.

Note: At least one member on here ran tests and found that the computer was still pulling a bit of timing even on premium (worse on 89, and much worse on 87). His results suggest that premium is beneficial, at least for his engine and testing conditions.

Personally, I've experienced mixed results when trying different fuel grades. I've achieved my best-ever fuel economy on 93, but I've averaged just as high on 89. I don't put a lot of miles on my truck, so I've generally been sticking with premium "TOP TIER" fuel from QuikTrip.

Now that’s the response I wanted! I remember seeing something in the manual about all of this, but I slept since then.. and I definitely seen the post about that one guy saying that the computer was pulling a bunch of timing on 87..