Gasoline Grade Affect on Towing?

[OC455]

Made another trip out to Lake George this week for vacation with the family again. I topped off the tank with regular gas (87 octane) and drove out. Almost burned 3/4 of a tank going out there. It's mostly down hill traveling East on the 90.

Had to go back for a detail for work the next morning, topped off and round trip I burned a little more than a half of a tank of gas. Regular gas (87 octane)

Last night, before hooking up and leaving, the boss lady had $0.70 off a gallon of gasoline on her Advantage card. I went to the gas station and topped off. Inadvertently hit the Mid-grade button (89 octane). No biggie, still better than paying what it would be for full price regular gas.

On the way back, I did notice the Ram wasn't down shifting into the lower gears as much and was holding 65 MPH on the cruise control without much issue. The Ram was running great, the trans temps didn't get any higher than 199 degrees Fahrenheit on any of the long hills when it was pulling the TT. The Ram seemed to stay in the higher gears more and only downshifted on the long hill (6th gear only and no lower).

I used more than a half a tank of gas on the way back, but no where near as much the last return trip, or going out to Lake George, (Westbound on I90 and more uphill and a bit of head wind). Has anyone noticed their Ram running better while towing on the better grade fuels?

 

[Ramnewbie]

What engine do you have?

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[jerryt]

The owners manual for my 2004 1500 hemi recomends 89 octane mid grade.

 

[22hemi13]

I haven’t noticed a diff running 87 or 89. I have the 5.7 in my 2500. What I do notice is it runs better on chevron vs any other brand of gas.

 

[SyN]

When I had my 2014 Ram 5.7L I just ran 91oct when towing out of habit.
I did run 89oct every fillup though.

91 is the highest octane @ the pumps here.
They have 93-94 in the metro.

 

[xcaliber]

Do these hemi engines have knock sensors to utilize higher octane fuel?

My 04 WJ overland does.

 

[McBroom]

Made another trip out to Lake George this week for vacation with the family again. I topped off the tank with regular gas (87 octane) and drove out. Almost burned 3/4 of a tank going out there. It's mostly down hill traveling East on the 90.

Had to go back for a detail for work the next morning, topped off and round trip I burned a little more than a half of a tank of gas. Regular gas (87 octane)

Last night, before hooking up and leaving, the boss lady had $0.70 off a gallon of gasoline on her Advantage card. I went to the gas station and topped off. Inadvertently hit the Mid-grade button (89 octane). No biggie, still better than paying what it would be for full price regular gas.

On the way back, I did notice the Ram wasn't down shifting into the lower gears as much and was holding 65 MPH on the cruise control without much issue. The Ram was running great, the trans temps didn't get any higher than 199 degrees Fahrenheit on any of the long hills when it was pulling the TT. The Ram seemed to stay in the higher gears more and only downshifted on the long hill (6th gear only and no lower).

I used more than a half a tank of gas on the way back, but no where near as much the last return trip, or going out to Lake George, (Westbound on I90 and more uphill and a bit of head wind). Has anyone noticed their Ram running better while towing on the better grade fuels?

Yes it does make a big difference. I run 93 in my 2500 4x4 as often as my wallet allows. On the 93 w/o towing I get around 18 with a trailer I get about 14. I have the 6.4 and 3.73 gears.
On 87 I get about 14.7-16 depending on where I’m going. My numbers are combined city and highway


I Love my 18 Ram 2500HD 4x4 CC
Blue Streak Pearl off-road package

 

[Ramnewbie]

Do these hemi engines have knock sensors to utilize higher octane fuel?

My 04 WJ overland does.

The knock sensors are so you can run lower octane fuel. The knock sensors will retard timing if they sense preignition. The stock Hemi's are tuned for the recommended 89 octane but 87 is ok per owners manual. If it senses preignition on 87 octane, or any fuel actually, it will pull back timing to stop the preignition.

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[xcaliber]

The knock sensors are so you can run lower octane fuel. The knock sensors will retard timing if they sense preignition. The stock Hemi's are tuned for the recommended 89 octane but 87 is ok per owners manual. If it senses preignition on 87 octane, or any fuel actually, it will pull back timing to stop the preignition.

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What I meant was can I run higher octane fuel and see an hp gain from it. I tried reading my manual but I cant find anything in it.

 

[Ramnewbie]

What I meant was can I run higher octane fuel and see an hp gain from it. I tried reading my manual but I cant find anything in it.

That is subject to great debate. Higher octane is not going to hurt, and you could possibly see minimal gains however to get all you can get you need to get a tuner with a 93 octane tune and then run 93 octane.

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[OC455]

What engine do you have?

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5.7 Hemi....

I was wondering if anyone else has had similar results when towing with a higher grade gasoline. I figured when towing it really wouldn't make that much of a difference. I understand the higher grade gas for performance and such.

 

[WilliamS]

Higher octane could help only if the engine was tuned to advance timing based on the knock sensors. If the engine were tuned using the best possible fuel in the US which I believe is 93 unless you get one of those off stations that mixes at the store, which I will never use then yes there could be minimal gains. Knock sensors are to pull timing for poor fuel conditions, elevation difference and heat. Not usually for more power but to maintain current power levels.

The downside is once you run 93 for a long enough time and the engine starts to write into the long term fuel trims and you drop back to 87 you may notice knock or ping until the computer compensates.

Now if you were running a tuner or forced induction then yes Octane can make a huge difference.

 

[Ramnewbie]

Does the computer actually compensate for running 93 with a stock tune? I've had my Hemi for about 1 1/2 year and up until recently I had been running 93 in it all the time. Just recently I started running 89 and seems to be smoother, especially when engine hasn't fully warmed up yet. Seat of the pants can't tell any performance difference. Gas mileage. ????, Really could tell you for sure, it's right in line with where it was before.

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[GsRAM]

Does the computer actually compensate for running 93 with a stock tune? I've had my Hemi for about 1 1/2 year and up until recently I had been running 93 in it all the time. Just recently I started running 89 and seems to be smoother, especially when engine hasn't fully warmed up yet. Seat of the pants can't tell any performance difference. Gas mileage. ????, Really could tell you for sure, it's right in line with where it was before.

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Exactly correct. I've had my ram for 1.5 yrs now. When I first got it I ran nothing but 89 octane as the owners manual said it was recommended for my 6.4.

It runs good on the 89, but then fuel prices here in Taxalvania the welfare state went up big time and 89 was over $3/gallon. So I figured why not try 87? The manual does not say I can't run it.

I've been running 87 now for several months, probably 6 or so. At first I would not use it when towing my tt then I gave that a shot also.

The result? I've had no issues at all, no knock, nothing. Towing or not, I've noticed zero performance difference from the 89. Fuel mileage may possibly 1 mpg less, big whoop. In my area, 89 is 30-50 cents more per gallon and that adds up quick for no seat of the pants difference between the two.

Just my .02 but unless something changes, I'm running 87 going forward.

 

[xcaliber]

I have a flashpaq 3875 for my wj and it actually works fantastic it was worth every bit of the 450$ cad I spent on it

 

[silver surfer]

I have always run 89 octane when towing, no matter what truck I'm driving. Otherwise, I run 87 for the price difference.

 

[pacofortacos]

Also not all 87 octane fuels are the same and not all 89 fuels are the same.
I tend to run 89 for the most part when towing as the load on the engine is increased. Run 87 most all of the rest of the time.

Best fuel I have run so far was a tank of marine 90 octane no ethanol fuel - a +4 mpg increase while towing

The OP could have had a tank of 87 with 10 % or more ethanol and the 89 octane tank could have been less ethanol - it can make a difference.

 

[OC455]

Also not all 87 octane fuels are the same and not all 89 fuels are the same.
I tend to run 89 for the most part when towing as the load on the engine is increased. Run 87 most all of the rest of the time.

Best fuel I have run so far was a tank of marine 90 octane no ethanol fuel - a +4 mpg increase while towing

The OP could have had a tank of 87 with 10 % or more ethanol and the 89 octane tank could have been less ethanol - it can make a difference.

The non-ethanol gas around here the last I checked was $3.35 or more a gallon....a tad hard on the wallet.

 

[mtofell]

With my 6.4 Hemi I generally just run 87 when daily driving due to cost. When towing I'll try to plan ahead and get the 89. It's hard to say if I really notice any difference. There are just so many other factors like wind and terrain that it's hard to say. I was once in the backwoods and the only fuel available was 93 octane non-ethanol and I definitely noticed a difference in both power and MPGs. It's to be expected though since the non-ethanol just has more energy in a gallon than when ethanol is mixed in.

 

[billyw]

I started out always using 89 or better octane and eventually found myself just using 87 octane because it was cheaper. Somewhere along the way, I noticed the performance wasn't what it used to be. Did the usual things like change the air filter, etc. Finally got around to topping off the second half of the tank with 91 octane non-ethanol gas. The truck really woke up and was fun to drive again. Now I always try to run at least 89 octane, and tow with a mix of that 91 non-ethanol fuel in it. After that I did experiment a little too. Yes, it tows much better with 89 or better octane.