Abysmal fuel economy

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RoadRamblerNJ

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Yeah Im going back to 89 with my next tank. I know the switch over to winter gas has happened here too, and that tanks mpg all by itself. Hopefully 89 octane will bring some of it back. Ill also track the mpg difference to see if its really worth the extra cost since the price diff between 87 and 89 here is 20 cents or so per gallon.
Not worth it at those prices.
 

RoadRamblerNJ

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Federal law states Every car sold in the USA MUST be able to run normally on 87 octane gas.
Tires make a big difference in fuel economy as well. I would assume the window sticker fuel economy numbers are based on lower rolling resistance street tires, but I'm not sure on that. Put a wider, knobby tire on and rolling resistance goes WAY up.


I guess I don't get the 89 octane thing.. For you guys that run it, are you getting engine pinging that is prompting you to use 89? I know where I'm from, 89 octane is like $0.20/gal more per gallon than 87. The way I'm thinking it, even if you got 1mpg better with it, you're fuel cost is still higher than getting 1mpg less with 87.
 

PoMansRam

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Federal law states Every car sold in the USA MUST be able to run normally on 87 octane gas.

Yep I get that and I understand some high performance, higher compression ratio, etc, engines can 'de-tune' themselves to run on 87oct, but will perform better (as designed) on 89+. I do not think Ram hemi engines are designed as such.

In my area, some of my local gas stations sell 89oct "recreational fuel" for boats, ATVs, etc. I supposedly has 0% ethanol in it. I can definitely see where your fuel economy will increase with this particular fuel, but the increased cost for this gas will make it wash or worse. I love the stuff for my outdoor power equipment because of the lack of ethanol.
 

John813

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Yep I get that and I understand some high performance, higher compression ratio, etc, engines can 'de-tune' themselves to run on 87oct, but will perform better (as designed) on 89+. I do not think Ram hemi engines are designed as such.

In my area, some of my local gas stations sell 89oct "recreational fuel" for boats, ATVs, etc. I supposedly has 0% ethanol in it. I can definitely see where your fuel economy will increase with this particular fuel, but the increased cost for this gas will make it wash or worse. I love the stuff for my outdoor power equipment because of the lack of ethanol.

Down here in S FL a year or so ago the prices for 89 non ethanol were "reasonable"/no more than 93 octane. Now, it's 20-30 cents more than 93 in my area.
Used to run it every once in a while but I don't see the point if 93 is way cheaper.
 

JoeCo

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Down here in S FL a year or so ago the prices for 89 non ethanol were "reasonable"/no more than 93 octane. Now, it's 20-30 cents more than 93 in my area.
Used to run it every once in a while but I don't see the point if 93 is way cheaper.

Up in NY the ethanol free is 90 octane and is about 40-50 cents higher per gallon than 93 octane. I only know this because my 66 Buick loves the ethanol free so that's what I put in, I just wish the price was closer to 93 at least.
 

RoadRamblerNJ

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Your '66 Buick was also designed around leaded fuel, which lubricated the exhaust valves. Running a lead additive will enhance the longevity of your motors heads. And it lets you have cool conversations with folks that never knew there was lead in gasoline. :)
Up in NY the ethanol free is 90 octane and is about 40-50 cents higher per gallon than 93 octane. I only know this because my 66 Buick loves the ethanol free so that's what I put in, I just wish the price was closer to 93 at least.
 

JoeCo

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Your '66 Buick was also designed around leaded fuel, which lubricated the exhaust valves. Running a lead additive will enhance the longevity of your motors heads. And it lets you have cool conversations with folks that never knew there was lead in gasoline. :)

That's very true, I would have a hard time calculating how many cases of lead additive I've bought in the last 15 years. Regardless of the added cost of that and the ethanol free, I still drive it often and as "spirited" as I want. Sometimes you just have to enjoy things in life, even if it costs a little more.
 

RoadRamblerNJ

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Thank God, I'm not alone. Will you please talk to my wife.
That's very true, I would have a hard time calculating how many cases of lead additive I've bought in the last 15 years. Regardless of the added cost of that and the ethanol free, I still drive it often and as "spirited" as I want. Sometimes you just have to enjoy things in life, even if it costs a little more.
 

RoadRamblerNJ

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PS: I had a '66 Poncho Catalina 2 Dr. with the 400 cu in motor. It was my Grandma's car. They had no idea it went above 3000 RPM's.
 

JoeCo

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Thank God, I'm not alone. Will you please talk to my wife.

Haha I take it she does not think the same way? I got lucky with my gf, she thinks our way, spend away.

That's cool about the Catalina, I've always loved the look of the stacked headlights those had. I got my Buick when I was 17, my father didn't much like how I drove it through my teens and twenties. However, it still has the original drive train in it and its never given me much trouble at all so it clearly held up to the abuse.
 

RoadRamblerNJ

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Haha I take it she does not think the same way? I got lucky with my gf, she thinks our way, spend away.

That's cool about the Catalina, I've always loved the look of the stacked headlights those had. I got my Buick when I was 17, my father didn't much like how I drove it through my teens and twenties. However, it still has the original drive train in it and its never given me much trouble at all so it clearly held up to the abuse.
OK, typo...it was a '68. No stacked headlights.
And that "spendy-spendy=fun girlfriend". Yeah, right now you're spending "your" money. Go ahead, marry her. Becomes "our" money = "her yet unborn sons/daughters college money" ha! Try spending that on a new exhaust system.

OP, sorry for hijacking your gas mileage thread.
 

JoeCo

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OK, typo...it was a '68. No stacked headlights.
And that "spendy-spendy=fun girlfriend". Yeah, right now you're spending "your" money. Go ahead, marry her. Becomes "our" money = "her yet unborn sons/daughters college money" ha! Try spending that on a new exhaust system.

OP, sorry for hijacking your gas mileage thread.

Oh don't worry about that, I'm not getting married, ever. She's been married once and doesn't want to ever again, also her mother has been with her bf for 25+ years without marriage, so we figure that's what we are going for. My parents have been married for 40 years so I know it can go either way, but I've got too much I care about to risk losing any of it should **** hit the fan. Also I do love spending my money on stuff I want, that is also something I wouldn't be willing to give up.
 

QuasarZ

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Rebel with 450 miles averaging 15.6 combined.
 

Trent Layman

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I have a 2019 Ram 1500 Hemi E-torque and right out of the bag most of my driving was local and not much greater than 30-40 mph, and average went below 10mpg!! The throttle body had to be replaced and was hoping that would fix it.. didn't.. took back 2nd time and they ran all checks and was told to run a tank thru and figure mpg the ole fashion way by calculator.. did that and was right.. mostly local driving and about 100 miles on DFW highway.. average.. 12.9mpg! Took back third time and being told that this truck had alot of idling on it and that could be contributing.. they ran test again and found nothing. Manager drove it home and back and saw 16ish for mpg.. if that is true.. I'm good with that in town.. Anyone else hear about idling (I use auto start alot) contributing to mpg? That could be, but wouldn't it reset every time you zeor'ize mileage and mpg after you fill up? I'm in talks with Ram about lemon law.. Oh.. my truck has 3.21 gears..
 

Elkman

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If an engine is engineered for 87 octane gasoline then there is no benefit from buying a higher octane fuel. Octane is a measure of knock resistance from pre-ignition of the fuel as it enters the cylinders. The higher the compression ratio of a gas engine the more it is prone to pre-ignition and so more resistant fuel (higher octane number) is needed or the engine's computer will retard the spark to protect the engine. Using 87 octane gas in a high compression engine that is supposed to take 89 octane fuel will result in spark retardation and lower fuel economy and no real savings with the cheaper fuel.

My old 1998 Chevy Tahoe SUV used 87 octane fuel and averaged 16 mpg over 160,000 miles of driving. The 2018 4WD Chevy Tahoe is EPA rated at a combined fuel economy of 13 MPG and is more likely to be at around 11-12 mpg in real use. My 2018 Chevy Traverse is the same size as the Tahoe though with a great deal more cargo space, and it has averaged 22 mpg over the past 5,000 miles. The Tahoe's after 1998 provided more interior gadgets and better 0-60 performance but gas mileage got worse over the past 20 years. Much the same with pickup trucks where the horsepower keeps increasing along with the towing capacity but not the fuel economy - no surprise!

Ethanol provides 25% less btu's than gasoline and unless it is selling for under $2 a gallon it is a terrible fuel to burn. It is however, highly profitable for Archer Daniels Midland with the billions of taxpayer dollars spent on subsidies for corn.

With a new vehicle I like to establish a baseline for fuel economy. I will fill up the tank and then drive 50-60 miles at 55 MPH and then fill up the tank again and calculate the MPG achieved. I know that this is going to be the best that I can expect and my average MPG is going to be much less. With my 2018 Traverse I get 30 mpg (averages 22 mpg) with this test and with my 2011 diesel 2500HD I get 20.5 mpg (averages 16 mpg). Then it becomes a trade-off as I can save a few minutes driving at higher speeds and expect to pay more in fuel costs. No free lunch as they say.

It is hard to overstate how much of an impact driving behavior has on fuel economy. With the Prius cars the EPA figures are 45-50 mpg depending upon the model year but competitive owners regularly get over 60 mpg. Truckers pulling 50,000 lb loads across the USA will get 6 mpg but there are drivers who routinely get 8-9 mpg with the same trucks in the same conditions. Fleet operators talk about needing more 8 mpg drivers as they save the companies a great deal of money that goes straight to the bottom line.
 

Johnsram

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Ethanol provides 25% less btu's than gasoline and unless it is selling for under $2 a gallon it is a terrible fuel to burn. It is however, highly profitable for Archer Daniels Midland with the billions of taxpayer dollars spent on subsidies for corn.

Why are we introducing btu's in an auto forum? This is not an hvac forum.

Corn easily adds 70-80 hp on my ZL1, with the added benefit of additional cooling. Corn is usually 20-25% less than gas, but you burn more so it's a wash. It's one of the best things for a supercharged engine, other than ice or ****. Plus, it smells great!
 

HammerHead

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I got 16 on my first tank. City/highway combined, on 87 octane .
Have gotten 18 to 18.4 on the next two tanks with 89 octane, same mix of driving.
This has been trying to keep my lead foot off the throttle.
I have about 1100 miles so far.
The octane rating does make a difference with both my trucks.
Give it some time. Should improve .
George
^^^^this^^^^

Higher octane will give you better gas mileage as stated above. I'm running ethanol free 87 and getting very good gas mileage for the 6.4.
Try a few tanks of premium or ethanol free gas, should be better.
 

RoadRamblerNJ

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Lots of variables here to consider. I noticed OP didn't list all specs on his truck. (Sorry if it came later & I missed it but it's 4:05 am LOL). Things to consider OP...
1. Miles on truck matter. It's not fully broken in until you reach about 15k.
2. Rear gear ratios, tire selection, tire pressure, trans, driving habits, altitude, fuel mixture (NOT to be confused with octane rating), wind speed/direction, vehicle weight, radio station selection, political affiliation and the gravitational pull of the moon all matter. Some more than others.
3. Hand calculation at fill-ups vs the Lie-O-Meter in the dashboard (it is always optimmstic).

If you were really optimistic about mileage, you wouldn't have bought a brick. LOL (I Hope).
 

Geoman15

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Also, if you’re looking for gas mileage, don’t get a Pedal Commander.
I’ve lost 2 mpg after installing mine. :cool:
Just feels too good to have that pedal response and engine sound.
I’m at 16-17 now, but am ok with that.
If I was worried about mileage, I wouldn’t have traded in my Accord at 29 mpg for the so called brick:p
George
 
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