Fuel Economy Series 60 Fuel Mileage battle.....

Mike

Well-Known Member
Staff member
The more power you are working with, the more important fuel quality is. At least, that is the way it was when messing with gas engines.

Back in high school, my Camaro ran like crap on pump gas. I bought most of it either at the track, or at a local airport.

Series 60 engines already weren’t designed for bioveggie liquid. Already a loss in efficiency there. Cetane, when you are commanding more power, becomes a bigger factor.
 
The more power you are working with, the more important fuel quality is. At least, that is the way it was when messing with gas engines.

Back in high school, my Camaro ran like crap on pump gas. I bought most of it either at the track, or at a local airport.

Series 60 engines already weren’t designed for bioveggie liquid. Already a loss in efficiency there. Cetane, when you are commanding more power, becomes a bigger factor.
Is cetane for diesel what octane is for gas?
 

ironpony

Professional Pot-Stirrer
Supporter
Mostly.

The true factor determining the quality of diesel is the BTU’s. Cetane factors into this.
Agreed.

Pulling 44,000 and setting 70 mph puts me in the lower 6's. At higher speeds I've heard, and this makes sense tome, that aerodynamic forces rise rapidly. So that's one factor against us. Still that doesn't explain the variability that mndriver mndriver is seeing.

My fuel economy jumps around too. I've always dealt with it by using longer term averages to filter out the noise. Running a couple of older trailers the last 45 days, gave me an average of 6.8, with the low in the period being 6.1 to a high of 8.1. The load that yielded the high was 2 pallets. That's significantly lower than with the mishmash of trailers I pulled at Prime, typically between 55 to 60 mph.
 

mndriver

curmudgeon extraordinare
Supporter
It's rare I show my tank to tank average.

Most of the time when I say I'm "5.8" or 6.3" mpg is a 3-day average.

The graph that I put up from time to time is just that. Y 30 day averages laid year over year for comparison.

ironpony ironpony hit the nail when he said my variability is so wide.


Cetane is just part of the package that makes up good fuel. Without the "package" you don't know what you've got. BTU content is a lot of it. Minnesota just announced that effective 4/1/18, they will mandate 20% biomass fuel at the pump. Double from last year.

I forget what the math works out to for it, but considering that biodiesel has 80% of the btu content over straight diesel, it's really becoming significant now.

Other than #1 diesel over the winter this year, I haven't bought diesel in Minnesota in some time. Sparta, Osseo, Ladysmith WI, clear lake IA, Steele ND, couple rural SD fuel stops, mainly coffee cups, are wear I'll get fuel.
 

ironpony

Professional Pot-Stirrer
Supporter
It's rare I show my tank to tank average.

Most of the time when I say I'm "5.8" or 6.3" mpg is a 3-day average.

The graph that I put up from time to time is just that. Y 30 day averages laid year over year for comparison.

ironpony ironpony hit the nail when he said my variability is so wide.


Cetane is just part of the package that makes up good fuel. Without the "package" you don't know what you've got. BTU content is a lot of it. Minnesota just announced that effective 4/1/18, they will mandate 20% biomass fuel at the pump. Double from last year.

I forget what the math works out to for it, but considering that biodiesel has 80% of the btu content over straight diesel, it's really becoming significant now.

Other than #1 diesel over the winter this year, I haven't bought diesel in Minnesota in some time. Sparta, Osseo, Ladysmith WI, clear lake IA, Steele ND, couple rural SD fuel stops, mainly coffee cups, are wear I'll get fuel.
The stickers on the pumps usually indicate 5% to 20% biomass. Maybe Keendriver Keendriver can shed some light on it, but I've been told by a couple of tanker yankers that the stuff is mixed at the feedracks when they load the stuff. It's kinda imprecise. For a given refinery, its probably going to be a relatively constant average - no matter which chain gets their juice there. Go down the road to a stop served by a different refinery, and and I'd bet that ratio is somewhat different. Cosequently the energy content will vary.
 

mndriver

curmudgeon extraordinare
Supporter
In 2013 when I was dealing with my fuel issues and working with several station managers and owners, it came clear how poorly it's mixed.

Even then they admitted that tank mixes were poor at best and their biodiesel could range from 5% to as much as 30% even in the winter.

So come winter, I try to just stick with #1 in the severely cold months as much as I can when I'm up North. I try to limit my total concentrate to 70% at most for the max.
 
In 2013 when I was dealing with my fuel issues and working with several station managers and owners, it came clear how poorly it's mixed.

Even then they admitted that tank mixes were poor at best and their biodiesel could range from 5% to as much as 30% even in the winter.

So come winter, I try to just stick with #1 in the severely cold months as much as I can when I'm up North. I try to limit my total concentrate to 70% at most for the max.
Why is that? The design of your motors fueling system?

I’ve driven 6-8 different trucks in winter and never worried about it as much as you do

Honest question. You had a lot more issues this past winter than I did
 

mndriver

curmudgeon extraordinare
Supporter
I'm not the only one having issues. There were a lot of trucks having problems this past winter. Mike Mike even started a thread on it this year.
What's up with the (lack of) winterized diesel fuel this winter season? (2017/2018)

Both of my trucks have performance tunes in them. The 12.7 is set to 565/1850 on a DDEC IV and my 14L DDEC V is set to 630/2350 for power.

Mike Mike and I were talking and it's like running a built up small block Chevy with high dome pistons and a cam, you can't run pump 87 octane fuel in it and 93 octane will likely be marginal at best.


Our tunes have likely made the trucks sensitive to fuel quality more than normal.

In the case of diesel, that means maintaining a cetane index of 48+ with premium fuel and not run #2 diesel which is 40-43 cetane.


JunkYardDog5958 JunkYardDog5958 just fueled up with Love's fuel. His mileage just tanked like mine did. Dropped over 0.7 mpg. We've also determined that him running Kelly KDA drives is destroying his fuel mileage as well. Before August, he'll likely be sporting, at the least, a set of aeolus hn308 tires like mine to replace them to get some of his fuel mileage back.

In the last 16 months, we've dropped $60,000 on both our trucks getting them both to this level of mechanical repair. In-frame included on both.
 
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mndriver

curmudgeon extraordinare
Supporter
According to the manager, this is what Sparta treats their fuel with.

IMG_20180608_145754882_HDR.jpg



According to my local distributor, this is what a lot of local farmers and the county use too.
 

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