I don't doubt you since it's spring time, temperatures are increasing. Considering that mpgs increase an average 3-6% with every 10° rise in outside temperatures your numbers are right in line. Weather plays a much bigger role in mpgs than people give it credit for.
That's why when people here say they had such and such an increase in mpgs due to such and such a modification that I give it zero credence.

Also take notice that I previously said we only found drops in mpgs and power with mixes higher than B20.

 

Could this additive be classified as "free energy"?

 

Considering that mpgs increase an average 3-6% with every 10° rise in outside temperatures your numbers are right in line.

There ya go....I didn't know that. I would've thought that cold(er) air would have been more condusive to better power and mpg. I guess you DO learn something new everyday!! Gas engines seem to benefit from cool air and make more hp, I thought a diesel would've acted the same way. I wonder Bill at what point the outside temps hurt diesel performance & mpg?

 

Chux, the the effect of temperature on mpgs, believe it or not, is caused by increased aerodynamic drag at lower temps. Seems like there would be no upper end in this case. Temperature change also effects tire pressure which is a biggie on mileage.
Wet or dry pavement can make up to a 5% difference in mpgs also.
The temp of the oil in your differentials and tranny can make a 2% difference with high temps being better than cold.
For every 10 mph of headwind or crosswind, mpg is reduced by nearly 13%.

Here's one that really complicates figuring an mpg trend, most tires reach their minimum rolling resistance at 35-50k. Although it is a small percentage of the mpg equation it means you should continually be getting better mpgs as the tires wear if everything else stays equal (which is impossible).
The road surface can make up to a 30% difference with smooth concrete being the best and rough chip sealed asphalt the worse.
All these factors separately may only make slight differences in mpg but when you add them all together the total can be significant. This is why figuring mpgs on the road becomes very complicated and often unreliable. My feeling is it would take several years of onroad gallons divided by miles to establish a trend.

Rock-Solid Proven MPG Rules
1) Every 2% reduction in aerodynamic drag results in approximately 1% improvement
in fuel economy.
2) Above 55 mph, each 1 mph increase in vehicle speed decreases fuel economy by an average 0.1 mpg.
3) Worn tires provide better fuel economy than new tires, up to 7% better fuel economy.
4) Used lug drive tires can get up to 0.4 mpg better than new lug tires.
5) Ribbed tires on the drive axle provide 2–4% better fuel economy than lugged tires.
6) Every 10 psi that a tire is underinflated reduces fuel economy by 1%.
7) Tires make biggest difference in mpg below around 50 mph; aerodynamics is the
most important factor over around 50 mph.
8) The most efficient drivers get about 30% better fuel economy than the least efficient drivers driving the same vehicle.

 

Just for giggles, and on the subject of this thread......

Local price for B20 BioDiesel......$3.10
Diesel fuel 2 miles away............$3.03

And for comparason......
These two prices are at the same station.
Regular unleaded gasoline........$3.04
E85 Ethanol/Gasoline blend......$3.20

It ain't easy (or cheap) being "Green".

 

I thought all the 87 and 89 octane were at least 10% ethanol now?

 

Yeah, but by supporting renewable fuels you create more incentive to produce more which should bring the price down.

 

And that's why I pay more for the Bio.

As for the Ethanol/gasoline blend.....
Pump gas is supposed to be 10% ethanol, the E85 is 85% Ethanol, 15% gasoline.
(It could be 100% alcohol, but they add the gasoline to keep people from drinking it)

 

Bill,
I thought that I read somewhere that there are marked diffrneces in Cetane and fuel quality dependant up on the seed fuel for BD. Plese tell me more about your testing.

Thanks,
Bob

 

Bob, the feed stock makes a great deal of difference but as mentioned previously it's the meal left over from oil extraction that is the real money maker.
This is one reason soy based BD (cetane 49) is the most widely available and what we used for testing.
Soy's cetane value is about in the middle compared to feed stocks.
There are definitely better feed stocks to use for BD such as mustard, rapeseed and cottonseed but they don't have the feed value that soy has.
Soy is also a well established crop in the US, planting others is an experimental risk that many farmers don't want to take on.

Most of my research now is crop involved. Looking at oil crops that haven't been explored much and what inputs provide the highest oil yields.
Right now Camelina is looking very promising. Grows like a weed and can be interplanted with other crops without reducing the yield of the main crop.

 

Bill are you a farmer and do you brew up your own BD??

 

I was a full time farmer for 35 years, got tired of busting butt only to lose money, leased the farm out and got a job in Ag research. Still farm but don't need to worry about profits, my crop is data. In fact my leased out farm is over in your territory, Chelan County.

I've toyed with the idea of making my own BD, it's easy.
Time is my concern, I'd rather spend my free time fishing. If diesel hits $10/gallon I'll probably jump into it.

The time consuming part is rounding up/collecting free used fryer oil. If you have to buy virgin oil it just isn't worth it.