Detailed statistical analysis of weather data from my daily log

[ConnClark]

Dave,


Not to be a kill joy but how does winter diesel figure into your equation?

[Diesel_Dave]

Originally Posted by ConnClark

Dave,


Not to be a kill joy but how does winter diesel figure into your equation?

I haven't accounted for it. For one thing I have no way of knowing what blend I get on any given fill.

Lots of people gripe about winter diesel killing their mileage. I'm of the opinion that winter itself makes much more of a difference than the winter diesel does. Summer diesel is pure #2 diesel. Winter diesel is often a blend of #1 & #2 diesel, with the blend depending on the time of year and the geographic location. #1 diesel does contain less energy per gallon than #2 does, however, if you look at the actual numbers, pure #1 diesel contains only about 4% less energy than pure #2 diesel. So if the blend were 50-50, that's only a 2% hit. So that's only going to make as much difference as a 4 deg F temperature change.

Also, I've read that additives are being used more and more to make winter diesel as opposed to blending with #1. I suspect this makes less difference int FE than blending.

I also keep a very detailed daily log. I've never been able to see any significant difference that's happened between tanks that might have been the result of fuel variation--so if there is a difference, I've never been able to see it.

[ConnClark]

diesel number 2 BTUs a gallon 133,000
winter blend diesel number 2 BTUs a gallon 129,000

about 3.1%

At 30mpg a 3.33% difference is 1 mpg

Also you may not see a sharp jump due to mixing of the two blends at the gas station and distribution holding tanks.