[Diesel_Dave]

I can't help but be proud of myself for this last tank (filled up this morning). This is better than I would have ever thought possible. Here is the details:

Distance: 1,435.0 miles
Fuel Usage: 35.000 gallons
Key-On Time: 49 hrs, 42 min
Avg. temperature: 67 deg F
Dates: May 7 to June 15
Avg. in-cab mileage display: 43.92 mpg
Actual mileage: 41.0 mpg

The majority of these miles were back and forth to work: a total of 50 commutes. I filled up at the same station, same pump and both times the fuel level was visible in the filler neck (I have a 34 gal tank). The reason the fuel quantity is exactly 35 gallons is because I get a discount at that station for up to 35 gallons in one fillup (it will cut me off at 35 gal). If I run almost all the way to empty and then top off it works out perfect every time.

I've also verified my odometer with Google Maps.

This is in comparison to by previous best tank (my last one) of 34.14 mpg. Here are the things that helped me go from 34 to 41 mpg:

1) Better weather. This tank was, on average, 9 deg F warmer than the last as summer is approaching. In addition, it's been really dry here so there wasn't much rain.
2) Right near the end of last tank I switched my oil from 15W-40 conventional to 5W-30 synthetic.
3) Focusing like crazy on my driving style. I really started using more EOC, and trying to really focus on every trip (leaving the radio off, etc.) Over the winter my mileage had gone down a little because of the temperature so I think I'd started to get a little lazy.

I estimate the effect of each of the individual effects above had about an equal weight (~2-3 mpg each).

I'm pretty sure this hasn't been done before. I believe the 1,435 miles on one tank is an Ecomodder record--the previous best I could find was groar's 1,268.9 miles. While there's no way to tell for certain, I think it may also be a distance record for any pickup truck as well (with a stock tank). I suspect that 41.0 mpg may be a record for real-world mileage in a full-size pickup as well.

This also puts my 90-day/3-tank average at 36.3 miles per gallon, which is 6.48 L/100 km. To the best of my knowledge this is the first demonstration of L/100 km fuel economy that is lower than engine displacement (my engine is 6.7L).

Thanks to all the Ecomodder folks that have given me ideas, tips, & motivation!