Back before I was into diesel pickups (I look back on my days of thinking my F150 was fast like I look back on my days of thinking Starship was an excellent band), I remember hearing all the diesel owners brag about how great the fuel economy of a diesel pickup was.
They were big, loud, messy and they stunk. But a first-gen Dodge Cummins would roll around at 20 miles per gallon, no matter what you did to it.
So why is it that 25 years later, the best we're getting is about 10 miles per gallon out of new diesel pickups?
The short answer is that diesels were big, loud, messy and they stunk. People who don't understand that trucks are big, loud, messy and stink because they do the work that makes the world go round used their political power to force the industry to clean things up to their standards.
Diesel engines are known for their torque. They make torque by nature of the combustion-ignition process. That process is dirty and loud by nature, and the crude fuel that diesels burn smells. So the ideal fix for the clean freaks would have been to eliminate diesels altogether. But the power to do that does not exist-yet. So regulations were imposed on manufacturers to clean up a dirty technology.
There is only so much that can be done to clean up the actual compression-ignition process. Everything else has to do with the intake and exhaust. That brought exhaust gas recirculation (or EGR) systems to the forefront. But that was overshadowed by the diesel particulate filter (DPF)-literally a trap for diesel exhaust soot that cleans itself out via regeneration until it craps out completely and leaves you stranded on the side of the road (raise your hand if we're talking about you). In essence, the engine is not really that clean; the exhaust is just filtering out the black smoke.
Now we get another cigarette-filter fix to the dirty technology-urea fluid. And on top of it all, the manufacturers are continually upping the horsepower and torque output (2011 engines are knocking on 400-horsepower stock). That's a good thing, but it does nothing for the dirty problem since fuel creates emissions and it takes fuel to make horsepower.
But what really caught my eye amid all the 2011 releases this year was the fuel economy improvements. Press releases are exclaiming phrases like "10 percent improvement in fuel economy!" Wow. I think I can do the math without a calculator this time. Ten percent of 10 is. one.
We're up to 11 miles per gallon. Problem solved.
No wonder late-90s Cummins pickups are worth so much.