Diesel fuel is very energy dense, up to 30% more chemical energy per gallon than gasoline. Modern Diesel engines combine direct injection with turbocharging to burn diesel in a way that gives good fuel economy to diesel vehicles, more than 40MPG in many cases at 70mph!
Diesel has a problem, as a dirty burning fuel, complex emission controls are needed to produce a clean burning Diesel engine system. Rudolf Diesel the inventor of the Diesel engine never imagined this to be possible, he design the original Diesel engine to run on Peanut Oil! With Petrochemical sulfur benzene PCAHC fuels, the Diesel engine produces a symphony of different toxic emissions, so many that to make a diesel vehicle cleaner, companies like Mercedes resorted to bubbling the exhaust of their diesel vehicles through synthetic urin, a urea solution that VW group calls Add Blue, these methods combined with EGR, lean burn modes, computer controlled ignigition & injection algorithms that optimize the emissions profile at different engines speeds and load settings.
Torque is king when towing or pulling off from a stop when you want to get moving. This makes electric vehicles awesome as electric motors produce peak torque almost instantly, but the batteries of today are not exactly able to power a long haul shipping container truck for interstate transporting routes, some day we will get their, first through hybridization.
The Diesel Hybrid is a partial solution to the externalities present in the diesel exhaust fumes. By hybridizing the duel engine with electric motors, emissions can be further slashed while fuel economy rises to statospheric levels. VW built the XL1 as a plug-in Hybrid Diesel platform that returns more than 200MPG, in a carbon fiber aluminum magnesium coupe similar in size to a Honda CR-Z or Mazda Miata... Think Compact Coupe!
Diesel engines are the default choice for backup generators in commercial and industrial applications. The diesel fuel with stabilizers can be stored for up to 15 years without spoiling, only propane is better able to be stored for longer periods! These slow spinning Diesel engine generators are the choice dejure at one of my favorite generator supply companies, Central Main Diesel!
I opted to get a gasoline hybrid manual tranny coupe rather than a VW TDI value edition Jetta in manual for two main reasons. Cleaner Air for Everyone, Cooler Technology. I believe in the ideas of hybridizing engines, and the IMA system that Honda used in the CRZ, was just cool enough to charm me over. The Lexus CT200H, the Toyota City Prius, the Honda CRZ man ex, and VW TDI Jetta Value Edition were at the top of my selection list for our next vehicle. Bored to tears with CVT PSD automatics after driving the Prius for 10 years, I had opt for either the TDI Jetta or CR-Z Hybrid. There is really nothing else like a Honda, so I went with the CR-Z!
Diesel Emissions have been raging in the news lately because of the Scandal at VW, where engineers and executives intentionally designed special cheating software into the diesel vehicles that VW builds so that those vehicles could cheat their way though emissions testing without getting caught. Some cleaver college students doing research on diesel fuel vehicles discovered the emissions problem, published their results, and that opened the box to the VW diesel scandal!
The Diesel Engines main problem is the Externalities of its Exhaust!
There is still a part of me that wants a turbo diesel motorcycle. The 2012 Toyota IQ JDM model with the D4S engines & manual transmission was something I kept thinking about for a long time. There is just something cool about diesel's retro technology. Diesel engines are known to last a long time because they have to be overbuilt to withstand constant compression ignigition and turbocharging. Long a maintain for ships and locomotives, Diesel engines not only make exception backup generators, the make torque low in the engine speed bands, making a manual diesel a pleasure to drive in and around cities with lots of stop and go, while also returning good fuel economy on highway trips.
At the end of the day gasoline is way too cheap in America to opt for diesel, especially with gasoline hybrids like the Toyota Prius family dominating the clean technology vehicle landscape of today!