Why Diesel Vehicles are Superior 

To begin you need to understand the two main types of vehicle motors in use today.

Otto motors- Convert liquid energy, such as gasoline, with a source of heat from a spark (spark plugs) in the combustion cylinders into mechanical energy. Ingnition 

Diesel motors- Convert liquid energy, such as diesel fuel, with a source of heat from compression (no spark plugs) in the combustion cylinders into mechanical energy. Compression

Due to the difference in the approach to combustion the two style motors provide some valuable differences. To start with, you have the Otto cycle motors that require higher RPM's than the Diesel motors to achieve greater horse power. 

Horse power for Otto motors usually looks higher at first to the untraind eye due to different marketing campaings for vehicles in the past. With diesel vehicles it is not about your usual HP but more about Torque Horse Power. The true test of strength is measured with Torgue HP because stating HP (in general) is not always an acurate way to measure a vehicles power output. 

Diesel vehicles on average achieve much higher HP when measured by Torque. In addition to having higher torque they will achieve this with lower RPM's. This is due to the fact that diesel fuel by comparision to gasoline usually contains more energy by volume and the characteristics of compression over ignition.

With this being said, diesels will have fewer moving parts and the parts will not move as frequently. Having your parts move less provides fewer opportunities for failure and less wear and tear in addition bringing longevity to the motors. 

A few examples of long lasting diesel vehicles is the ubundance of high mileage semi trucks on the roads with over 300,000 miles and some exceeding 1,000,000 miles.

There was even a greek taxi cab driver who logged more than 4.6 million kilometers in his 1976 Mercedes Benz 240 D...WOW!!!

Diesels will also get higher fuel economy and are more effecient. The VW company even produced a prototype diesel that achieved over 200 miles per gallon. Some more realistic numbers are the Smart Car ForTwo CDi that can achieve over 70 MPG, VW TDi's, and Mercedes CDi's that can all achieve over 40 MPG and they don't look any different from the gas version. In addition, the U.S. trucks from GM, Ford, and Dodge have excellent diesels that have incrediable power and are fuel efficient compared to their gas versions with similar power.

Many people still think of diesels as smelly and loud, but this is far from the truth. Most diesels would not even be noticed anymore. Even if you were sitting on the hood you could almost forget they are running. Smelly and dirty diesels will soon not exisit due to some new cleaner technologies that are coming to market, not to mention biodiesel.

Primary benefits to Diesels are:

Last a long time (smaller carbon foot print than hybrid technology)

Fuel Effecient

Environmentally Friendly (especially when using biodiesel)

Higher Resale Values