In the past Americans and Europeans have been worlds apart when it comes to diesel vehicles.  Diesel passenger vehicles have been popular in Europe for years and continue to grow in popularity.  In fact, according to a survey performed by Eurocarprice.com and Pricewaterhouse Coopers, diesel car sales in Europe were on pace to exceed gasoline car sales in 2006.  Even in the United Kingdom, which has the highest diesel fuel prices in Europe, gasoline-fueled car sales dropped 11 percent last year while diesel-fueled car sales increased by more than 7 percent.

In America, diesel passenger vehicles have traditionally been a tough sell, with many Americans harboring negative impressions of diesel vehicles as being noisy, polluting and foul-smelling.  However, industry experts predict a dramatic comeback for diesel passenger vehicles in America.  According to TechnoMetrica, diesel vehicles may eventually become as common in the United States as they are in Europe, and J.D. Power and Associates projects diesel sales to nearly triple in the United States over the next decade, accounting for more than 10 percent of U.S. vehicle sales by 2015.

Diesel technology has come a long way since the 1970s, and stringent new federal diesel emissions requirements are now in effect for 2007.  Today’s new generation of diesel engines is designed to not only meet stringent federal clean air requirements but also to be as quiet and odor-free as gasoline engines, increase fuel economy by 25 to 40 percent and provide enough torque to satisfy American drivers.

A significant breakthrough in this new era of clean diesel technology was the recent introduction of ultra low sulfur diesel (ULSD) fuel.  Sulfur is a key element to particulate formation, and ULSD eliminates 97 percent of pollution-causing sulfur.  While present diesel passenger vehicles can be sold in all states except California, New York, Vermont, Massachusetts and New Jersey, automakers plan to take advantage of new ultra low sulfur Diesel fuel and advances in diesel technology to create diesel engines that meet the pollution requirements in all 50 states.

Automakers are developing different pollution-reducing technologies for future diesel passenger vehicle models.  For example, DaimlerChrysler and General Motors plan to introduce engines that inject urea into the cylinders during combustion.  Honda, on the other hand, recently announced the development of a new catalytic converter that significantly reduces nitrogen oxide (NOx).

The benefits of diesel engines have made them the most common "workhorse" in trucking, shipping, construction, farming and industry. Their adaptability to automobiles and small trucks has proven to be successful, and today more and more light-duty vehicles are being equipped with diesel engines.

But with soaring fuel prices in 2005-06, diesels have also become attractive because of their fuel economy, even though lately diesel fuel has been higher priced than gasoline. Diesel-powered vehicles typically get 30 percent better mileage than gasoline-powered vehicles. This is due to the difference in the way gasoline powered engines and diesels form energy. 

Gasoline engines compress a mixture of gasoline and air, which is ignited with a spark from a spark plug, while a diesel engine creates heat by compressing air only.  The fuel is injected into the compressed air, where the heat ignites it.

Diesel engines create power more efficiently than gasoline engines because their compression ratios are higher.  Diesel engines compress at ratios between 14:1 and 25:1 while gasoline engines compress at ratios between 8:1 and 12:1.

In addition, diesel fuel creates energy more efficiently than gasoline due to its higher energy density.  One gallon of diesel fuel contains approximately 147,000 BTU, while one gallon of gasoline contains about 125,000 BTU.  (BTU = British Thermal Unit, a standard unit of energy, equivalent to 1055 Joules.)

Because of contemporary concerns about the supply of energy, diesel technology has been gaining ground as numerous auto manufacturers pursue diesel passenger car projects.  In fact, last year Audi won the 24 Hours of Le Mans with two diesel cars and opened a lot of peoples’ eyes to their blend of fuel economy and power. And they did it in style.
 

Although diesels are built sturdier, when they do require maintenance they cost more to repair. Replacement parts are more expensive, maintenance costs higher, and qualified mechanics often hard to find.   

Diesel cars and trucks often require fuel additives for improving operation. Become familiar with the various products that clean the fuel system, improve combustion, reduce emissions and black smoke, reduce gelling and help keep fuel stable in storage. To help raise the cetane numbers in diesel fuel several companies sell a cetane booster fuel additive.  There are products on the market that address the problems inherent in diesels.  

Synthetic oils are another way to improve diesel performance. As noted, diesels can be dirtier. Synthetic diesel oils tend to be formulated with a stronger detergent dispersant additive package to help address the extra soot and by-products of combustion.  Premium synthetic oils keep engines cleaner.  Also, because of their higher film strength synthetic lubes are better at handling higher temperatures and loads.

For cold climate diesel owners synthetic oils are almost a must.  We mentioned earlier the importance of starting speed.  In frigid northern tier states conventional lubes cause engine drag that almost cripples the starting capabilities of a diesel. No one appreciates the lower pour points of a synthetic oil more than diesel owners.

Diesel pickup owners tend to be performance minded.  Carrying added products such as cetane boosters, and premium synthetics will appeal to this consumer.  These are the “muscle cars” of the new millennium.