Gas or Diesel Pros and Cons in Class 3-4 Trucks

By November 15, 2011Fuel

Which works best for Class 3-4 truck engines – gasoline or diesel? It’s important to balance performance, fuel-efficiency and budget when making this decision for your truck fleet.

We’ll list 9 factors to assess when deciding between diesel or gasoline engines to help guide you in your decision.

  1. Fuel Efficiency – Advantage: Diesel – Since diesel fuel has a higher energy density than gasoline, it means less fuel is required to generate the same power as gas. This means a 30-35% fuel efficiency increase over gasoline (source: U.S. Department of Energy).
  2. Acquisition Cost – Advantage: Gasoline – In Class 3-4 trucks, the incremental cost is between $5-8,000 more than trucks with a gasoline engine. This price gap has nearly doubled over the last 7 years because of more stringent regulations.
  3. Fuel Cost Per Gallon – Advantage: Gasoline – Historically, diesel has been more expensive than gasoline, mainly because of higher taxes and environmental restrictions.
  4. Maintenance Cost – Advantage: Gasoline – Diesel engines have components on them that need servicing more often than gasoline engines. Filters need to be changed more frequently and the oil changes required are more expensive because oil reservoirs are larger than those found in gasoline engines.
  5. Engine Longevity – Advantage: Diesel – an example given is a comparison of the gasoline engine for Isuzu’s NPR cab-forward of 200,000 miles and the diesel engine is B-10 rated for 310,000 miles. The diesel engine is more efficient than the gasoline engine.
  6. Trailering – Advantage: Diesel – If your truck operation does a lot of towing, then the diesel engine would be a better fit for you. Extended towing using a truck with a gasoline engine would most likely result in a decreased engine life and increased fuel consumption.
  7. Specialty Body/Equipment Options -Advantage: Depends on upfit requirements
    Historically, PTO provisions were offered only on diesel engines, but more recently, depending on the manufacturer, PTO provisions are being offered on gasoline engines.
  8. Disposition/Resale – Advantage: Diesel
    This boils down to public perception. It’s perceived that a diesel engine with 150,000 miles on it will have more life in it than a gasoline engine with the same mileage.
  9. Environmental Impact – Advantage: Comparable
    This is considered comparable when weighing  the economy and mileage a diesel engine gets vs. the cost per gallon for the gasoline engine.

More on Evaluating Truck Engines

If you’re interested in an in-depth look at how gas vs. diesel factors in Class 3-4 trucks, click here to go to the Work Truck magazine.