If you are in the market for a new pickup, you may be wondering which type to choose. Do you go for a gasoline or diesel fuel powered engine? So what is the difference between diesel and gas engines? Here we will break down the differences and similarities between the two so that you can make an informed decision.


There are significant chemical differences between the two fuels, however, how the engines consume them is very similar. Here is a list of some of the ways they are similar:

  • Both are internal combustion engines which use controlled combustion to convert fuel into energy
  • They both compress an air/fuel mixture in the engine
  • To obtain the power needed to operate, the fuel needs to ignite in both types of engines
  • Both use emission control systems, such as an EGR regulation system, to re-burn particulate matter in the combustion chamber
  • Fuel injection is the main source of induction for both engines


While there are many similarities between diesel and gasoline engines, there are also a few distinct differences.

Horsepower and Torque

This difference in engines may be the most persuasive for you in determining if a diesel engine or gas-powered engine is the better choice for you. A diesel vehicle will produce more torque (the force that gets the vehicle rolling). A gas-powered vehicle creates more horsepower, so, the engine spins more quickly allowing faster acceleration and driving speeds.

Hauling Capabilities

A diesel engine gives vehicles the power needed to pull heavy loads, such as utility trailers, RV’s, etc. Diesel engines are better suited for “trailering” up steep grades because of their torque advantage. The high compression ratio needed to ignite diesel fuel helps diesel engines to create power and torque at a much lower RPM than gas engines.

Compression vs Spark Plugs

While diesel and gas-powered engines consume fuel in a similar way, the way they ignite the fuel is different. To ignite, diesel engines rely on compression whereas gas-powered engines use spark plugs.

In a gas-powered vehicle, the fuel and air are mixed together at a certain point just before the piston thrusts up to meet the spark plug. The spark plug will then ignite the air/fuel mixture forcing the piston back down delivering power from the drivetrain to the wheels.

When you have a diesel engine, the air/fuel mixture compresses early during the combustion process producing enough heat to ignite the fuel. The term that is used for this sort of startup is compression ignition. No spark plugs are needed in this process. If this effect should happen with a gas-powered engine you will hear a noticeable knocking, indicating possible engine damage. A diesel, however, is designed to operate this way.

Many manufacturers offer the same vehicle with a diesel and a gas-powered model. Before purchasing, you should consider what the vehicles main purpose will serve as well as take it for a test drive to determine which makes you more comfortable.

If you purchase a diesel pickup you will want to hire quality, expert diesel mechanics to keep it running in optimal condition. That’s where we come in! The Gem State Diesel team consists of ASE Master Certified diesel mechanics with extensive experience in diesel pickup engine maintenance and repair. Call 208.957.6106 or schedule an appointment online.