It is not uncommon to open the hood of a new diesel pickup and see a slew of wires and hoses and underneath it all something which resembles an engine. What happened to the good old days when we used to actually be able to see the engine and be able to work on it when we popped the hood? How did we get to this point with the light-duty diesel industry? Let’s take a step back in time when Ford and GM and Chrysler introduced their light-duty diesel engines. The year was 1983 and the engine was the 6.2-liter diesel.
This engine was a joint venture between Detroit Diesel engine company and General Motors, and came as an option in the 1/2, ¾, and one-ton pickups.
In the same year Ford introduced its diesel engine, the 6.9-liter International diesel. Both of these engines were indirect injected and naturally aspirated. It was not until 1989 that Chrysler appeared on the light-duty diesel scene with the direct-injected, turbo-charged, 5.9-liter Cummins engine.
All of these engines in the light-duty diesel industry had one thing in common: Simplicity! These engines were notable for their great fuel economy, lack of emissions equipment, easy-to-work-on status and reliability.
They all averaged 160 to 170 horsepower and made around 400 ft. lbs. of torque or less. Let’s jump forward 15-plus years to today and talk about the modern diesel engines in light-duty trucks.
Ford released its long-awaited Scorpion engine, which is built by Ford exclusively and features 400 horsepower and 800 ft. lbs. of torque. Comparably, GM has its LML Duramax engine, which produces 397 horsepower and 765 ft. lbs. of torque.
Chrysler still continues to run with the proven Cummins engine powerplant, now displacing 6.7 liters and producing 350 horsepower and 650 ft. lbs.
What do these engines all have in common? Complexity! Each one of these new engines benefits, and suffers, from emission-driven devices.
These devices include exhaust gas recirculation (commonly known as EGR), particulate filters and catalytic converters in the exhaust, to name a few, as well as urea (ammonia) injection. These are the devices which clutter up the engine bay, hinder fuel mileage and create reliability issues.
Why do we have all these emissions? Environmental Protection Agency (EPA) standards. Does it make vehicles more expensive? Yes. Does it cause vehicles to use more fuel? Yes. Is it harder on the engine? Yes.
So you might ask: What are the benefits to having a vehicle with the new emissions equipment on it? Well, the air exiting the exhaust can actually be cleaner than the air being inhaled in the intake.
This means that as you drive around, these engines are not only not contributing to the pollution problem, but actually cleaning the air, in essence.
In order for the current diesel engines to achieve such clean results, they have to benefit from the most current engine and fuel injection technology.
Each of the big three’s diesel engines benefit from features such as common rail injection, variable geometry turbos, extremely fast engine processing modules and many other technologically advanced pieces of equipment.
Each one of these advances now made available in recent years contribute to a cleaner-burning engine with fewer emissions.
In case you didn’t notice, these new engines also have about twice the power of their predecessors, due in large part to the advances in basic equipment driven by emissions-related regulations. So maybe the EPA and emissions-related regulations are not that bad after all.
When asked whether the EPA been the catalyst for engine advancements, we could probably answer “yes”, and they will most likely continue to be the catalyst for engine advancements.
So next time you pop the hood of a new diesel pickup and are disgusted by all the emissions equipment and other components stuffed into the engine bay, remember that if it wasn’t for emission standards, we would not have the technological advances in diesel engines that we do today. PD
Levi Perkins
Instructor, Diesel Program
College of Southern Idaho
lperkins@csi.net
