Which Mack engine do you need? If that’s a hard question, don’t worry, we’ll explain the differences between each option and help you choose which is the right option for your truck. While the engines may all seem very similar, they do have some important differences that impact cost, performance and success.

Mack MP7 Engine

The first option is the Mack MP7 engine. Available with 325 to 425 horsepower, the MP7 provides power in a compact size. The MP7 is a great option when weight concerns overshadow power needs, coming in over 390 lbs lighter than the MP8. The newest model drops 51 lbs. and saves 2-5% in fuel consumption. The MP7 helps maximize payloads in weight-sensitive applications like bulk hauling and keeps route times down in refuse.

It also produces less soot due to reduced regens, meaning you’ll run cleaner. Mack’s wave piston design delivers 2% improvement in fuel economy and 90% reduction in soot. The waves in the piston bowl redirect flames in the combustion chamber to utilize all available oxygen for a cleaner and more complete burn than standard diesel pistons.

The latest MP7 engines are specially designed to meet the EPA 2017 standards. They reduce greenhouse gas emissions (CO2), helping to make your trucks some of the cleanest and most fuel-efficient on the road.

In terms of servicing, while all Mack engines are designed with serviceability in mind, the MP7 features a one-piece valve cover, making regular service easier than on engines with two-piece covers. And finally, the MP7 is the least expensive option.

Mack MP8 Engine

And when you need more power than the MP7 can provide, the MP8, the all-purpose Mack engine, is ready to tackle whatever work comes your way. Whether you’re hauling heavy loads like a Mack Granite dump truck or running at slower speeds with frequent stops like a Mack LR garbage truck, the MP8 delivers the muscle to shoulder heavy-duty vocational and highway workloads.

The MP8 now weighs 88 pounds less than the previous version, which means more payload per trip day in and day out—plus better operational efficiency and more revenue. While delivering consistent power and torque across a wide operating range, the MP8 can be tuned to your needs for the right mix of power and high fuel efficiency.

Mack MP8HE Engine

The MP8HE by comparison is the best option for fuel efficiency. Used with the right applications, the MP8HE is up to 6.5% more fuel efficient than the standard MP8. The best applications for the MP8HE are flat grades or rolling hills with light to moderate payloads at high road speeds. So, if most of your work is outside those applications, you won’t get the most efficiency out of the engine. Mack’s exhaust after treatment system is 17lbs lighter and takes up less space, which saves you fuel and money while improving flexibility.

Capturing heat that would otherwise be lost, the MP8HE’s Energy Recovery Technology feature converts exhaust emissions to mechanical energy and delivers it back to the crankshaft as torque. This process enables the engine to operate at 1,000-1,100 RPM, saving fuel without sacrificing performance. The MP8HE combines the proven performance of our MP8 engine with the high efficiency of ERT to capture lost energy, convert it to torque and reduce fuel consumption.

The MP8HE turbo also has the benefit of being more durable and generally less expensive to service. The fixed geometry of the HE’s turbo means fewer moving parts. Fewer moving parts gives you greater durability and requires less service. And when it does require service, that work is generally less expensive than on other models with variable geometry turbos. 

Choosing the right engine for your truck may seem like an easy task, but the model you choose can have a big impact on the work you do and the expenses you incur. If you still don’t know which engine is right for you, talk to your sales rep. Our team of new truck sales reps are trained to help you pick the model that will best suit the work you do.