The Diesel Performance Trifecta

Diesel Pro Erik Miller Reveals the Diesel Performance Trifecta

By Erik Miller, ​​DMAXstore

Photo: ​Josh Lawler​

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There’s no lack of aftermarket parts and accessories for diesels making big promises. But diesel performance doesn’t need to be complicated. There are three essential areas any diesel owner should look at to get the most out of their engine; the fuel system, the air intake, and the exhaust system. Together, these three form the performance trifecta.​

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#1 The Fuel System

Modern diesel common rail high pressure systems have some great advantages and a few drawbacks. Some of the awesome benefits include better atomization of fuel, multiple injection events per stroke, and increased fuel economy. But there’s one thing you need to know. These systems don’t only use fuel to power the engine— it’s also used to cool and lubricate fuel system components.

Since around 2006, standard #2 diesel fuel has lost some of its lubricating quality due to reduced sulfur content. Sulfur itself isn’t a lubricant, but the process used to remove the sulfur reduces the diesel’s lubricating properties.

So why does this matter? Well for one, the fuel system is home to some expensive replacement parts, so it’s important to know how to keep your fuel system healthy.

There are two things you can do to optimize your fuel system that require no mechanical skills whatsoever. First off, make sure to use quality fuel. Most of the normal #2 diesel you get at the pump is the same from station to station (and yes, you want to avoid those rusty old farm tanks!). But there is a better quality product on the market; Propel’s Diesel HPR.

Diesel HPR has qualities that all diesel fuels should have; higher lubricity, higher cetane, and lower overall emissions. All of these properties enhance the performance of your diesel engine. We’ll take a closer look at why in future posts, but for now, just trust me (and my 25 years of experience).

My second fuel system tip is to use a fuel additive every few fill ups or so. There are different kinds of additives depending on what you’re looking for— some increase the lubricity, some boost cetane, and some reduce gelling. If you are using #2 diesel I always recommend adding at least a lubricity additive.

“Diesel HPR has qualities that all diesel fuels should have; higher lubricity, higher cetane, and lower emissions.”
Erik Miller

#2 Air Intake and #3 Exhaust Systems

Air intake and exhaust are a little more straightforward. I group them together for a reason; the internal combustion engine is an air pump. It draws air in and blows it out, so the less work the engine has to do to move that air, the more efficiently it runs. And better efficiency results in more power and better fuel economy.

Compared to the fuel system, intake and exhaust upgrades are more expensive to install. There’s a lot of options to fit budgets and objectives of all shapes and sizes, but for your average weekend wrencher, improved efficiency can be achieved just by regularly replacing the air filter. You could also try a new high flow drop-in filter, or, if you’re feeling ambitious, you could install an aftermarket air intake system.

The exhaust systems job is getting air out, which is the third piece of the performance trifecta. There are some key things to consider when optimizing your exhaust system.

Make sure to identify your exhaust emissions and determine what type of exhaust note you are looking for. For some diesels built around 2000, a complete high flow turbo back system can be installed, since some vehicles around this time were built without catalytic converters.

Even newer diesels with catalytic converters can still benefit from a “cat back” high flow exhaust, or even a “DPF back” exhaust system with wider piping diameter. “Cat back” exhaust is installed behind the catalytic converter, and “DPF back is installed after the diesel particulate filter (DPF).

It’s pretty amazing how restrictive factory installed mufflers and exhaust piping can be. Exhaust upgrades can reduce back pressure, improve exhaust efficiency, and increase MPG and horsepower, and if running Diesel HPR, reduce emissions as well.

Check out these three components of your system first, and you’ll be off to a good start. As you learn more about your engine and how to maximize its performance, you’ll get hooked on making it better! Feel free to reach out if you need a hand.

Erik Miller


I started my professional automotive career in 1991, working at two of the largest Chevy dealers in the Sacramento area from 1991 to 2012. During this time, I was a Dealership Foreman and helped develop a transmission education program for a local college. I enjoy working in and understanding all areas of auto repair.

With time, I was drawn to two types OFX vehicles— diesels and Corvettes. I ended up a little obsessed with both, and spent some time at a Corvette performance and restoration shop. I’ve been with DMAXstore for the last 5 years doing diagnostics, repairs, and custom work.

The fact that DMAXstore works exclusively with Duramax diesels has allowed me to completely immerse myself in the diesel industry. I currently drive a 2006 Silverado Duramax and my son drives a 2003 GMC Sierra Duramax. I just purchased a 2015 GMC Denali dually (also a Duramax), and I’m also working on a long-term 1964 Buick Skylark Duramax project. I think you can see my obsession!