How boosting a diesel truck affects lubrication requirements

There is no doubt in my mind that many people struggle to
remember when diesel pickup trucks were slow, loud and boring to drive. We tend to forget things that aren’t exciting and replace those memories with more exciting ones. The addition of common-rail fuel injection systems in the early 2000s opened the door to exciting performance in diesel truck engines and create many
smiling faces driving millions of modern diesel trucks. However, happiness doesn’t always come without challenges.

The lube requirements for a diesel engine from 30 year ago and one manufactured today are vastly different. Rather than focusing on all the differences,
let’s consider how the turbocharger has changed lubrication for the better. Modern turbos are oil
lubricated, provide more boost
and can vary boost depending on vehicle speed. They’re much more complicated than a turbo from the 1990s with a simple waste gate. Let’s break this down into digestible pieces.

Today’s variable geometry turbo (VGT) provides a considerable amount of boost pressure. Compound that by adding electronic tuning devices that create even more boost, and it truly takes a toll on
your engine oil. More boost pressure equals more cylinder pressure, which results in more load on your pistons, rings, rods, crank and all the bearings in between. Engine oil lubricates and keeps all those metal parts separated. The more power the engine makes, the more load the engine oil needs to absorb.

This extreme load can be managed with more robust base oils and more technologically advanced additives, as found in AMSOIL Heavy-Duty Synthetic Diesel Oil and Signature Series Max-Duty Synthetic Diesel Oil. Modern chemistry advancements have allowed us to successfully lubricate diesel engines putting out more than 500 horsepower. That’s an enormous difference from diesel engines back in the 1980s that typically managed only about 120 horsepower.

Oil consumption and oil volatility have major effects on all components downstream of the combustion chamber. For the VGT to remain effective at varying boost pressure, the turbine vanes need to remain
movable. And since the first thing that partially burned oil touches is the turbine and its movable vanes, it can present deposits that render the variable function of the turbo useless. Using high-quality base oils reduces the opportunity for oil in the sump
to find its way outside the engine. Reducing oil consumption is not only good for protecting your turbo and
downstream exhaust after
treatment systems, but also for protecting your wallet.

Finally, one cannot build engines making immense power without managing the incredible heat generated. It doesn’t help that original
equipment manufacturers (OEMs) have intentionally increased heat in the engine because they’ve found that it improves engine efficiency. Modern diesel engines like to run at about 200°F (93°C) and sometimes hotter, depending

on load, which means oil temperatures can easily reach 250°F (121°C) inside the engine.

The bearing of the turbo is engine oil lubricated. It’s small, with tight clearances and a shaft that spins at incredible speed, so high quality, clean oil is imperative to its continued operation. To solve all these problems, base oils that remain stable at higher temperatures, detergents that keep surfaces clean and antioxidants that maintain viscosity over the oil’s entire service life are all formulated into AMSOIL synthetic diesel oils.Although many vehicles still use 15W-40, other viscosities have really been gaining momentum, so AMSOIL offers Signature Series Max-Duty Synthetic Diesel Oil in five different viscosities. If you want to give your turbo the best chance at a long and healthy life, make sure you only use the best-quality AMSOIL diesel oils. Your turbodiesel will thank you.