Chevrolet/GMC 6.6L L5P Duramax Radiator, 2017-2019

These Chevy L5P Duramaxes are designed for heavy-duty. It says so right on the badges stuck on the sides of the truck. GM did its best to prepare these trucks for the constant stress of heavy payloads and long hauls, but that still takes its toll on the cooling system. Luckily we have the perfect solution.

In our last post, we revealed GM's enormous factory radiator and covered the trouble spots. How do you improve on an already gigantic radiator? Make it even more gigantic-er.

Enhancing the size of this truck radiator was a tall order, given the lack of available space and tight build envelope. Even still, our engineer, Dan, was able to squeeze another 8mm of core thickness out of this design. Along with other core adjustments, we noted a 14% increase in core size, plus a 25% boost in coolant capacity. This might not sound like much, but every millimeter counts and can greatly increase cooling properties when it comes to managing heat. 

When you think of a heavy-duty truck, what comes to mind? It's a gigantic land ship that's capable of taking on every hauling or towing task that arises, right? Glad we're all on the same page. If we're honest, there's not really much disparity between that thought and real life. GM designed its 2017-2019 Silverado and Sierra HD Duramax to embody the essence of a workhorse, tackling every job without breaking a sweat. The trouble is, though, sometimes it will break a sweat, which is where we come in.

Before we dive into our design plans, we first need to look at the stock cooling system for the 6.6L L5P Duramax. The engineers at GM went big. Really big. Our initial reaction to this truck radiator was that it's huge. Then again, this isn't much of a surprise given the amount of work these trucks are designed to handle. From the factory, the L5P's radiator measures in at 33" x28" x2.4", making it one of the largest radiators we've extracted from a vehicle, and plenty of cooling power for