These Trucks Still Use Pushrod Engines, And There's A Good Reason Why

Pushrod engines may not be as popular as they used to be, but to paraphrase the old Mark Twain misquote, "The reports of its death are greatly exaggerated." In fact, GM recently announced it was investing $888 million in its Tonawanda Propulsion Plant to help build the sixth generation of its small-block V8, and all signs point to it being another pushrod powerplant. After all, pushrod valve actuation has been a core feature of the General's small-block V8s since they were introduced in 1955, and that's unlikely to change.

The 2025 Chevrolet Silverado and GMC Sierra 1500 trucks use 5.3- and 6.2-liter V8 gas motors with pushrods, while 6.6-liter gas and diesel pushrod V8s can be found in the 2500/3500 weight class. Other domestics use pushrods for both fuel types, too. For the Ford Super Duty, there are 6.8- and 7.3-liter gas engines or a 6.7-liter diesel, both V8s. The final member of the Big Three can ante up with a 6.4 gasoline V8since the 2025 Ram Heavy Duty trucks keep the Hemi's pushrod design. In addition, Ram teams up with Cummins on a 6.7 liter pushrod I6 for its HD entries, and the 2026 Ram 1500 brings back the Hemi V8 as well.

Still, it's not just tradition that's driving the commitment to old-school technology. There's a good reason trucks with pushrod engines are in production — they have key advantages truck owners love.

To understand the pushrod advantage, you have to first understand how pushrod engines work. Nearly all internal combustion engines today adjust how fuel and air enters the engine, along with how exhaust gases leave, by using valves in the cylinder. A camshaft "tells" the valves when to open and close by physically changing their positions. In a pushrod engine, the camshaft is in the engine block itself while the valves are some distance away in the cylinder heads. Pushrods and rocker arms come into play to transfer the spinning motion of the camshaft, itself caused by the crankshaft, into the up and down motion of the valves.

Overhead cam engines, unsurprisingly, mount their camshafts above the engine block where they're much closer to the valves in the cylinder heads. As a result, they can do without the long and relatively heavy pushrods to manipulate the valves, relying instead on small components called tappets or valve followers. On the other hand, their positioning means they require a more complicated system for connecting the camshaft and crankshaft. It's a small difference that can have a big effect on performance.

The simpler, more compact packaging — with camshafts integrated into the engine block instead of piled up on top — is one important factor behind why trucks still use pushrod engines. It translates into lighter, smaller engines that are also less expensive to build and maintain than OHC motors. This is particularly noticeable when it comes to timing. The distance between the camshaft and crankshaft in OHC engines requires a longer, more complicated mechanism for the timing belt or chain that connects the shafts.

Pushrod engines can additionally deliver output and efficiency benefits over their OHC counterparts. Generally speaking, the design of pushrod engines allows for better airflow, allowing them to make more power with fewer rpm, and the fact that they're not working as hard improves fuel economy. Needless to say, those are great characteristics for hard-working truck engines.

The flipside to this is a literal inability to rev as high as OHC engines. The extra weight of the pushrods and rocker arms, compared to tappets with overhead cams, physically limit how fast the engine can revolve before the valves get out of sync. As a result, pushrod engines aren't as suitable for high-rev applications.

On the other hand, pushrod engines remain on the menu for some notable high-performance sports cars. Even though the 2026 Chevrolet Corvette's redesigned interior shows how it's still evolving, it still comes standard with a 495-horsepower pushrod V8 that's certainly no pushover.