As much as we like the 5.9L Cummins powerplant, the stock exhaust manifold is constrictive and contorted, interfering with the flow of gases to the turbo and downpipe. That, in turn, can produce the ...

Since this Cummins doesn’t have a throttle valve on the intake (like most gasoline engines), there is little engine braking or negative torque created by the crankshaft. This is because the ...

Cummins released details of its 2027 X15 diesel engine, which it says meets EPA 2027 emissions requirements while improving fuel economy — and without adding weight or using more diesel exhaust fluid.