The 2021 Cadillac CT4 with the optional 2.7-liter engine uses the exact same L3B engine originally designed and engineered for the Chevrolet Silverado pickup trucks. The turbocharged four-cylinder engine produces 310 horsepower and 350 pound-feet of torque.
In the CT4 its rated at 21 mpg city, 31 mpg highway and 25 mpg combined. Unlike the Chevrolet Silverado which comes with an 8-speed automatic the CT4 comes with GM and Ford’s joint-venture 10-speed automatic.
The engine which is built in Spring Hill, TN because of its displacement and truck duty intentions is very large and robust in its physical stature with an aluminum block and head. Make no mistake, it’s an engine with the latest technology and high feature content.
Following the airflow, the intake charge starts up front on the passenger side at the large air-filter box and then flows straight into a dual volute BorgWarner turbocharger that provides up to 22psi boost with the help of a computer controlled electronic wastegate.
Air then travels down to the lower front to an air-to-air intercooler behind the front fascia and then back up to the driver side of the engine to a composite plastic intake manifold. The engine breathes through a 16-valve head with dual cams and full variable cam timing and variable valve lift.
Featuring direct-injection the engine also has active fuel management which can disable its two center cylinders to save fuel when coasting or running at a constant speed. To keep all of this rotating and operating in a refined manner there are also two balance shafts.
Looking around the engine bay with an eye for maintenance, the first thing of note is that a few tools are required to change out the air filter as it uses screws instead of pop clips to open up the box. The oil filler cap on the other hand is right up front at the top of the engine. The oil filter is accessible from below.
To the passenger side on top of the engine you will find the oil dipstick and further behind it at the driver side of the firewall is the brake fluid reservoir. On the opposite side of the firewall is the main reservoir for engine coolant. Just aside it with a hard to see black cap is the windshield washer fluid.
The 12-volt battery is located in the trunk space under the liner at the driver side. In the engine bay however you will find a jumping post clearly marked. Next to it is the main consumer grade fuse panel with an included fuse removal tool you will need when changing them out.
The engine compartment itself is laid out with reasonable space to work. Noted are its more expensive and exotically constructed cast shock towers and cross bracing for a tighter and lighter chassis overall.