Related: Automotive Powertrain
“When we started planning to equip this vehicle with the 3.6-liter engine, I challenged our engineers to achieve fuel efficiency.” That’s Liz Pilibosian, vehicle chief engineer for the 2012 Cadillac SRX. The engine in question—code-named LFX—is the only engine available in the new SRX. “They came back and exceeded the goal with 308 hp.”
The 60° V6 engine produces 308 hp @ 6,800 rpm and 265 lb-ft of torque @ 2,400 rpm. It delivers an estimated 17/24 city/highway EPA mpg. (It is mated to a Hydra-Matic 6T70 six-speed automatic transmission.)
Here are some aspects of this engine:
• Lightweight aluminum block and heads
• Four valves per cylinder, and dual overhead cams with infinitely variable cam phasing
• Forged steel crankshaft
• Powdered metal connecting rods
• Composite intake manifold (said to be 5.5 lb lighter than a comparable aluminum manifold)
• Integrated cylinder head/exhaust manifold design (saves 13 lb vs. an engine with separate head/manifold assemblies
• Cast aluminum pistons with polymer-coated skirts
• Cast aluminum oil pan
Steve Kline, lead development engineer, said that the exhaust system is “all new from the engine to the exhaust outlets. From larger diameter pipes to a higher-volume muffler, the system is tuned to pull exhaust gas out of the engine at 1,200 to 3,000 rpm. This means more torque when you need it most.”
And speaking of the airflow, Pilibosian said, “The exceptional airflow qualities enabled us to exceed the 300-hp target, while careful calibration of the dual continuously variable valve timing system and the exhaust system contribute to the engine’s great low-end torque.”
LFX engine is a global product, as it is produced by GM in its plants in Flint, MI, St. Catharines, Ontario, and Melbourne, Australia.
The LFX 3.6-liter direct-injected V6 for the 2012 Cadillac SRX provides 308 hp and 265 lb-ft of torque.