The Buick LaCrosse midsize sedan will get an updated and more powerful V6 engine for 2012. It will get a 23hp increase to 303hp and 264ft-lbs of torque, while retaining the previous V6's EPA fuel economy ratings of 17mpg city and 27mpg highway. Those figures are for the FWD LaCrosse; the AWD LaCrosse has not been rated by the SAE as of yet, but will also get a power increase.
The improvements to the 3.6L V6 come from a new cylinder head design, with revised intake ports, larger intake valves, and longer-duration intake camshafts. The cylinder heads also have integrated exhaust manifolds, which saves 13 pounds of weight, as well as a new composite intake manifold that cuts 5.5 pounds. Further weight shedding comes from lightened, high-strength connecting rods, bringing the total weight reduction to 20.5 pounds, and increasing the engine's balance and smoothness of operation.
GM global V6 chief engineer Tom Sutter said "We are using the latest designs, lighter-weight components and enhancements to improve the engine's performance, efficiency, and durability." As Buick is unique in that every new car it sells comes with direct injection, the new V6 will be direct-injected as well, but with a new, quieter fuel pump and isolated fuel rail. "The new 3.6L V6 offers 2012 LaCrosse buyers improved acceleration with no hit to fuel efficiency," said LaCrosse marketing manager Doug Osterhoff.
The Buick 3.6L V6 will also reduce hydrocarbon emissions by about 25 percent. It will be available as a no-cost option on higher LaCrosse trim levels as an alternative to the standard 2.4L with eAssist. It will become available later this summer as an early 2012 model.