The aluminum-block power plant — standard in coupe and convertible — produces an SAE-certified 430 horsepower @ 5900 rpm and 424 lb.-ft. of torque @ 4600 rpm. Power output is even higher with the available dual-mode exhaust system with 436 hp @ 5900 rpm and 428 lb.-ft. of torque @ 4600 rpm. Yet the LS3 6.2L engine achieves a remarkable EPA estimated MPG 16 city, 26 highway with the standard six-speed manual transmission. Even with its impressive performance, the engine does not incur a federal government gas-guzzler penalty.