LS and LT

• The LS is the entry level version and shares the 3.6 liter, direct-injected, V-6 engine with the LT, its better equipped and more expensive sibling. The engine produces300 horsepower (hp) and 273 pound-feet of torque. Top speed in both models is electronically limited to 155 miles per hour (mph). The on-board computer reduces engine output, though does not shut off the engine, at this speed.
  
  

SS

• The SS is at the top of the model line and is powered by the far larger 6.2 liter LS3 V-8 engine. The engine makes 400 hp and 395 pound-feet of torque when mated with the six-speed automatic transmission. With a manual transmission, which can handle more power, output increases to 422 hp and 408 pound-feet of torque. However, this car, too, is electronically limited to 155 mph.
  
  

Rationale

• All models are limited to 155 mph, although they are perhaps capable of higher speeds, because of safety concerns. The tires on road legal cars are rarely safe at extreme speeds and even the limited performance of 155 mph is far above legal restrictions.