Roush Performance has introduced a pair of new 540hp Mustangs – one wild, the other mild. 

The 2010 Roush Stage 3 Mustang once again takes its rightful place atop the hierarchy of Jack Roush’s lineup. The Stage 3 comes loaded with Roush body components, resonator exhaust, four-piston front brakes with 14-inch rotors and painted rear calipers with slotted rotors, and a new upper billet grille which removes the fog lamps and streamlines the Mustang’s appearance while improving cooling performance.

Interior enhancements include Roush leather seats with an embroidered Jack Roush signature, four-piece performance pedals, Roush illuminated sill plates, short-throw shifter with black or white ball, and a new interior Stage 3 badge with the car’s serial number engraved.

The new Stage 3 Mustang rides on 18-inch chrome wheels with high-performance Cooper RS3 tires; 20-inch chrome wheels are one of the available options. The suspension package includes Roush front struts, rear shocks, front and rear springs, front and rear stabilizer bars, and jounce bumpers.

“The Roush Stage 3 Mustang has traditionally been among the halo vehicles of our lineup and I’m really proud that it sits atop the pecking order once again,” said Jack Roush. “This new iteration of the Stage 3 represents our highest horsepower and most sophisticated Roush Mustang yet.”

The second Mustang is something new from Roush. Designed as a “sleeper,” the 2010 Roush 540RH contains limited content but a full 540hp powertrain. “It’s really intended to be a ‘sleeper’ car,” Roush explained. “It will be built with minimal content as it was designed for the buyer who wants the Roush horsepower but with a blank canvas that can be customized into their own personal one-of-a-kind ride.”

Also known as the Hammer, the 540RH is armed with massive horsepower, a Roush rear spoiler, and a short-throw shifter with a choice of white or black ball. A new suspension package includes front and rear springs, front and rear stabilizer bars, and subtle tone-on-tone striping.

Proving just how quick this car can be on the optional 18-inch Cooper RS3 tires, Roush engineers recorded an 11.8-second elapsed time at 121 mph during testing at Milan Dragway.

The 2010 Stage 3 and 540RH Mustangs use the same engine that debuted in the ’09 Roush P-51B Mustang. In order to get this type of power from the Ford 4.6L, 3-valve engine, Roush technicians replace many of the internal components with stronger parts, including forged aluminum pistons (with an increased dish to lower the compression ratio from 9.8 to 8.6), forged steel H-Beam connecting rods, and a forged steel crankshaft. The fuel rails are changed, as are the fuel injectors and an upgraded fuel pump. Roush also upgrades the clutch and includes a custom-calibration for the ECM to manage the performance of the next-generation R2300 Roushcharger.

Suggested retail price for the Roush 540RH is $46,145 when built on a base Ford Mustang GT chassis. The limited-production Stage 3 Mustang retails for $59,945. Only 103 will be built.

Both vehicles are covered by a 3-year/36,000-mile warranty and will be available with a manual transmission only. For more information on either of these new models, or to see the complete content list, visit http://www.roushperformance.com/.