Renntech has been known for performing great work on Mercedes-Benz, and with their take on the CLS63 AMG, they stepped their game up to another level and pitted it against the notorious 2012 Nissan GT-R on the drag strip. The 2012 Mercedes CLS63 AMG runs on a 5.5-liter twin-turbocharged V8 that packs a serious output of 518hp and 516lb-ft of torque. Renntech then added a new exhaust system and an effective ECU software upgrade for a seriously boosted output of 669hp and 734lb-ft of torque.

Performance numbers for the Benz have increased greatly, hitting 60mph from rest in only 3.4 seconds. Renntech was so confident in their work that they took it down to the Palm Beach International Raceway and pitted it against the drag strip specialist 2012 Nissan GT-R.

The most impressive thing about the American's tuning job? This is only their Stage 1 package. The Renntech Stage 1 package for the 2012 Mercedes-Benz CLS 63 AMG ran the quarter-mile in 11.21 seconds and was measured at 126mph. Pricing is set at $3,495.