It's a Mustang dyno and they always read low on us on HP/TQ numbers. Plus you have take his elevation into account as well depending on what that is just like when you drag race. I saw an 12 Jeep SRT8 only put down 325Hp on a mustang dyno in Denver Colorado(on TV) and they were saying that it was due to the elevation and it being a Mustang dyno as to why it didn't put down more.
Approximately 3% for every 1000 ft above sea level, give or take
2012 Stinger Yellow SuperBee - Trinity; HID's; 4.3S Stereo; Flowmaster Outlaws; Black MSRT rims; BC Coilovers; Roof Spoiler; Tinted Tails/Windows; 3.92 (Soon: ZT-3, Hood, Scoops)
2007 Sublime Daytona #82/150 - Predator; VFN AAR hood; OBX LT's/Super 44's; Painted/tinted tails; Martin Bros 940's
2005 Cool Vanilla Magnum - Sold
2011 GWE Challenger R/T Classic 6-speed - Traded
2009 Hemi Orange SuperBee #178/425 - Traded
2006 Silver Steel R/T R&T - Traded