The Challenger 850 has undergone many design modifications from the former airliner. This includes steel brakes in the place of carbon, computer-controlled fly-by-wire system, and single point and over-fueling. By redesigning its airframe, the 850 ELR can carry an additional 4,000 lbs of fuel than its predecessor, increasing payload, range, and takeoff weight. The 850 can travel at .85 Mach and reach a certified flight ceiling of 41,000 feet. During the climb, it takes a relatively quick 32 minutes to reach 37,000 feet. Its maximum takeoff weight is 53,000 lbs.