Oct 24 (Reuters) - The National Highway Traffic Safety

Administration said Friday is in contact about a new Tesla

driver assistance mode dubbed "Mad Max" that operates

at higher speeds than other versions.

Some drivers on social media report that Tesla vehicles

using the more aggressive version of its Full Self-Driving

system could operate above posted speed limits. NHTSA earlier

this month opened an investigation into 2.9 million Tesla

vehicles equipped with its FSD system over more than 50 reports

of traffic-safety violations and a series of crashes.

(Reporting by David Shepardson; Editing by Chizu Nomiyama )