U.S. safety regulators said on Friday they have opened an investigation into an estimated 50,415 newer Jeep Cherokee SUVs, a key model for the profitability of Fiat Chrysler Automobiles, after receiving complaints of engine compartment fires. The U.S. National Highway Traffic Safety Administration said it opened the preliminary evaluation into the 2015-model SUVs after a consumer from the San Diego area filed a complaint that their Jeep was "engulfed in flames approximately 20 feet high within seconds of parking the vehicle."