I'm helping someone find a vehicle to purchase. They are only considering either a used Lincoln MKX or a Nautilus and no other brands like Cadillac or Lexus. Any reason to consider one of these engines over another other than horsepower? Ecoboost 2.0 or 2.3 4 cylinder FWD or Ecoboost 2.7 AWD. I know the MKX had a 3.7 NA V6 which I've read about the water pump going and cratering the engine. Are the All wheel drive systems fragile? Would the 3.7 NA be any more reliable than the Ecoboost? Do the Ecoboost Engines have a different water pump[ design? Are the old 6 speed transmissions more robust than the new 8 speed transmission? I'm looking to guide them toward less hassle and good reliability.