My buddy just bought a 2002 Ford F150 with the 4.6 engine and 15,000 miles on it. The owners book says to use Motorcraft 5w20 synthetic blend. Is there a better oil for his truck then this? He has a Fram oil filter on it now and told him to not use those anymore but I'm not sure what the best oil would be for him. He won't change it himself and takes it to the local Firestone garage to have his cars serviced. Many thanks!