firestone said they recommend it. for i has less then 40,000 miles on it and change the oil every 3,000 miles and rotated my tires already. for it's been sputtering in the a.m. and feels like it's going to counk out and the enegine light comes on but the handbook said it maybe becuz gas cap not on tight..check that and ok. gas might be bad?! could i do the fuel tune up myself and save money here?!?