i wish i got 30 on the highway again. too many hills and what not, seafoam helped with the slight power loss that was felt, and i totally need engine mounts and suspension! so lately my car has been averaging around 16.2 with about 6 miles of hiway and 2 miles light to light. if i drive the car more than say 10 miles on freeway it gets around 19. front o2 a little off?