Loss of fuel mileage, my 2006 vibe has lost on average 5 mpg. on 2006 Pontiac Vibe

The vehicle does have just under 120k miles, was averaging 33 mpg just 8 months ago, and now get 28 mpg. The oil is changed every 3k miles, tires kept at proper psi, just had the transmission serviced.

1 answer
have you had a fuel line flush?