Purchased the car as a lease buy back. Hwy mileage was 40mpg + from purchase date I had the engine light come on every couple weeks (emission problems) indicating a leak in the emission system. On warranty they changed every sensor, hose, filter, the fuel pump, even the gas cap. The mileage was still good but the light would still come on and the computer showed emission leak problem. Finally they changed the fuel tank. This solved the problem. Thats when the mileage started to drop and has been getting worse. My last hwy trip I had 278 km on a tank full. The dealership told me it needed a complete tune up. plugs, filters, and injector cleaner. I have always added injector cleaner every 6 tanks of fuel. Nothing helped. They now tell me I should change injectors but can't guarantee it will help. It starts & runs great. I don't think thats the problem.