Acceleration And Oil Consumption Problem

[anons]

Recently i found my IS300 (2009modle,40000km now) acceleration was so disappointed me, the car was not much moving even i push the accelerator hard, (it was like lag for two to three seconds) and the oil consumption was high, normally it was 12.3L/100km, now it was 15L/100km(city drive). So i back to dealer, they did a computer check, said sth fuel consumption date the "long shot 1 is -6%, the longshot2 is -6.5%" normal date should be both positive . they told me that its because fuel quality i used was not good , advised me to change other gas sational, i did, but i did not gave a better performance. could anyone advise me. should i change my fuel fillter? or it might be the fuel injection systme go wrong? thanks a lot....