Bad fuel consumption

[Andre1981]

Hi there, hope everyone's having a great weekend. So I have the 200thp gt and use it as my daily drive. It runs fine, except for the little white smoke when i start due to the valve seals that needs to be replaced. I do push her hard and the power is there, but lately noticed that she is getting really bad fuel consumption. So i am getting 21 miles per gallon. Is this normal? If i drive it like its my in-laws i get best 25 miles per gallon. New filters new oil and new plugs has been fitted. I did a live data test on it and the fuel trim on bank 1&2 is 0.8 % with a 15 degree timing, this is all at idle. Also i have attached a few pictures of my inlet valves, could this make such a drastic difference in my fuel consumption? Thanks

 

[Marmite]

The Prince engine builds up carbon on the intake valves I heard walnut blasting may sort this problem , alas most direct injection engines suffer this problem what ever make