Agree, £10 fill-ups aren’t the best way to measure fuel consumption. Also, the car’s fuel computer won’t be 100% accurate. Filling the tank, refilling when it gets to somewhere between 1/4 full and empty and then calculating the consumption manually will give a better indication of the true fuel consumption, especially if done over 3-4 tank fulls of fuel. @Andy184; if your you’re running a diesel in mainly town / city driving conditions for short distances, you’ll be getting quite a few DPF regenerations - engine fan running and higher engine revs at idle being the tell tale signs. DPF’s will have a negative impact on your fuel consumption as the regeneration process uses extra fuel. Brand of tyres can also have a bearing on fuel consumption. I see that Hankook Ventus V12 Evo and V12 Evo 2 have an ‘E’ fuel efficiency rating. By way of comparison, Michelin PS4’s and Continental Sport Contact 5’s both have a ‘C’ fuel efficiency rating. Is the fuel consumption in the picture you’ve posted at the start of this thread representative of what you’ve always been getting or has it suddenly deteriorated? If the latter, has your journey type or time of day you travel changed, or are different drivers using your car that could explain an mpg change? Have you only recently had the Hankook Ventus tyres fitted? If so, what brand of tyres did you have previously? In your position, I’d fill the fuel tank to the brim and find a reason to take the car on some longer journeys to see how the fuel consumption changes (hopefully improves!) on longer journeys.