Gran Turismo 7 Update 1.55: New Cars, Sophy AI, and Physics Improvements

 There is currently no official or publicly available database for fuel efficiency across different cars in Gran Turismo.

To get meaningful fuel efficiency data, each car would have to be manually tested under controlled conditions. Just to give you an idea of the scale:

Gr.1 – 22 cars
Gr.2 – 10 cars
Gr.3 – 50 cars
Gr.4 – 33 cars
Total – 115 cars

If we assume 10–20 laps per car to get accurate data, and an average lap time of 1:30 minutes, testing just one class could take several hours, and testing all cars could take days.

On top of that, results can easily be skewed by small driving mistakes or variations in BOP updates (high-mid-low), so make all the test times 3. This makes creating a reliable fuel efficiency chart nearly impossible.

The only real way to get this information is through direct testing in your own race conditions, taking into account how you drive, how you shift, and what strategy you're using.