Gran Turismo 7: How to complete the Moby Dick Eco-Challenge mission

Before you begin the Moby Dick Eco-Challenge task in Gran Turismo 7, go to Settings, then Display Settings, and make sure Show Race Info is set to "Display All" under Race Display. Then, while you're still stationary on the grid before the mission begins, hit the D-pad once to the left to bring up the Fuel Map in the bottom-right corner. While you're still standing still, tap up three times on the D-pad to change the Fuel Map to 4.

Now drive as quickly as you can around the Tsukuba Circuit. Because the Toyota 2000GT '67 is an old, light car with rear-wheel drive and no tuning parts, it is prone to oversteer. Make sure you use the accelerator with care, especially while exiting those hairpins. Tap the D-pad once just before entering the third and final hairpin to set the Fuel Map to 3.

This should ensure that you get the most mileage out of your fuel for the long straight and final bend. It's best if you cross the line just as your fuel runs out. Your GT7 driving skills will determine your grade, but this advice should be sufficient to earn you a Bronze.