the fuel cost for today trip cannot be reset even in a new day, it just keep accumulating. i am in China time zone, US time zone should be fine.
for example in the follow picture. I started in morning, the fuel consumed got reset, the distance today got reset, but the fule cost didn't. the fule price is 6.63 per liter here. the fuel consumed is 1.1l ,so the cost should be just 1.1*6.63 = 7.29, but it was 301.92.
it issue is still even I uninstalled and reinstalled Dashcommand.
this might be the same issue as I raised in link: http://www.palmerperformance.com/forum/index.php?topic=9424.0
in 2015. Distance and Fuel consumed got corrected that time but I didn't realized that fuel cost still had issue.