Imperial gallons in car setup, US gallons in HUD?

So I'm driving a WTCC 17 Chevy.

I go into the car setup and put a full tank of gas in, 8.8 gallons.

I get into the car and the dash/HUD says 10.6 gallons.

I'm assuming that as 1 imperial gallon = 1.2 US gallons, the American car I'm driving is displaying US gallons, but the setup screen coded by a Swedish company is using imperial gallons.

Can anyone confirm/deny?

 

hud as the cars dash or an addon display hud ?
if so which one

Andi

 

Car's dash (i.e .the digital readout on the in-cockpit wheel), as well as the HUD (i.e. the number next to the little gas pump icon), which both show the same number (10.6 gallons for a full tank)

I'm not using any addons.

 

ok , will ask

Andi