For engines where a fuel is burned there are two types of thermal efficiency : indicated thermal efficiency and brake thermal efficiency.
2.
Regarding brake thermal efficiency one study found that B40 was superior to traditional counterpart at higher compression ratios ( this higher brake thermal efficiency was recorded at compression ratios of 21 : 1 ).
3.
Regarding brake thermal efficiency one study found that B40 was superior to traditional counterpart at higher compression ratios ( this higher brake thermal efficiency was recorded at compression ratios of 21 : 1 ).