<Li> Heat in (Q i n (\ displaystyle Q_ (in))) is done by the combustion of the fuel </Li> <Li> Work out (W o u t (\ displaystyle W_ (out))) is done by the working fluid expanding and pushing a piston (this produces usable work) </Li> <Li> Heat out (Q o u t (\ displaystyle Q_ (out))) is done by venting the air </Li> <Li> Net work produced = Q i n (\ displaystyle Q_ (in)) - Q o u t (\ displaystyle Q_ (out)) </Li>

Otto cycle and diesel cycle in marine engines