Calculating Efficiency of an Ottos Cycle: I Need Help!

[Kork]

I have made an Ottos Cycle graph and found the area W_net and W₁₂. I now have to find the efficiency η = W_net/W₁₂ I have found that to be 0,20 but I have no idea what this tells me about the work or anything.

I need help.

 

[eric2921]

If $\eta$=.2 then the system is 20% efficient, that is, if you put some energy into the system, only 20% of that energy is converted into work, and the other 80 percent is lost as heat.