XN6guy, as much as it seems to go against common logic I am afraid that your first sentence is not correct.... and that PSFred is correct...gas has a lower energy density per unit of measurement....

The higher displacement comes partly as a result of the way in which the fuel is ignited, and that the higher the compression the more efficient the energy release is... that is the same as with gas engines.. except when you get to a certain point the lower flash point causes preignition in gas but not in diesel... (pre meaning before the proper piston position in the cycle ) ....

But we have strayed from the original question to where it looks like some of you are answering as if someone were Wanting to run gasoline ... and I have seen no indication on this post of that...

If a short period of running on gasoline did not produce noticable symptoms during or soon afterwards I say that the chances are that no harm was done....Lets try to help JimSmith sleep at night..... Greg