I plugged my lawnmower into a Kill-A-Watt, and it drew ~13A on startup, but then ~4.1A continuous. (It is rated as a 12A motor, too -- but that doesn't mean it runs at 12A.) The total time was about 2 hours and 35 minutes, and I've misplaced the piece of paper I wrote it on; but the average was 0.38kWh per hour. And the mowing was anything but easy -- the grass was very thick and it was pretty tall.
Grid losses are no where near 50% -- I used to think this, but the EIA.gov figure is a national average of ~8% losses.
U.S. Energy Information Administration - EIA - Independent Statistics and Analysis I was told that number was on the site, but I have yet to find it, actually.
And again, the gasoline/diesel has all of this embedded in it; including the losses. So, an apples-to-apples comparison is that petroleum based fuel are far more energy intensive. It takes something 3-5 days to distill/refine gasoline, and the process requires lots of heat and power. If the electricity has been transmitted to the refinery, then you don't need to then subtract more energy just because you are going to use it in an EV.
We cannot reduce the BTU equivalency of electricity vs gasoline because of the embedded energy in just electricity. This would not be fair, and it is meaningless -- the energy equivalency is what it is: 33.4kWh per gallon of gasoline. And E85 is MPG x 1.41 = MPGe, and diesel is MPG x ~0.89-0.9 = MPGe (IIRC). These are equations, and they cannot be changed on one side without doing the same thing to the other side.
So, if you adjust for the embedded energy in electricity, then you have to do the same for gasoline. And the approximate balance is 40gm/km vs 450gm/km.