Petrol or Diesel?

Accurate figures are hard to come by, but my best estimate is that diesel cars account for around 50% of the car market at present and that share is increasing. Some time ago I read an article about the contents of a barrel of oil and the figures are as follows:

Product Gallons Percentage
gasoline 19.5 44.12%
distillate fuel oil (Includes home heating oil and diesel fuel) 9.2 20.81%
kerosene-type jet fuel 4.1 9.28%
residual fuel oil (Heavy oils used as fuels in industry,
marine transportation and for electric power generation)
2.3 5.20%
liquefied refinery gasses 1.9 4.30%
still gas 1.9 4.30%
coke 1.8 4.07%
asphalt and road oil 1.3 2.94%
petrochemical feedstocks 1.2 2.71%
lubricants 0.5 1.13%
kerosene 0.2 0.45%
other 0.3 0.68%

Discounting the differences in fuel consumption between the two engine types I think that there is a glaring anomaly here. We are producing twice as much petrol as diesel for the same number of vehicles of each type, so the question is: How is it accounted for, where is all the surplus petrol going?

I understand that there are far too many variables to grapple with, and that a barrel of oil varies in consistency and content depending on its geographical area of production but I don’t understand why there is no information available for the discrepancies. Note also that the “Distillate Fuel Oil” covers heating oils too, so there is a bigger difference.

Over time I have remarked upon this to various people but no credible answer has been given…. Can you help?