Most Audi A4s in the UK are probably the 2 litre inline 4 diesel. See the specs page here: http://www.audi.co.uk/new-cars/a4/a4-saloon/specifications.h.... Note that figures are in miles per Imperial gallon. The EU tests can produce unrealistic results, but the combined figure is usually actually attainable in practice under realistic conditions.

58.9 miles per imperial gallon in miles per 16.1 US gallons = 789.6 miles.

Diesel fuel is denser, but it comes out of the pump just as quickly. Add perhaps 20 seconds for donning and discarding your disposable gloves.

N.B., the Tesla probably accelerates better and with less noise than the 2L diesel. But that said, for the cost of a Tesla, you could probably buy an Audi A4 and run it for 25 years (in the rather unlikely event your car search has narrowed itself down to exactly these two types of car).