postwar fuel costs - piston v turbine

[Cromard]

in a recent UK tv programme someone fleetingly mentioned lower fuel costs helping the Viscount
the UK has traditionally had very high tax on Avgas & petrol/gasoline, but no ? tax on paraffin/kerosene (the taxman has no info before 74)
I assume this was a major factor acting in favour or jet & propjet sales, and against piston-engined competitors
can anyone give clarification on this ?

[avionic type]

Costs
The Aero piston engine was a highly complex unit even a new one used oil in large quantities as they leaked like sieves leaving puddles on the floor and filthy to boot plus a multitude of spark plugs and ignition harness to go with them and had a short overhaul life in100s of hours and expensive in man hours to maintain , where as the jet was very clean used hardly any oil were only fitted with 2 ignitor plugs Avtur [low grade paraffin ]was a lot cheaper less volatile and and safer ,after a few years had an overhaul life measured in 1000s of hours and were cheaper to maintain,also they were much lighter in weight.