How many joules in 1 liter diesel?

0.836 litres

Recalculated.

1 litre of diesel weights approx 820 grams (ie SG .82) therefore 1KG is approx 1/.82 or 1.22 Litres.

Diesel floats on water therefore it's SG must be less than 1 therefore there must be more than 1 litre of diesel per KG.