Humid air has less oxygen per unit of volume (i.e. less dense)
Water is 30% oxygen, air is ~16% ,IIRC.....therefore damp air contains more oxygen per unit volume than dry air....pedant mode off.
If we're talking about
available oxygen, that might be a bit different,- OTOH, water-injection has been used to boost engine power-output.
Forgot to mention....the remote central-locking on the Volvo Oh, and although the old B-type engines were thirsty, they have used Mitsubishi, Renault and Ford engines . A 1.7 Mitsu. Petrol will do 40+ mpg, the renault diesel around 50 mpg.......but they don't have the Q-car appeal of the "wolf in sheep's clothing.
