Big vehicle? Millions in fuel, on reflection (4)
I believe the answer is:
limo
'big vehicle?' is the definition.
'limo' can be an answer for 'vehicle?' (limo is a kind of vehicle). I'm not sure about the 'big' bit.
'millions in fuel on reflection' is the wordplay.
'millions' becomes 'm' (abbreviation for millions).
'in' means one lot of letters goes inside another.
'fuel' becomes 'oil' (oil is a type of fuel).
'on reflection' says the letters should be written in reverse.
'm' placed inside 'oil' is 'omil'.
'omil' backwards is 'LIMO'.
Can you help me to learn more?
(Other definitions for limo that I've seen before include "Set of rooms" , "vehicle" , "Luxury car" , "Stretched car, often used for partying" , "Luxurious car (colloq.)" .)