Real top-class engine needs overhaul (7)
I believe the answer is:
genuine
'real' is the definition.
(I know that real can be written as genuine)
'top-class engine needs overhaul' is the wordplay.
I cannot quite understand how this works, but
'top-class' could be 'u' (as in U and non-U speech) and 'u' is located in the answer.
an anagram of 'engine' is 'genine' which is within the left over letters.
This accounts for all the letters.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for genuine that I've seen before include "Real, true" , "Real, not faked" , "Not fake or counterfeit" , "Ingenue - the real McCoy" , "Native" .)