Sid Lee needs an oil change (6)
I believe the answer is:
diesel
'an oil change' is the definition.
The answer and definition can be both man-made objects as well as being singular nouns.
Maybe there's an association between them I don't understand?
'sid lee' is the wordplay.
'sid lee' anagrams to 'DIESEL'.
But, I'm unsure how this is indicated.
'needs' is the link.
Can you help me to learn more?
(Other definitions for diesel that I've seen before include "Common fuel for heavy vehicles" , "Fuel used by heavy vehicles" , "Fuel for heavy vehicles like lorries" , "See lid, oddly, of the fuel" , "Type of fuel oil" .)