Car's tremendous feat when energy's added (5)
I believe the answer is:
coupe
'car's' is the definition.
(coupe is a kind of car)
'tremendous feat when energy's added' is the wordplay.
I cannot quite understand how this works, but
'feat' could be 'coup' (I've seen this in another clue) and 'coup' is located in the answer.
'when' could be 'e' (I've seen this in other clues) and 'e' is found in the answer.
This accounts for all the letters.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for coupe that I've seen before include "Car with just two doors and two front seats" , "Car with two front seats and a luggage compartment" , "Dessert dish" , "Car; dessert glass" , "Two-door car" .)