The most common and most likely answer to this crossword clue is the 8 letter word GASWORKS
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More clues leading to the result GASWORKS
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The straight part
We know that "fuel-making factory" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case fuel-making factory = gasworks.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does GASWORKS mean?
GASWORKS noun- A factory where coal is converted to coal gas and coke.