Test old bag maybe for fuel (7,3)

I believe the answer is:

bottled gas

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'fuel' is the definition.
The answer and definition can be both substances as well as being singular nouns.
Maybe there's an association between them I don't understand?

'test old bag maybe' is the wordplay.
'maybe' indicates an anagram.
'test'+'old'+'bag'='testoldbag'
'testoldbag' with letters rearranged gives 'BOTTLED GAS'.

'for' acts as a link.

Can you help me to learn more?

I've seen this clue in the Sydney Morning Herald.

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