The most common and most likely answer to this crossword clue is the 6 letter word DIESEL
I've seen this crossword clue in The Times
D
I
E
S
E
L
More clues leading to the result DIESEL
- Occasionally driver steals fuel
- Engine driver stops working with European line
- Pass market that has one pound off oil
- Polluting car stops working with just half of fuel
- Type of train exits eastern line
- Type of fuel ceases to work well, oddly deficient
- Passes on the Spanish fuel
- Chicago train conks out first – has this run out?
- Rudolf, the German behind something energising locomotives to begin with?
- Fuel runs out before rival ends
Buddy explains!

The straight part
We know that "Engine driver" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case engine driver = diesel.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 DIESEL mean?
DIESEL noun- A fuel derived from petroleum (or other oils) but heavier than gasoline/petrol. Used to power diesel engines which burn this fuel using the heat produced when air is compressed.
- A vehicle powered by a diesel engine.
- A rider who has an even energy output, without bursts of speed.
- Snakebite and black (a drink).
- A particular cannabis hybrid.
- To ignite a substance by using the heat generated by compression
- For a spark-ignition internal combustion engine to continue running after the electrical current to the spark plugs has been turned off. This occurs when there's enough heat in the combustion chamber to ignite the air and fuel mixture without a spark, the same way that heat and pressure cause ignition in a diesel engine.