Which option is a plausible indicator of increased fuel consumption due to over-throttle?

• A. Oil dilution
• B. Black smoke from exhaust
• C. Increased fuel consumption
• D. Engine overheating

Answer: (C)

When you open the throttle more than the engine needs for the current load, the fuel metering system sprays in more fuel to match the increased air, so the engine ends up consuming more fuel. That direct rise in fuel use is the clearest indicator that over-throttle is happening.

Why this fits best: increased fuel consumption is the direct consequence of driving the engine harder than required, so it naturally signals over-throttle.

The other options can be related to engine conditions but aren’t as direct a sign. Black smoke from the exhaust can indicate a rich fuel mixture, which might occur with over-fueling, but it’s more a symptom of combustion quality rather than a measurement of how much fuel is being used. Oil dilution points to fuel getting into the oil, a possible result of abnormal fuel delivery, but it doesn’t itself quantify fuel consumption. Engine overheating can happen under heavy throttle, but heat is influenced by cooling and load in multiple ways and doesn’t specifically indicate increased fuel use.

So the most straightforward indicator of increased fuel consumption due to over-throttle is the actual rise in fuel use itself.