Intake Scoops. Do they actually work?

Do Intake Scoops Reduce Air Temperature and Improve Performance?

If you’re looking for a simple, effective upgrade for a naturally aspirated engine, intake scoops are often overlooked. However, real-world data shows they can actually make a measurable difference.

What Do Intake Scoops Actually Do?

Intake scoops help direct cooler ambient air toward the intake system. Without them, the engine tends to draw warmer air from the engine bay, especially at lower speeds or during repeated acceleration.

By improving airflow and reducing heat soak, scoops ensure that the intake system receives cooler, denser air.

Real-World Test Data

To evaluate their effectiveness, intake air temperatures (IAT) were measured under three conditions with ambient temp 15°C:

• City driving (50 km/h)
• Cruising (100 km/h)
• Wide open throttle (WOT) during spirited driving on B roads

Results:

Temperature Reduction

Across all driving conditions, intake scoops consistently reduced air temperature:

• Up to -14 °C during cruising
• Around -11 °C at WOT
• Roughly -10 °C even during city driving

This shows that not only the scoops actually have a significant impact, the effect is also not limited to high-speed airflow, but also helps mitigate heat buildup in everyday driving at lower speeds. 

Why Cooler Air Means More Power

Engine performance is directly influenced by air density. Cooler air is denser, meaning it contains more oxygen per unit volume. This allows the engine to burn fuel more efficiently, resulting in increased power output.

A commonly accepted rule of thumb:

• Every 5 °C drop in intake temperature ≈ 1 % increase in power

Estimated Performance Gains

Using the measured WOT data:

• Temperature drop: 40 °C → 29 °C (-11 °C) temperature decreased by 27.5%.
• Estimated gain: ~2–2.5% more power

For a 110 kW (150 hp) engine, this translates to:

• Approximately +2 to +3 kW
• Roughly +3 to +4 horsepower

Real-World Driving Benefits

So what does all this technical stuff mean for your real-world driving? Beyond peak numbers, the improvement is noticeable in:

• More responsive throttle
• Reduced heat soak during repeated acceleration
• More consistent performance under load

This is especially relevant for spirited driving, where intake temperatures can quickly rise without proper airflow.

Conclusion

Intake scoops are a simple, low-cost modification that delivers measurable results. While the raw power gains may seem modest on paper, the overall improvement in consistency, responsiveness, and thermal management makes them a worthwhile upgrade for the ST150.

In a world where many modifications promise gains but deliver little, this is one of the rare upgrades that can be both measured and felt especially on warm summer days.

Upper intake scoop

Lower intake scoop

*If you’re based in the UK, you can purchase this product via retrofastfords.co.uk.