how to rev a car engine

[MacDaisy]

Revving a car engine means increasing its speed while the vehicle is in Neutral or Park, causing the RPM (Revolutions Per Minute) to rise without the car moving. It's done to warm up the engine, check performance, or simply for auditory effect, but it must be done correctly to avoid engine damage. Modern engines with electronic fuel injection require little to no warm-up idling, making revving largely unnecessary for daily driving.

The correct procedure is simple. First, ensure the car is in Park (for automatics) or Neutral (for manuals) with the parking brake firmly engaged. Never rev the engine in Drive or Reverse. With your foot firmly on the brake, press the accelerator pedal smoothly and briefly. Avoid "redlining," which is pushing the RPM gauge into the red zone near its maximum. This can cause immediate and severe damage to internal components like pistons and valves. For a quick check, a short, smooth press to around 2,000-3,000 RPM is sufficient.

There are significant risks, especially with a cold engine. When an engine is cold, oil is thicker and hasn't fully circulated, leading to increased metal-on-metal wear. Excessive revving accelerates this wear. Furthermore, it wastes fuel and can be a nuisance, potentially violating local noise ordinances. It's a practice best used sparingly and with mechanical sympathy.

The following table outlines RPM ranges and their typical purposes or risks:

RPM Range	Purpose / Implication	Risk Level
Idle (600-900 RPM)	Normal stationary operation; warming up.	None
1,500 - 3,000 RPM	Gentle warm-up; checking throttle response.	Low
3,000 - 5,000 RPM	Performance checking; loud exhaust sound.	Moderate
5,000 - Redline	High-performance testing (on a fully warmed engine).	High
Redline+	Exceeding engine's designed maximum speed.	Severe (Engine Damage)

[SanCarter]

Look, just put the car in park or neutral and tap the gas. Don't floor it and hold it there—that's how you blow something up. A quick, smooth jab is all you need to hear the engine roar. It's fine to do once the temperature gauge is out of the cold zone, but if the engine is still cold, you're just causing unnecessary wear. Be mindful of your neighbors, too; nobody wants to hear that at 6 a.m.

[DiNoah]

As someone who's rebuilt a few engines, I'm cautious. The key is a fully warmed-up engine. Check that the oil temperature is at least 160°F. Then, with the transmission in neutral and the parking brake set, I apply the throttle progressively. I listen for any unusual sounds—knocking, pinging—that could indicate a problem. It's a diagnostic tool as much as anything. I never hold it at a high RPM for more than a second or two. Mechanical sympathy goes a long way.