Is Revving Your Car Bad? [Do It Carefully!]

In this guide, we will discuss “is revving your car bad?” Car enthusiasts always love to rev up their cars above the redline on the dashboard when they find themselves in the “shiftronic mode” to enjoy the deep exhaust notes “VROOM VROOM” of their engine. It might sound cool but revving a car above its limits can be detrimental to your engine in the long run as the mechanical compoennts of engine will be under extreme load and stress when you rev your car.

Revving your car can be bad as it will damage the engine components such as crankshaft bearings and camshaft. Revving your car for longer periods may even result in the engine overheating. If the engine temperature goes beyond normal limits, it will affect the engine’s performance in terms of power output. Moreover, if the engine oil is old, or it is misfiring or running lean, it will make exacerbate the pre-existing issue. In addition, revving your car can result in decreased fuel economy of your engine in the long run. Moreover, if you rev up your car, the engine noise might disturb people around you. 

In some cases, our engine has to be revved higher. For instance when you’re towing or when you drive above 150kph in 5th gear, the engine RPMs go higher. So, you should always make sure to keep the oil and filter changed at regular intervals as they play a key role in engine’s performance. 

Revving A Car Engine: What Does It Mean

So, what does revving a car engine mean? Revving your car means that you are pushing the accelerator pedal all the way and trying to get the maximum power and speed from your engine, when the car is in park or neutral.

The term ‘Rev’ is a short form of ‘Revolution’. The crankshaft revolution increases as we push the accelerator/gas pedal. As we push the gas pedal, more air is allowed to enter the engine. When the ECU detects more air in the engine, it will send signals to the fuel injector to inject more fuel. As a result, more energy and heat will be produced when the air/fuel mixture will burn. 

When the engine is revved, the RPM goes up. This means the engine is producing more power. But revving a car engine for longer periods can cause wear and tear on internal components. As a result, your engine may start making loud noises.

Car idling noise is the sound of your engine. It may start at low speeds and gradually get louder as you rev up the engine. Revving up the car also puts engine fluids, such as transmission oil, motor oil, and coolant under high pressure. 

Read my guide on how far can you drive a car on minimum engine oil for more details.

Why Does Engine Make Loud Noises When You Rev Your Car?

The loud noise from the engine when you rev your car is the sound of exhaust gases and the sound produced by mechanical components when they rotate at high speed.

When you rev up the engine, the combustion is taking place at a rapid rate. As a result, the speed of exhaust gases also increases. When exhaust gases travel through the exhaust system at a very high speed, they emit loud impulses of sound.

In addition to exhaust gases sound, the mechanical components of the engine, such as bearings also emit a loud sound when you rev your car, especially if the engine is old and its parts are worn out.

“The more often you rev your car, the faster the piston rings and cylinder sleeves will wear down.”

What Happens When You Rev Your Car Before Engine Warm Up?

If you have just started your car and you are revving it without waiting for it to warm up, it can cause serious damage to your engine.

When you’re just starting the engine, the motor oil takes time to flow from the crankcase to the engine oil galleries and achieve a certain level of viscosity. As engine temperature increases, the viscosity of motor oil becomes suitable to carry the crankshaft load and bear the stress exerted on the oil films in cylinder walls. 

So, revving the engine before it gets warmed up could cause excessive wear on the engine’s components due to greater friction between connecting rod and crankshaft, and between the piston and cylinder wall. In the long run, it could even cause the engine to be seized up.

Does Revving The Car Burn Gas?

Revving the car burns gas and affects its MPG as you are just burning the fuel at idle load. When you rev the engine of a car, the engine is forced to work harder and use more fuel than usual. This is because revving the engine is a way of making the engine turn faster by fully pressing the accelerator pedal.

This effect isn’t just limited to cars but applies to all engines. Revving the engine will indeed burn more gas than normal driving. But, it is the same with revving a motorcycle.

If you rev your car too much, you should check the oil levels and other fluids regularly because the engine gets more work from them and can affect the quality of these fluids.

Some people also want to know about the fuel consumption of their cars when they are engine is running at the same RPM but they are driving at different gear positions. Let’s say you are driving the car at 3000 RPMs in 3rd gear and then drive your car at 3000 RPMs in 5th gear.

Your engine also has an accelerator pedal sensor that tells the ECU about the exact position of your accelerator pedal so that the ECU calculates the necessary air intake and fuel injection. The more the accelerator pedal is pressed, the more fuel will be injected and burnt to achieve higher engine RPM.

When your car is in low gear i.e. 3rd gear, your car experiences more load than when your car is in 5th gear. This is because, in lower gears, the engine experiences more torque. The greater the torque, the greater will be the load. Also, note that there is a difference between engine RPMs and wheel speed. To learn more, you can read my guide on what does low gear mean in a car.

So, in lower gears, you often push the accelerator pedal to the floor, and your engine revs up and reaches higher RPMs quicker. In that case, the car is not moving much but higher RPMs will require more fuel consumption due to an increase in load.

On the other hand, when your car is in a higher gear (5th gear) and you rev it up, you don’t have to fully press the accelerator pedal. But your car will travel more distance in that case. So, your car will have a higher MPG i.e. your car will burn less fuel to cover one mile. Since you don’t have to fully press the accelerator pedal in high gears, the ECU will calculate that less fuel is needed for combustion due to a lesser load.

How Does Revving Your Car Cause Wear and Tear On The Engine?

Here is how revving your car causes wear and tear on the engine:

Overheating

Revving your car at idle for a long time can cause the engine to overheat. This is because the radiator will receive less air, thus it will cool the coolant less efficiently. When the engine is not moving enough, the radiator forces less air, due to which coolant is not cooled down to the desired temperature. As a result, revving might overheat the engine.

Piston Compression Ring Expansion

The piston has compression rings that allow the piston to smoothly slide against the engine cylinder and prevent oil from entering the engine cylinder. If you rev your car at high RPMs, it will heat the piston rings much faster. Piston rings show a sudden expansion in heating. So, if piston rings expand too much, there will be increased friction between cylinder liners and piston rings. It might also crack the piston and wear out the cylinder liner.

Connection Rod and Crankshaft Warping

A connection rod is a link that transfers the motion of the piston to the crankshaft. Revving your car at higher RPM for longer periods will excessively stretch or bend the connecting rod. This will exert unbalanced forces on the crankshaft, which can cause excessive vibrations in the engine and may also damage the crankshaft bearing.

Is Revving Your Car In Park or Neutral Bad?

Revving the car in park or neutral is not bad as long as it is lesser than the rev-limiter (redline), would be better if RPM is lesser than 3000 when you rev your car in park mode. While your car is in park mode, allow the engine a few seconds to warm up before you rev your car. In addition, revving your car in park for so long will burn excessive fuel.

Does Revving The Engine Warm It Up Faster?

No, you do not need to rev the engine to warm it up faster. The best way to warm up the engine faster is by driving your vehicle. It is a myth that revving the engine makes it warm up faster. The reason why most car owners rev the engine to warm up the vehicle is that they believe that it will make the engine run more smoothly. However, there is no scientific proof that revving the engine will make the car work better.

Today’s electronic modern engines take less than a minute to transfer oil to the oil galleries and build the necessary oil pressure so that all engine parts work efficiently.

In winter, oil takes some time to reach oil galleries. It’s true that by revving the engine and increasing its RPM, the oil pump will push the oil through engine oil galleries at a rapid rate. But, if you do it as soon as you start your engine, it will cause wear and tear on the vehicle.

Due to this reason, it is advisable to start driving your vehicle after 20 to 30 seconds of driving your engine to warm your engine faster compared to revving your car in park or neutral mode.

When you drive a vehicle, the engine is under load as it requires energy to turn the drive train and move the vehicle. Moreover, the ECU will adjust the air/fuel ratio in a better way when driving. So, always prefer driving the vehicle instead of revving your car to warm it up faster. It will also save your gas.

Why Do Cars Lose Power When They Hit The Red Zone In Revs?

The car loses power when the engine hits the red zone in revolutions because the engine control unit has a rev limiter that will shut off the throttle, retard the spark timing or cut off the fuel injection to prevent damage to the engine components, such as valves, rod bearings, and crankshaft. So, when the engine management system stops the fuel injection or limit the throttle, the car starts losing power.

Is Revving Your Car Illegal?

Revving your car at idling can cause noise and smoke pollution, making it illegal to rev your car for a longer time. As a result, you could be liable for serious action depending upon the severity of the pollution.

At idle, the engine temperature does not increase that much, due to which the catalytic converter does not perform efficiently as it needs a certain operating temperature to perform. So, if you rev your car for a prolonged period, it may cause your engine to emit a lot of harmful emissions, including carbon monoxide (CO), hydrocarbons (HC), nitrogen oxides (NOx) and particulate matter (PM).

New Jersey prohibits revving the engine for more than 3 minutes. Otherwise, you may be charged a fine of $250 to $1000.