Is It Safe To Rev Out Your Engine?

If you’ve recently learned out to drive a manual transmission car you may be hesitant to rev out your engine to max RPMs, which is understandable.  You may be wondering if redlining or revving out an engine can cause damage?  First, you need to understand what over revving an engine means.

What Does Over Revving Mean?

Over Revving an engine means that you rev your engine past the intended rev range set by your engine manufacturer.  With automatic transmission cars usually, the transmission will prevent you from over revving your engine by upshifting automatically or by not allowing you to shift to a lower gear if it has the potential of over revving the engine.

However, with manual transmission cars there is a rev limiter but there usually isn’t anything preventing you from downshifting and accidentally over revving your engine.  That’s why it’s important to always take into account how fast your car is moving before deciding to downshift into a lower gear in a manual car.

Can Over Revving Your Engine Damage It?

Yes, there are countless stories online of people that have downshifted their car into a lower gear and accidentally blown up their engine.  An engine is designed to be operated at a certain RPM, exceeding that RPM can lead to catastrophic damage to your engine.  When an engine is over revved connecting rods can be thrown through the block of the engine, pistons can seize up, and flywheel/clutch damage can occur.  So it’s best to keep your engine RPMs at an acceptable level unless you want to risk blowing up your engine.

Does Revving Your Engine Damage It?

No vehicle manufacturer wants to make engines that will break down before 50,000 miles because they would risk being labeled a shoddy engine manufacturer.  That’s why engine and vehicle manufacturers will determine the rev limit of an engine after extensive testing of the engine to allow the engine to last as long as possible.

Rev limits of an engine will be determined based on a multitude of factors which include the parts used to build the engine, the engine configuration (overhead cam vs pushrod), the fuel injection method (direct vs port injection), and if the engine is designed to be used with forced induction.

With all that in mind revving your engine through the normal rev range will not hurt your engine as long as the engine has been properly warmed up and the engine cooling system is working properly.

Can You Increase Your Max RPM?

It is possible to increase the max RPMs of your engine through tuning, but should you do it?  Without supporting mods like changing out the camshafts, valves, and valve springs your engine may not be able to keep up with the increased RPM range.

After upgrading the internals of your engine you would next need to look at upgrading your drivetrain to be able to handle the increased RPMs coming from your engine.  You’d likely need to go with an upgraded clutch and input and output shafts on your transmission to be able to handle the increase in RPMs.

So just know that if you have your heart set on increasing your engine RPM on your car that you may have to also upgrade other supporting parts on your car unless you want to risk one of them failing.

What Happens If You Rev Your Car Too Much?

Can You Rev Your Engine Before It’s Warmed Up?

Revving out the engine in your car can be bad for the engine if it’s internal temperature is still low.  On a cold start, the internals of an engine hasn’t had a chance to properly warm up and the engine oil is still cold which means it won’t flow as well.

Once the engine has had a chance to warm up the oil will be able to flow better and lubricate the engine.  If you rev your engine before it’s been warmed up the oil may not be able to properly lubricate the engine which means more wear and tear on the internals.

In general, the more wear on the internals of an engine the shorter the life of that engine, but revving the engine in your car is fine as long as it’s been properly warmed up.

Is It Okay to Rev Your Engine In Park?

Yes, it’s ok to rev your engine while you are in park as long as the engine has been warmed up.  Revving your engine before it’s had time to properly warm up risks damaging the internals of the engine.  As your engine heats up the engine

Is It Bad To Hit the Rev Limiter?

Hitting the rev limiter can be bad for an engine because of the stresses that are put on the engine at high engine RPMs.  The rev limiter on an engine is put in place to keep you from damaging your engine.  If you hit the rev limiter once or twice you likely won’t do much harm to your engine but if you are regularly banging off the rev limiter before shifting you risk damaging your engine.

Is Redlining Your Car Bad For Your Engine?

Redlining your engine shouldn’t be something you get into the habit of doing but if you forget to shift once or twice it’s likely not that big of a deal.

The internal components of your engine are designed to operate under high RPM situations but if you max out your engine RPM you will be pushing the limits of your engine and the components within it.

Anytime you redline your engine you risk one of the internal parts (connecting rods, bearings) failing so keep that in mind.

Related Questions

Does Revving Your Engine Warm It Up Faster? While it is true that revving your engine can warm it up faster, I’d be hesitant to rev into the higher RPM ranges before your engine has had a chance to properly warm up.

Does Revving the Engine Charge the Battery Faster? No, the alternator which is responsible for charging your car’s battery has a voltage regulator built into it that regulates the voltage that is sent to the battery.

Without the voltage regulator in place the alternator would send too much voltage to the battery and overcharge it beyond levels that are safe.

So no revving your engine will not increase the voltage sent to the battery (as long as your alternator is working properly) or charge the battery any faster.

When Should You Not Rev Your Engine To High RPMs?

Does Revving the Engine Waste Gas? Yes, revving your engine can waste gas because it makes your engine work harder than it would at idle.  Your engine will be most efficient and use the least amount of gas while at idle.

So anytime you rev your engine to the high rev range you will be using more gas than you would if you let your engine idle. On the flip side, you don’t want to slowly accelerate from a stop, you want to accelerate in a reasonable manner to your desired speed and maintain it.

Slowly accelerating to your desired speed can use more gas because you will be constantly be using the accelerator and therefore using more gas.

Does Revving Your Engine Help When Jumping A Car? Revving your engine after jumping your car is a common myth that I once believed until I learned more about how alternators work.

Alternators have a voltage regulator that is designed to regulate the voltage that is sent to your car’s battery.  Without this voltage regulator, the alternator could send too much voltage for the battery to be able to handle and would overcharge the battery beyond safe levels.

Revving your engine will have no impact on the voltage regulator or the amount of voltage that is sent is sent to the car’s battery so revving your engine won’t help your battery charge any faster after you’ve had to jump it.

Is It Bad To Rev Your Engine In Neutral? Revving out your car in neutral is fine as long as you watch your engine temperatures.  If you are in neutral odds are you aren’t moving forward or aren’t moving forward that quickly.

The cooling system on your car needs air to pass through the radiator to effectively cool down the engine.  Without that air passing through the radiator your engine can overheat quickly which isn’t good news for the engine.