Should You Engine Brake In A Manual And Does It Damage The Engine?
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Should You Engine Brake In A Manual Car And Does It Damage The Engine?

In today’s mechanics article, I want to discuss whether it’s okay to brake in a car with a manual transmission. This question comes up a lot on our social media, so let’s put an end to the confusion here.

Unlike normal braking, where you use the mechanical brakes to slow the car down, you use the forces acting against the turning engine to instead by taking your foot off the accelerator while in gear and/or changing to a lower gear.

Will Engine Braking Damage My Clutch?

Will Engine Braking Damage My Clutch?
– Will Engine Braking Damage My Clutch?

A common misconception is that you’ll damage the clutch or accelerate clutch wear when doing this. This isn’t true. You may however cause the clutch to slip (and therefore wear) if you actively use the clutch to slow the vehicle. Lift the clutch while in gear without rev matching and you will always cause a varying degree of wear. Simply letting your foot off the accelerator pedal does not do this.

How Does Engine Braking Work?

How Does Engine Braking Work?
How Does Engine Braking Work?

When you stop accelerating, and engine will stop pulling in outside air due to the throttle valve being closed. This vacuum that’s created is what slows the engine. Some may say that the compression of the engine also plays a part as the piston compresses the chamber, and while this is true, its effect is negligible.

This loss of energy is transferred to the engine in the form of heat, which is then cooled by the dedicated cooling system.

What Are The Benefits To Engine Braking?

What Are The Benefits To Engine Braking?
What Are The Benefits To Engine Braking?

There are three main benefits to engine braking in a manual car, but there are also benefits to doing in automatics, too.

  1. In most modern cars, once you’ve taken your foot off of the accelerator pedal, they will shut off the fuel injectors to save fuel. This means your drive will be much more efficient in regards to fuel usage. This also means your engine won’t run hot, despite engine braking producing some heat.
  2. You don’t put wear on your brakes. If light braking can be taken care of by the engine, it means there is no contact between your brake pads and rotors, elongating the life of these perishables.
  3. If descending down a hill, then engine braking can stop you from overheating your mechanical brakes. Long periods of braking can lead to brake fade, possibly warped rotors and failing brakes.

Does Engine Braking Damage The Engine Or Clutch Then?

No. There are still many people who believe that this causes excessive wear on either the gearbox, clutch, or engine, but this is wrong. As long as you’re not riding the clutch, rev-matching if you change gear, and not over-revving the engine, you’re safe.

Written by Alex Harrington

Alex started racing at a young age so certainly knows his way around a car and a track. He can just about put a sentence together too, which helps.

He has a great interest in the latest models, but would throw all of his money at a rusty old French classic and a 300ZX.

Contact: [email protected]

Comments

  1. The Institute of Advanced Motorists actively discourage engine braking and say “brakes are cheaper to replace than a gearbox” a statement I have never agreed with.

    • Hi Ricardo. Rev-matchihng is simply making sure the engine speed matches the transmission speed when changing down a gear. Double clutching is similar but more to do with older cars which have older gearboxes. Rev-matching minimises damage to the clutch.

  2. As a former ASE certified Master Technician with a degree in Automotive Technology I can attest to the soundness of the claim that engine breaking will not accelerate clutch wear or transmission wear if you know how to drive a stick properly. I have never had a premature clutch failure and I have a bad habit of using the clutch to keep the vehicle stationary on a hill. Lots of people have misconceptions about manual transmissions, I have met several people who thought you had to shift 1-2-3-4-5-6 or you would damage the transmission. Others would just stay in a lower gear if they stopped accelerating, such as 0-45 they might make 3rd or 4th then just sit there in that gear until they either have to stop or accelerate to a higher speed. Other people think slow acceleration is better for mileage. Thanks for the article.

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