Is It Bad To Engine Brake With A Manual Transmission?

There is a bit of a debate on this subject, and even after our buddy Jason from Engineering Explained breaks it down and explains things from a technical standpoint, there will still be those who say this is bad for your car. Of course, debates drive the world forward in many ways, so there’s really nothing wrong with that.

Jason steps away form his trusty whiteboard for this video, opting instead to take a ride in his car as he explains the logic and science behind his argument. He dives right into debunking one of the myths about engine braking, and that is that the braking effect comes from compression. That’s simply not true. As Jason explains, when you close the throttle, the engine pulls a vacuum, meaning it’s not getting a cylinder full of air when the intake valve opens, so there’s really not enough air in there to compress, at least not to the point that it would be enough to slow the car.

Braking this way actually has a couple of benefits too, which would almost certainly outweigh any negatives. Most notably, you’re saving your brakes. With the engine working to slow the car, there’s often plenty of opportunities to use that to scrub off speed instead of the brakes, which will save you money and time down the road.

It’s also efficient. If you’re driving on a road that’s sloped downward, you can simply roll out of the throttle and let the engine control the car’s speed while gravity does the actual work of keeping the car moving. It’s possible to cover a lot of ground like this without using any fuel. So, the verdict from Jason is that not only is engine braking okay, but is actually beneficial, so don’t be afraid to just roll out of the throttle and let the engine do a little work for your when it comes to slowing things down.