 |
| Jason Fenske, Engineering Explained |
That being said, why the difference in torque?
The answer to this question can be found at a YouTube channel called Engineering Explained. The video is aptly titled Why Diesel Engines Make More Torque Than Gasoline Engines. The host for this presentation is Jason Fenske.
Even though a cursory look at the two kinds of engines makes them appear similar, Fenske points out several subtle differences that appear small but have big consequences. They are as follows.
1. Compression ratio.
2. Speed of combustion.
3. Bore size vs. length of stroke.
4. Use of turbochargers.
5. Energy density of diesel fuel.
Gasoline is highly combustible, hence the pistons in a gasoline engine do not fully compress. It's the spark that does ignition. Diesel pistons are pushed further up within the cylinder because diesel fuel is ignited by the heat of compression.
The article includes a link to a 2014 blog post titled Throwback Thursday: What Does Torque in a Car Do?
For each segment, Fenske explains with useful imagery and technical diagrams. If you aren’t a car nut, torque is basically force multiplied by distance - and it is what causes your car to accelerate. For car enthusiast beginners this blog post gives a great introduction to torque, how to measure it and what it can do in your car.
What's especially interesting is how a basic presentation like this has had 1.5 million pageviews. It's quite apparent that this is a topic more than just a few people have wondered about.
Do you have diesel news or good diesel story?
Tell us about it. Send it to our Blue Flame director Karl Dedolph III @
The reason is a much higher compression ratio. This is the ratio of the maximum and minimum volume in the cylinder of an engine. It’s made larger in a diesel engine due to a longer stroke, meaning the piston is moving up and down a larger internal volume of cylinder. Diesel engines never rev as high as petrol engines due to the fact that the piston has to travel further for its full rotation, while a petrol engine uses its shorter stroke to move the piston in quicker bursts, meaning the engine speed can be faster.
ReplyDelete