You aren't burning 500 calories in 20 minutes on a treadmill

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Recip engines of various sizes are limited also by the maximum acceleration of their parts. More precisely, by the maximum strain energy per unit volume in critical parts, like the rod bearings. McMahon's book On Size And Life has a very good description of this and an analysis of engines ranging from tiny model airplane motors running at 25000 rpm, to gigantic industrial motors run ing at a few tens of rpm.

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I really need to find the right time to say borborygmus in a conversation.

Yes! When a girl reaches around and grabs you in a friendly way, it can happen fast.

I know still do not as much as diesel engine

Haaa...so did I!

As far as I know it's only the volume of the food that makes you feel full.
That's the reason some people say you should drink a glass of water before you start to eat.

Gas turbines produce soot, just like any other engine.

>its called borborygmus

Are you sure you're not just summoning a demon?

me too, French fries taste better with some kinds of meat, during mashed potatoes taste better with Fishsticks and other stuff.

Gas turbines can do a continuous burn to build pressure, limited only to the total flow of fuel and air.

Diesels are pulsed ignition, and are limited to how much fuel+air can fit in the cylinder without igniting early.

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> I'm already in a huge calorie deficit

Then you already burn more than you consume. "Burn more than you consume" is just another way of saying "have a calorie deficit".

The most important difference is reciprocating mass. Piston engines have reciprocating masses - things that move one way, then turn around and move the opposite way, all along the same axis. In a turbine engine, it just goes round and round, so nothing has to handle all the force of repeatedly reversing direction. It's also called an "engine", but it works entirely differently, and so very different physical limitations apply.

You're getting other answers that are sort of fixating on the "diesel" part of your question and why diesel engines rev a little lower than gasoline engines, but that's not the critical difference between piston engines and turbine engines - it's all about the reciprocation.

I have a very rudimentary understanding of engines and this laid out very clearly why engines revolve at the rates they do. Thank you.

As a side note, do you know why that one diesel le mans car from Audi could still rev as high as it does (8k iirc)? Is it kind of the same reason as why high performance gas engine also rev much higher than regular gas engines.

Definitely seems to be a regional thing