As hydrogen releases more energy than petrol, H engine is more powerful than petrol .
A petrol engine revs higher, which allows it to burn more fuel and output more power.
It will depend upon the conditions. Under normal operating conditions a diesel engine is more efficient than a petrol engine.
for same power diesel engine produces more torque @ less rpm whereas petrol engine produces less torque @more rpm this difference is due to different combustion processes of diesel and petrol
Yes
It doesn't. The engine uses petrol any time it is running, but not more when braking.
Overall it is about 20%
No, diesel engines cost more to build than petrol engines. They are built much heavier.
Yes, extremely! The higher the number the more powerful the engine is.
Diesel is a more combustible fuel than petrol, therefore less fuel is required to generate the same power as petrol. This also means that spark plugs aren't required, like in a petrol engine, since the diesel will ignite off engine compression alone. This also makes the engine arguably more reliable since there are less parts, and less things to go wrong.
Because of higher compression ratio.
Diesel engines are more efficient and do use less fuel, but they do not cost less than a petrol engine, they cost more. Diesel fuel also costs more. A diesel engine will however last longer.
Crate engines can provide power to any type of car. A crate engine is very powerful. A crate engine is much more powerful than a regular engine as it produces much more horsepower.