@princesirohi
To my understanding, compressed volume and internal combustion, if u agree is compression and combustion (in short)?, if so then they are obviously associated to a working of a 4stroke piston engine. Where, what u said are of course part of the Otto cycle sequence i.e. INTAKE > COMPRESSION > POWER > EXHAUST. (combustion in this case is power since only after combustion, the piston move the crank) since the whole idea to put forward this derivation in short is constant volume, is because there is a CC (cubic capacity) as described to a particular piston engine. But a gas turbine engine, Like the engines installed to a aircraft(jet engine) works on the principle of constant pressure, and if u still say no, then tell me the CC of a rolls royce trent 800 engine (Rolls-Royce Trent 800 - Wikipedia, the free encyclopedia).

All right guys, got the engine oil changed, and before changing and all suggestions right here.,
I took a little back step and just added 200ml of diesel in the engine, then idle runned it for about 2minutes and just kept hand on the engine to check if any heat building up abnormally but no signs of it.

Then after 2 minutes turned off the engine and opened the oil valve and observed engine oil black in color, but couldn't distinguish between a burn't out oil or a oil with any particles in it, (the oil had done over 2500km) and refueled with shell engine oil(mineral).

Did feel a change, not sure was it because of new engine oil or was that diesel effect but a slight improvement in pickup and performance with a noticeable difference in acceleration. drove over 200 km after that and no warnings from engine so far