The biggest problem with rotary engines was fuel efficiency. Possibly also durability of the seals? It's nice not to have reciprocating movement of pistons, but you simply cannot get the high compression ratios with rotaries, nor are the combustion chambers ideally shaped for thermal efficiency. In the Carnot cycle, where you have to maximize the delta temperature between combustion and exhaust, compression ratio is key for high fuel efficiency.

The combustion problems also result in increased emissions, compared with piston engines. Mostly unburned hydrocarbons, CO2, and CO.

Thinking back, the rotary engines got all their press hype before the two oil embargoes (1973 and 1977). These days, oil embargo or not, they would still be avoided, because of their higher CO2 emissions than piston engines. As we know, CO2 emissions were not an issue back in the 1970s, but they sure are today.

Take a look at this:

https://www.youtube.com/watch?v=v3uGJGzUYCI

In short, the advantage of rotary engines is that you can get very high revs, which means high power output from a small package. The disadvantages are poor fuel economy, relatively high emissions, and they did have some seal durability issues too. Possibly, those durability problems were improved.

The biggest problem with rotary engines was fuel efficiency. Possibly also durability of the seals? It's nice not to have reciprocating movement of pistons, but you simply cannot get the high compression ratios with rotaries, nor are the combustion chambers ideally shaped for thermal efficiency. In the Carnot cycle, where you have to maximize the delta temperature between combustion and exhaust, compression ratio is key for high fuel efficiency.

The combustion problems also result in increased emissions, compared with piston engines. Mostly unburned hydrocarbons, CO2, and CO.

Thinking back, the rotary engines got all their press hype before the two oil embargoes (1973 and 1977). These days, oil embargo or not, they would still be avoided, because of their higher CO2 emissions than piston engines. As we know, CO2 emissions were not an issue back in the 1970s, but they sure are today.

Take a look at this:

https://www.youtube.com/watch?v=v3uGJGzUYCI

In short, the advantage of rotary engines is that you can get very high revs, which means high power output from a small package. The disadvantages are poor fuel economy, relatively high emissions, and they did have some seal durability issues too. Possibly, those durability problems were improved.

One of the problems with the rotary engine is that oil must be injected into the chamber every cycle in order to lubricate the seals, engine oil does not burn cleanly and it also means the engine oil must be periodically topped up.

I think this problem is actually quite easy to solve, by having a separate tank for the oil to be injected into the chamber and using a cleaner burning lubricating oil in this tank. E.g I used to own an RX8 and I used Motul 800 Ester synthetic 2 stroke oil which burns cleanly.

The rotary engine can be made more thermally efficient if it is designed to run at a fixed speed - as such in conjunction with its relatively compact size and low weight it may yet find some use as a range extender for electric vehicles.

there are two reasons of management,

- Energy MP which is after dead life of many parts especially important parts, we are going to proceed maintenance for rest of parts which will burn money and extra energy.

- business , this is more in scope, every product will need update, promotion and up grade following of sales next product in good time.