CHECK OUT WHY TURBOCHARGER IS MOSTLY USED WITH DIESEL ENGINES RATHER THAN PETROL ENGINE

Why is a turbocharger mostly used in diesel engines when compared to petrol engines?

There are really no limits to how much turbocharger boost you can put on a diesel engine, other than the strength of the engine components. Most diesel engines are very robust compared to gasoline engines, so you can use a lot of boost. On the other hand, gasoline engines are limited by pre-ignition (“knocking”) which can damage the engine, so you can't use as much boost, and you have to take special measures to avoid engine damage.

Gasoline engines use spark ignition, but if the cylinder pressure is too high during compression, the air-fuel mixture will ignite too soon, during the compression phase before the spark plug fires, and the shock can damage the engine. There are various ways to avoid this, such as using knock sensors which back off the boost when they detect knocking, lowering the compression ratio of the engine (which reduces fuel economy), or using higher octane gasoline (which costs more money). There are limits to the octane rating of automobile gasoline, and you can't use aviation gasoline in cars because it contains lead. (In WWII they put so much lead in the gasoline for supercharged fighter aircraft that the planes would get lead streaks down the sides from the engine exhausts).

Diesel engines use compression ignition with much higher compression ratios, which means they get better fuel economy than gasoline engines, and they control ignition timing by injecting the fuel directly into the cylinders when they want it to ignite, which means there is no possibility of pre-ignition. This means that the boost they can handle is only limited by the strength of engine components. The octane rating of the fuel is irrelevant, so they can use the same fuel, and increasing the boost level only increases the fuel economy.

Trucking companies tend to buy trucks with very robust diesel engines and boost them as high as they can, which results in both more power and better fuel economy. This costs more money in initial purchase cost, but results in savings in fuel costs over the long term.

Private individuals are more interested in getting a good looking and powerful car which doesn't cost very much, so they buy gasoline cars, in which there are limits to the power boost turbocharging can give them, and it doesn't give them much advantage in fuel economy.