progression of turbo technology

In the past when someone mentioned that their car was turbo charged the first thing that sprang to mind was the car is costly to maintain and you would need to change the engine oil every 5,000km, and maybe do a turbo rebuild every 30,000km! You would also think that the car will be a wild beast to drive as there would be a lot of turbo lag below 3,000rpm and the car will suddenly surge forward when the turbo started to boost. It was like driving a car with an "On / OFF" switch!

All of this is in the past. The new age turbos coupled with better exhaust flow design and engine combustion have significantly reduced the dreaded turbo lag and the engines are better designed to handle the extra stress from high power and torque.
Turbos are now much more reliable and the cars using turbos are not required to change engine oil every 5,000km. Turbo technology has progressed by leaps and bounds compared to 30 years ago when the turbo craze was going on. Now with the European car makers taking the lead in engine down sizing turbo engines are found in nearly all European car manufacturers. The efficiency of the turbo has improved so much that super charging has now taken a back seat. Companies like Mercedes Benz which previously was a strong proponent for super charging has changed to turbo charging for their small engines. Turbos are more efficient than super chargers since they only use the exhaust gas to drive the turbines rather than using engine power to drive the super charger pulley.

The main changes to the turbos now compared to 30 years ago are:
- roller bearing with inertia
- Variable geometry turbo system which allows the blade to change the angle of attack to reduce turbo lag, faster spool up and improve boost across a wider range of  the RPM
- ceramic turbos (for better heat management)
- triple turbo technology (BMW pioneered this with the new M50d)
- multi stage boost pressure control (for cars with additional boost for overtaking)

Currently you can find turbos fitted in cars with small engines (660cc) to large engines (5,000cc or more). The application range is much wider now and turbo charging is now more affordable than before.