This is direct from Mazda
Garrett T25 Turbocharger System
Garrett is the largest manufacturer of turbochargers in the world, providing engine boosting systems that save fuel and reduce emissions while providing an increase to engine performance. Garrett's turbocharging business has sustained its reputation for innovating turbocharger technologies generation after generation. From its long list of industry firsts to its leading-edge ball bearing turbos for racecars, Garrett develops and manufactures the same cutting-edge boosting expertise that goes into all Garrett products.
Most of the world ' s top engine and car manufacturers, including Mazda, employ Garrett turbochargers to boost their engines, and with 27,000 turbos produced every day, Garrett is a name to trust. The T25R ball bearing turbocharger featured on the Mazda Proteg uses some of the same technologies as seen in the Garrett Motorsports product line. Interesting facts about the T25R ball bearing turbo include:
The ball bearing turbos have less rotating friction than traditional journal bearing turbos. This increases turbine efficiency which allows the turbo to come up on boost earlier and more predictably. This translates into enhanced throttle response (crisper).
The T25R turbo's ball bearing cartridge is much stronger and more durable than an ordinary journal bearing turbo. As long as the driver maintains his Proteg by changing his engine oil at regular intervals, the turbo will likely outlast the life of the engine.
The T25R has a high temp compressor wheel and a turbine housing cast out of an innovative high temp material (Ductile Ni-Resist) to further improve the durability of the turbo. The end result is that the turbine housing will be nearly impervious to warpage and cracking.
The water cooling lines that run to the turbo allow the unit to resist the traditional 'coking' of oil during hot engine shut-downs. When the engine is shut down and the turbo is still very hot, a thermal syphon is created in the turbo water jacket. This has the effect of thermally pumping water through the turbo to keep it cool.
http://www2.msprotege.com/forum/showthread.php?t=47088&page=2&pp=15&highlight=t25r
Here's the thread I originally posted this in. Post #18 which is on the second page.
Hope this helps!
<!-- / message --><!-- sig -->