I checked out the tubo specs on the garrett website
www.egarrett.com.au.
"GT30-GT45 Garrett turbochargers are designed for commercial <b>diesel</b> engine applications rated from 200 hp to 600 hp. They are typically installed in engines used in on-highway and off-highway vehicles, construction equipment, farming, marine and stationary applications. "
Aparently in a diesel engine the turbo is rated to about 275kw.
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Not sure about petrol tho.