more efficient. After the 7 years at 19 psi with the stock turbos I went to the TD05-16G turbos. And for the last 3 years I have been running 25 PSi with the TD05's :). Same stock motor for 10 years now running 19 to 25 psi. Also for the last 2 years I have been running a 60 shot of N20 on top of the boost. You just need octane and good tuning to make it safe as long as they can breath.