i have a very near stock R32 GTS4 rb20det, its got i nismo air filter in standard box and a Split dump pipe, but in saying that i have 157kw at the wheels and still running stock 8psi
also i did a freak run, i got 407km from my last tank and filled 60L, mostly highway with full car!!
weird if you ask me cause i thrashed it with an extra 250kg extra