polyurethane
there nasty they make the neon vibrate a little bit when your stopped but the car starts up better and it goes better. when i'm going up a hill on the highway it usually looses power. and i have to down shift but now i just go right up. the engine sounds beafier at like 3500 to 4000 rpms it kicks in kinda and your hear it. i hear the engine over the exhaust. well the air intake. definetly aprove these.


