Now that i have my 4 Nitto 555s nitro-filled. And honestly I did go try it up a hill course. (you get the idea, its going downhill twisties, which is dangerous in weekends), anyways, for about 30 bucks to fill up all 4 tyres, i need to know when this 30 bucks worth it or not.. other then a total rip off..

This course is about 4 KM, so its 8KMs in total, the tyre set before is Falken ST 115 with regular air filled, of course both set of tyres are different but still a lot of thing can be seen after. First of all, I can really feel that at the second half of the course the tyre do grip better then the ST115, its not the from the orginial grip from tyre, the ST 115 will srceam like a bitch no matter how slow i go into apex. The ST115 will loose every grip it has, i have no idea where the car is heading during corners. Almost run into a wall as well. i chked the air pressure and it had raised sky high.. i pumped 30 psi in cold and after very hard driving it had raised to 38psi, unless I made a mistake. or the gauge is screwed. Thats the reading of it after about 6 km of a hard course running with ST 115. Now with Nitto 555 filled with Nitrogen, after the same course the pressure raise to 32 psi from a standard 30 psi!! i cant believe it at all from the readings. Its cold all after. by the feeling the tyre still have some grip after full 8km of course, It cant compare due to 2 different set of tyres. tho.

Thread life issue, i have went thru some reading of nitro-filled will increase thread life. I dont know, might be, as i know the pressure being constant. The tyres shape shoudnt change that much compare to air-filled tyres.

also the tyre are quieter then friends air-filled 555 @ 100km/h in HWY. (Same Type of car btw)

Bottom line, its just my first time exprience with nitro-filled tyres, the info might be wrong. its just for a reference if someone is interested.

Will go thru tracks and roads for more in-deep testing, of course im not a pro. but there are still something i could feel when driving, and inspect after driving i guess

for 30 bucks. so far i think its worth it.