Hi guys just joined just got my 350Z and love her, having looked into LPG one thing is clear you have to way up the fuel savings against the fact that lpg does not have the cooling and soothing ability as fuel does. This means depending on how you use it and the nature of the vehicle depends on how quickly the valves and valve seats errode. Its not a case of if but when all cars are diferent and the lpg use can change depending on user. An oil dropper can be and should be used this can exstend the engine life, switching between fuel and lpg during long trecks also can help. The problem with most oil droppers is they are not load related and they are usally a single point entry so uneven Atomisation. I did look into with a mate of mine at collage doing an engineering degree a design to build a sequential oil droper runing off a map sensor so it could increase as the load of the car increases. we were also going to look at aquamist. If i had a car running lpg i would put an EGT sensor in the leaner exaust run, this would tell you the heat difference between lpg and fuel so confirming the the effectiveness of adding soothing mods you have done. The use of uprated valve and seats also only delay the process to a degree. hope this is of help
