Crosman will recommend pellgun oil. Umarex Recommend silicone oil. But some people will just use transmission fluid. I think you would be fine with anyone of the three. And although there might be a few people on here that will say no, there will be quite a few people that will say it will be fine.There was a big discussion on the GTA Forum about that. And some people believe that pellgun oil Is just a transmission fluid. Somebody even called Crosman and they couldn’t give them a definite answer.Although my Umarex Guns say use silicone oil ,I still use Pellgun oil. Just Google it yourself and you make the decision on what to use on CO2 cartridges. I understand you don’t want to mess your gun up but I’m telling you what a lot of people use and it is anyone of the three. But I was always told by many people that if you use 30 weight oil, make sure it is non-detergent. I don’t like using it myself.