An ego-T or 510-T, completely un-modified, probably won't be great on 5v. The highest I've been able to go without out-
vaping them is 3.9v on a 510-T and 4.3 on an ego-T. YMMV. If they're modified in some way for faster wicking (or modified to use for dripping instead of
tanks) then they're fine for whatever you want to put them on