gauges are just a base to judge off of. everyones will read a little different. they might be a little off from someone else's, but they will most likely read consistently with themselves( meaning daily values will be the same). you can't base the life of your engine off your gauges. they do nothing more than tell you something isn't right( ie.one day your oil pressure reads higher than normal) a bad gauge can still tell you something isn't right by reading different. i do think the meagan's will be fine though. they will most likely do exactly what they are intended to do. what does a defi do that an autometer doesn't? nothing.