Do you have any examples of a RavenTai modified OEM 80 series temp gauge failing? I haven't heard or read of a failure. When the OEM gauge is returned to a true reading temp gauge, I believe it's as reliable and accurate as any Toyota temp gauge. Please tell me of ANY automotive part you can rely on 100%. It wouldn't hurt to have a redundant temp gauge, but that's splitting hairs and quite anal, unless there's evidence of inaccuracy. The only reasonable area of concern IMHO, is IF the person that modified the gauge was incompetant or botched it up. It is a delicate electronic part, that should have experienced hands doing the mod. I modified my gauge & was an electronics tech, in one form or another, my whole career and rely solely on my modified gauge for my 1FZ's temp status. I trust it for what it does and have no reason not to.