quote:Originally posted by Joules5:
Charlie,
Thanks, I'm in the process of swapping out the OEM 10qt oil pan for an Aviaid as the OEM is not baffled. It occured to me I have aftermarket gauges (oil Temp full scale 300F) so assuming the oil Temp sender is OEM it's full scale current would be at 280F, so I'll be reading about 7% high.
Maybe, or maybe not? I'm not 100% sure how these gauges work, but it would read 7% high if the internal resistance of your aftermarket gauge was the same as the stock gauge. But there is no reason why an aftermarket gauge couldn't have a figure of 100 ohm = 300F, or 50 ohm = 300F, or 200 ohm while the stock unit has a completely different value... The sending unit and gauge will be calibrated to work together but I don't know if there are industry standards for resistance to temp.
Rumor is that one of the reasons for inaccurate water temp gauges was due to a US sending unit and a Euro temp gauge, which implies that there may not be a standard for resistance to temperature conversion.
Not sure if I'm explaining myself well or not... but I think that only a matched sending unit and gauge will give a truly accurate reading, and only by measuring the resistance of the aftermarket sending unit and comparing it to the values of a stock unit will you know how they compare, and what % it may be off.