Non rallye fuel gauge accurate??

There is also a voltage limiter for the gauges.
As for accuracy.. These are not gauges. They are range indicators at best. You should expect a gauge to show full when the tank is full and empty when the tank is empty. If it shows full after you know a few gallons have been used, thats normal. If it shows empty and less than tanks capasity is needed to fill it, thats normal also. Bottom line, everything between the end limits of the range is wide open.
When do you know for sure a range indicator needs service ? When it shows you have better than empty yet run out of gas.
Water temp and oil pressure gauges should be of more concern since their false report can result in serious engine damage.
You can have all of them inspected and qualified for continued use, along with OEM accuracy for as little as 15 USD each. Hope this helps