smiths oil temp gauge

Recently installed a smiths oil temp gauge and sender in the 64 bus and temp on gauge showing 130 - 140 degrees under normal driving conditions when actual temp measured with temp gun 70 - 80 degs.
Rang smiths and they told me their gauges are designed to work with 10volt supply only, therefore my system being 12v (13.6v when running) is the reason for temp showing high.
Anyone heard or know of this? Cannot understand as why would you make an automotive gauge to work on 10v when all cars use 12v system?

What, really ??? That's crazy... what did the instructions/specs say ???

Never heard of anything like that... requiring a MINIMUM of 10V maybe, as in 10-14V, but not ONLY 10V.

Maybe try talking to someone else at Smith's, cos it sounds like BS to me....

Installed gauge a couple of months before engine installed and running and threw away instructions/specs at that time, but would have noticed if it said about 10V only. Gonna call again and see if I get the same answer, but I agree it sounds like a lot of BS.

Actually, you know it may not be BS... take a look see at these contraptions

http://home.mindspring.com/~purlawson/files/SmithsVoltageStabilizer.pdf

& http://www.freewebs.com/classicstabilizers/CCVS1_Installation_Instructions.pdf

Anyone else think they look like the "ballast" on a 12V Beetle fuel gauge ???