Does your fuel gauge read at or below F when filled all the way up? Do you still have a ton of fuel at E? If so, both your fuel gauge and temp gauge are reading low. There's a voltage limiter in the circuit for those gauges, and if it loses it's ground (a screw on the back of the panel PC board), the gauges see full batt. voltage and permanently warp the bimetals inside that move the needle, causing a low reading on both. Taking the gauges apart to "unwarp" the bimetals with brute force causes the age brittle needles to fall into many pieces. Any glue you use to put the needles back together ruins the weight balance of the needles on the counterpoise spring. You buy a 5gal can of fuel for "lack of fuel gauge" events. A calibrated stick comes in handy, to poke down the filler hose and check the fuel level. Steam from under the hood is a reliable indicator of engine overheat. Who cares if the engine is cold?