YES and I have a New sending unit that reads totally wrong. Another thing to consider since we are both in California is the gas you are using, when my friend and I used an octane booster, the cars actually ran hotter....food for thought
You might be on to something there. Went to Texas last year with my truck and the farther south I went, the worse the gas was. Overheating and poor gas mileage till I got back up north. Had to run premium till North Dakota just to keep it running.