Every individual gauge can be different. That's why VW and almost all others leave off the numbers. Each individual gauge along with it's connected sender needs to be calibrated and adjusted. Good quality aviation guages are very expensive for this reason.
I put the sender in a can of tap water and bring it to a boil. 212F at sea level. This gives me a fairly true reference point to mark on the gauge. That's about as accurate as you can get without a lot more hassle.
Just trusting the gauge without verifying can lead you astray.
Every individual gauge can be different. That's why VW and almost all others leave off the numbers. Each individual gauge along with it's connected sender needs to be calibrated and adjusted. Good quality aviation guages are very expensive for this reason.
I put the sender in a can of tap water and bring it to a boil. 212F at sea level. This gives me a fairly true reference point to mark on the gauge. That's about as accurate as you can get without a lot more hassle.
Just trusting the gauge without verifying can lead you astray.
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Best thing to rely on is change from the 'normal' from perlonged observations. Not much help on a newly aquired vehicle; but then previous experience on a similar vehicle allows me to lift the bonnet [hood] and detect excess heat through smell/ feel/ :shock: hear :shock: [engine creaking as it cools]