For some reason my temperature guage 8 degrees too high. 
don’t know whats wrong. 

Persistently or on initial startup and before driving off? 

 

What are are you comparing the temp with? 

Hi. 
all the time and i can tell the difference but also jump in my daf HGV for work and thats hiw i kniw

The temperatures in the car will always be slightly off with the true air temperature because they are shielded from the elements somewhat and a happy medium needs to be found so that they are far enough away from the engine and drivetrain to not have the heat from those affecting the reading and also not be exposed so that the colder air hitting the car whilst it's travelling doesn't give a low (colder) reading.  Even whilst on the move there will be friction/heat radiation from the road and tyres so that will also skew the reading.  It's a flawed system due to the amount of variables and external influences on the reading but it's just there to give you a rough indicator.

 

If the car is still under warranty then take it into the dealership for investigation if it's blatantly and consistently wrong. 

 

 

Penguin is quite correct of course, but to add some context all of my Superbs, including the current Mk3 have been within a degree or so of the real temperature, so if yours is reading 8 degrees different then there is definitely an issue. 

Thanks for the replies guys the temp on my HGV is always in the ballpark and as I said it was ok till a few weeks ago 

I will have a look for the sensor and maybe  change it don't think it will be that dear.