Most of the motronic units, whether BMW or MB do this of keeping the temp essentially in the middle when its in their acceptable operating range.

My old 190E's used to show real time wild temperature shifts. Initially it worried me, but I got used to it. My BMW never, ever, flinched from the middle of the gauge. My w202's seem to flinch a little bit, but not anything significant. Anything out of range on the high side, and shut it down immediately, do not wait. Pull over at the first safe opportunity and shut it down. You do not want to warp a head or blow a head gasket due to runing the motor hot.

Anyone who is seriously concerned about real time engine operation data, needs water and oil temp, as well as oil pressure. But these arent exactly cars for the most part the general public drives hard.

Take care,

George

__________________
George Androulakis

Former Mb's:

1990 500sl R129 - 76k Original Miles - New project - Follow the saga http://90r129.blogspot.com/
1990 190E 2.6 148k mi (sold)
1989 420 SEL 246k mi (sold)
1995 C220 175k mi (sold)
1992 190e 2.6 74k original miles (sold)
2000 c230 Kompressor 122k miles (RIP)
1996 C220 149k mi (sold)
2000 C230 Kompressor Sport 127k (sold)

Current Cars:

2009 Mercedes c300 4matic
2006 Mercedes s430
2005 Jaguar XJR
2003 Cadillac Escalade