Tach lights - The Unofficial BMW M5 Messageboard (m5board.com)

gobuffs · 14th February 2007, 15:15

I am going to disagree with the conventional wisdom about the tach lights. I watched them closely today and I think the lights are tied to the oil temp and not the coolant temp. However, the final lights go out at around 140 (approx 60 Celsius). This morning it was around 32 degrees here. In the winter my car runs coolant temps around the first dot. When it got to normal operating coolant temp, the tach lights were still on above 5500. Once the oil temp got closer to the first dot (approx 165) all the tach lights went out (well all the ones that are supposed to go out).

Now the debate starts as to what oil temp is sufficient for redline. I have heard anywhere from 140 to 185.

NextCeo · 14th February 2007, 15:44

+1. I agree my tach lights behave the same way, as far as redline I just wait for the temp to reach the first dot in the oil temp gauge as well as water temp

kees · 14th February 2007, 16:21

Oil temperature is much more important than coolant temperature for how to treat the engine.

DRM · 14th February 2007, 17:42

Quote:

Originally Posted by gobuffs

I am going to disagree with the conventional wisdom about the tach lights. I watched them closely today and I think the lights are tied to the oil temp and not the coolant temp. However, the final lights go out at around 140 (approx 60 Celsius). This morning it was around 32 degrees here. In the winter my car runs coolant temps around the first dot. When it got to normal operating coolant temp, the tach lights were still on above 5500. Once the oil temp got closer to the first dot (approx 165) all the tach lights went out (well all the ones that are supposed to go out).

Now the debate starts as to what oil temp is sufficient for redline. I have heard anywhere from 140 to 185.

+1. Be assured those tach lights are tied to oil temp. Coolant temp is irrelevant to how the tach lights work.

Dan

Beamer_usa · 14th February 2007, 17:57

I don't follow the tach lights, they go out to soon. I use the oil temp. as a guide, once the oil temp is up to 180 (F) it's fun time!

SoCaLE39 · 14th February 2007, 18:04

Do all of your lights eventually go out? After driving around for 30min I still have what looks to be 2 lights lit by the 8k and 7.5k rpm.

DouglasABaker · 14th February 2007, 18:32

You will always have the last yellow and the red one lit - that is how you know where the actual redline is

the yellow is there to warn you you are approaching the redline and to use caution when revving that high.

d-

Beamer_usa · 14th February 2007, 18:32

Quote:

Originally Posted by SoCaLE39

Do all of your lights eventually go out? After driving around for 30min I still have what looks to be 2 lights lit by the 8k and 7.5k rpm.

The last two lights always stay "on".

NextCeo · 14th February 2007, 18:34

what would be cool is if there was software available that would indicated when to shift by having all of the lights light up at once. I think the SMG M3’s have this feature

foxyboym5 · 14th February 2007, 19:20

Quote:

Originally Posted by NextCeo

what would be cool is if there was software available that would indicated when to shift by having all of the lights light up at once. I think the SMG M3’s have this feature

not sure on the 'normal' SMG M3's, but the CSL definitely did IIRC

Nice feature!