It's all about having the best tool for the job. If the job is knowing that your engine is
starting to overheat, you have several choices. The three that seem to be in discussion here are:
- A gauge
- A warning light
- A "limp home" mode
A gauge requires that you pay attention and notice that it is starting to move toward the yellow or red region. If the needle moves slowly, and you're not presently concerned about it, you may not check it often enough. And, yes, even if you are a car guy.
Historically, the problem with warning lights is that they only turn on after the problem is serious. That's not a problem with warning lights, it's a problem with their implementation. A warning light that turns yellow when the coolant (or oil) is hotter than normal, then turns red when it's actually starting to fry would actually be quite useful. The light turning on and staying on would do a much better job of grabbing your attention than a slow moving needle.
A "limp home" mode is a no-brainer. Basically, protect the expensive parts of the car from damage. Combine a "limp home" mode with a
good warning light, and the gauge becomes unnecessary.
Now, I don't honestly know if BMW's warning lights are what I would consider good, but if they are, I say dump the gauge.
But what if your job is knowing when it's okay to rev the engine? Look no further than the M solution of putting lights around the tach that indicate how high you can rev the engine. As the engine warms up, the lights sequentially turn off. As far as I'm concerned, this is far more intuitive and useful than a temp gauge.
Bottom line, if BMW deletes a gauge and replaces it with something as useful or more useful, I have no complaints. It seems like BMW has dumped the gauge but not really provided a good way to know when it's okay to push the car (I think the lights on the tach is exclusive to the genuine M models). They do provide a clock, but unless you remember what time you started the engine, that's only somewhat useful. Also, ambient temperature would presumably have some effect on warmup time.
As for the lack of a dip stick, I can see this being a problem for people who change their own oil. For just determining whether I might need to add a quart at some time in the near future, the in-dash bar graph is good enough for me.