I have a racepak iq3 with various warning lights setup for oil pressure, water/oil temp, voltage, afr and have gone back and forth on the right trigger conditions. The warning lights can serve a few different purposes, some which are at odds, like:
1) basic warning condition that something is outside a range (low oil pressure, low voltage without rpm filter - lights up even when engine isn't running)
2) warning that car isn't warmed up (oil/water temp too low)
3) warning that only comes on when bad stuff is happening (over temp, low oil pressure). Oil pressure warning would be filtered by low rpm. Temp would allow low temps.

I like the idea of the warning lights never coming on unless bad stuff (3) is happening so I can react to it faster, but having conditions for the car warming up (2) is also useful especially since I don't have a thermostat on the oil lines. One idea is to have "bad stuff" on the left side of the dash and general warnings on the right. Maybe I'm overthinking this and I should just stick to basic conditions that light up unless the car is ready to be driven hard. Thoughts?

 

If the car isn't warm, you should be attentive enough on the gauges to notice. I prefer to leave the warning lights to catastrophic conditions.

The IQ3 should be capable of doing all of these:

-Oil pressure (under 25psi AND over 2000rpm)
-Water pressure (under 10psi, but only after it first exceeds 10psi)
-Oil temp (over 300*F)
-Water temp (over 230*F)
-Lean (AFRs >13.0:1 AND TPS > 80% AND conditions met for >2 seconds)
-Fuel pressure (varies depending on setup, but for a boosted car I would want something based on MAP as well)

The IQ3 is awesome enough that it will allow you to do the more complex oil pressure/water pressure/lean warnings easily within the software.

 

I preffer the warning lights to come on when it is a shutdown condition. A driver can respond instantly. If the light is on, kill the power. Otherwise just flash messages on the dash if the IQ3 is capable for the minor warnings.