I find this thread very interesting.

The general thought with Landcruisers is that the factory gauges are very sketchy. Not assuming that MB factory gauges are crap also.

I installed in my diesel landcruiser a coolant temp, oil pressure, and pyro.
The main reason is I wanted mechanical gauges that gave much more specific/accurate readings. Both the temp and oil pressure factory gauges don't in my opinion give a specific enough reading. For example the factory oil pressure reading would show as low, but with my aftermarket gauge I know that it is at an acceptable level for idle. Same with the temp, I have seen a 40 degree spike on the mechicnal gauge with only a slight bump from the factory gauge.
As far as a pyro, the diesel in my LC is only a 90 hp N/A engine and the egt's can spike pretty high if it startes lugging or during long hill climbs.

I plan on all three of these plus a boost gtauge for the 300SD.

Tim

Sorry if the post seems rambling, was up early with the little one and I have had at least one two many cups of coffee