they both have pros and cons
I may have ONLY 2 gauges on the side post but they actually tell me things even thinking of adding in another gauge (coolant temp ) due to the simple fact the original coolant temp gauge does not move much.... so an external gauge will give more accurate readings
using gauges the driver becomes more aware because they are installed
full time of how the engine reacts to curtain loads and driving habits... basically we become more custom and diagnosing a issue becomes sooner rather than later
on the flip side
I had combustion washer issues this was allowing in exhaust gasses to my fuel system or fuel running back ( hard starting) when I installed my fuel pressure gauge I have drilled into the FPR tapped a thread (
this is a permanent install) the gauge has never been used for oil on my engine (just a gauge that I had in my toolbox ) ...... I noticed a fluctuation in pressure nonocom wont detect the same goes to a blocked FPR or dyeing fuel pump
over time I have become custom to how much boost RPM and fuel pressure this engine needs... I welly this engine allot as well as spray in LPG for extra power but my coolant gauge does not rise ..this is why I would like another gauge installed I have a murphy gage here sitting at home just need time to install
in the mean time my fuel pressure gauge has helped me fix 2 issues first issue has been covered... 2nd issue I had bent the fuel sender float arm removing my fuel pump to clean fuel tank and gauze pick up .... this gave fuel false readings I actually ran out of fuel when my fuel gage on the dash said I still had 1/8 tank ..... no fuel means no pressure
maybe the same issue brian47 has ie fool gauge comment but to lazy to fix or hasn't got the brains to how to reset the float arm height
I have set mine so when the fuel light comes on I still have 10 litres of fuel inside the tank