I have used the Fuel Meter reading equipment on a number of boats. Then there have been far more that did not have the meters. My conclusions are that the meters are marginally accurate in absolute terms. But, very useful in a RELATIVE way. In other words, I have never seen the meters to read anywhere near the real consumption(this does not apply to the newer electronically controlled engines like the Cat's where the fuel consumption numbers are normally "right on".) but I found it handy to be able to see in real time the relative consequences of a change in rpm. On numerous trips I have had to use the paper tables from the engine manufacturer to estimate fuel consumption. I have found these tables to be very accurate. In case this is not clear, I have used these tables to estimate fuel consumption in order to make a passages of up to 3600 miles across the Pacific and the numbers were in fact very accurate. It will soothe your mind if you can measure fuel consumed day to day or over several days in order to be sure that the consumption is as estimated. In any event, where the fuel consumption meters really help is when you change rpm and would like to see the change in consumption reflected in the meter readings, and you need to know now, not in a day or two. Mike Capt. Mike Maurice Tualatin(Portland), Oregon