Ron,
The float is accurate when you realize it measures inches of fuel not gallons. Since there are fewer gallons in the bottom 25% of the tank than the top 25% it just means the needle on the gauge is going to move faster so it should be checked more often although I don't think too many people operate in that bottom quarter. You should probably consider the bottom quarter to be your reserve or time to find a fuel dock.
Ideally if you could start with a dry tank you could measure how many gallons it takes to reach the 1/4 mark then the 1/2 mark etc. The problem is nobody wants to run their tank dry so that most important bottom 1/4 can be accurately measured, it's also not a good idea with a diesel motor. So unless you prefer to do burn rate calculations probably best to keep a sharp eye on the gauge should you find yourself at the bottom side of the gauge.
The float is accurate when you realize it measures inches of fuel not gallons. Since there are fewer gallons in the bottom 25% of the tank than the top 25% it just means the needle on the gauge is going to move faster so it should be checked more often although I don't think too many people operate in that bottom quarter. You should probably consider the bottom quarter to be your reserve or time to find a fuel dock.
Ideally if you could start with a dry tank you could measure how many gallons it takes to reach the 1/4 mark then the 1/2 mark etc. The problem is nobody wants to run their tank dry so that most important bottom 1/4 can be accurately measured, it's also not a good idea with a diesel motor. So unless you prefer to do burn rate calculations probably best to keep a sharp eye on the gauge should you find yourself at the bottom side of the gauge.