anybody have any idea what a 3rd gen's fuel usage would be when idling for hours? think maybe 1 gallon her hour? Im curious cause I need a rough estimate.

thanks,
tom

 

Don't know about a 3 gen but mine idled for about 8 hours one day for heat and the needle moved VERY slightly.

 

I believe the average is about 3 liters an hour (depending on air temp, water temp, if you have an engine brake, etc). There are 3.78 liters per US gallon.

 

thanks guys

 

I was always told a good rule of thumb was a gallon per hour.

 

If you are going to idle for any extended period of time make sure you do so in neutral and idle the engine up to 1100 rpm.

 

Yeah, I have read that the Cummins should be idled up beyond 1000 rpm if left to idle for extended periods of time.
Fuel usage should be about 1 gallon per hour.
Don't go by the fuel gauge though. Fill it up, run it for a few hours and top it off to get an exact usage.