Fuel burn on twin 300

[Aln2202]

when running motors at cruise Rpm and motors are in sync. Is it normal for the fuel burn to be different between motors and if so what is acceptable?

[Moonlighter]

There will always be some degree of variation. You didnt tell us if you are running counter rotating props or .......

Variations maybe due to several factors including

- propellor pitch variation - even brand new props of the same make and stated pitch can vary quite significantly. Its a good idea to have both props scanned by an expert prop shop and have them tuned and balanced so they are identical. Makes a real difference in many cases having this done.

- the fuel data coming from each engine can vary from “true” slightly, which is why there is the calibration feature available for the interfaces. If you are running twin engines each drawing fuel from their own tank, you can calibrate to make both engines more accurate and get them both closer to true. This should also close the gap between each engine. I have seen 5-10% variation from true on some engines purely due to this factor. While other engines read 100% perfect out of the box.

Have you done either or both of those things?

What variation are you seeing?

[Aln2202]

Yes they are counter rotating. At WOT I'm seeing 1.5 gallon per hour difference. At cruise speed .7 gallon per hour difference.

easc motor draws from its own tank so I will check the calibration on that also.

[Hoosmatroos]

As Moonlighter already said, difference in props is the most likely cause. Even the slightest difference in rake, pitch, cupping or diameter can cause this