Forestry mulcher fuel consumption question

I have a Kershaw 10-10 with a ~6.5 ' Fecon mulching head and non turbo 3208 Cat which I've been having fuel problems with so I mounted a calculated 50 gallon tank on top and plumbed it in. I ran through nearly 2 tanks of fuel in 3 hours today grinding down small thick ash and hackberry sapplings around larger trackhoe clear timber. Is my math right that I'm burning somewhere above 25 gallons per hour?? Not knowing what the original tank holds or what it was burning, I've been charging...

Forestry mulcher fuel consumption question

Forestry mulcher fuel consumption question