Re: Dt 140 EFI fuel use on 20' Mako
Hard to tell what the fuel consumption is at trolling speeds but at wide open throttle it will be 14 gallons/hour give or take a tad. The general rule of thumb is 10% of rated HP = gallons/hour at WOT. To much depends on boat type, engine state of tune, hull cleanliness, water conditions, etc. You should really consider 1/3 of your fuel load outbound, 1/3 fuel load inbound, and 1/3 reserve. To put that another way, if you have a 40 gallon tank, your 140 HP engine would use roughly 14 gallons in one hour outbound. It would use another 14 gallons inbound. That's 28 gallons leaving you 12 in reserve that must cover your trolling time and any emergency. You really need to make some test runs to determine actual fuel consumption numbers with what you consider an average load. Either that or install a fuel flow monitor system if you are going offshore.
