Gas Milage? 35-90hp motors?

[Bunnerrabbit]

Just wondering if there is a certain size or year you need to get to to get a motor with better gas milage? Im starting to look for a boat and with todays gas price's i dont want something thats just going to drink it down faster than i can put it in. My first boat and I had to sell it was a 86 16ft Alu Bass Tracker with a 35HP mercury drank the gas super fast for its small size. It was a good running motor and the boat only had a 6 gallon tank but I could only get about say 50- 60 min of run time out of it maybe 30 miles. does that sound right? I have heard that larger motors get better gas milage? Also would a new 50HP motor have alot more power than my old 35hp? I have seen some 15-16ft center console boats with only a 50hp motor. are they way under powered?

 

[mattttt25]

Re: Gas Milage? 35-90hp motors?

a lot of science in the questions you ask, and hopefully you'll get some good answers. not really true that a larger engine gets better gas mileage. hp is hp and power is power. still going to take the same amount of fuel and air to produce the same energy, regardless of the size of the engine.

 

[biloxiriver]

Re: Gas Milage? 35-90hp motors?

As I understand it the norm burn rate is 10% per hour at Wide Open Throttle (WOT); that should mean 3.5 GPH for your 35. I have operated various Yamahas, Johnson/Evinrudes, Force from 9.9 hp up to 112 and found this to be fairly accurate. But I must be honest and tell you I have never owned a Mercury. I have been told that newer 4 strokes do better.

 

[rwcreigh1]

Re: Gas Milage? 35-90hp motors?

i have a 17'tracker with a 84 35hp.it get good gph.and is pretty fast.it will just about keep up with my father in laws 90 hp but with half the gas

 

[Bunnerrabbit]

Re: Gas Milage? 35-90hp motors?

The motor ran good right around 30MPH

 

[beniam]

Re: Gas Milage? 35-90hp motors?

Bunnerrabbit<br />Here some info from midsized Nissan motors, I calculated from their data. All motors are newer.<br />Savings of TLDI over conventional two stroke:14%<br />Savings of four stroke over conventional two stroke:27%<br />If this is accurate for older 2 strokes, dont know. Ditto other manufacturers.<br />Be happy, enjoy life, boat lots. Batavier

 

[roscoe]

Re: Gas Milage? 35-90hp motors?

If your were getting 5 miles per gallon, that was pretty good.<br />edit- No wait, that don't sound good at all, should be double that on the mpg, and the tank should have lasted 2 hours.<br /><br />With a larger motor, like the 90 on the boat in your other post, you would have the power when needed, but could throttle back to say 3700 rpm and still cruise pretty well, about 25-30 mph and still only use 6 gallons per hour.

 

[Boatist]

Re: Gas Milage? 35-90hp motors?

Heavy boat = More Fuel Useage,<br />Lighter boat = less fuel useage.<br />Deep V = More fuel useage.<br />Flat bottom = Less fuel useage.<br />New 4 stroke = less fuel useage.<br />New 2 stroke fuel injected = Less fuel useage.<br />Old 2 stroke caburated = much more fuel useage.<br />Bigger motor at WOT = more fuel useage.<br />Smaller motor at WOT = less fuel useage.<br /><br />OK a small motor on a boat that has to run at or very near WOT to get on plane may use more fuel than a slightly bigger motor that can reach a clean plane at 3000 RPMS. However run the bigger motor at WOT and it will use more fuel. <br /><br />Most boats get best fuel mileage at idle speed to 1000 rpms then go down in mileage as throttle is increased until the boat reaches a clean plane. When the boat reaches a clean plane this will be point likely to get best crusing mileage. Increase the throttle from this point and the mileage will go down as throttle is increased.<br /><br />Boats that will reach a clean plane at 2500 to 4000 rpms will usually get best fuel mileage in this range. Take the motor up to WOT and you get speed but poor fuel mileage.

 

[Canuck 16]

Re: Gas Milage? 35-90hp motors?

Man, if you were only getting 50-60 min out of a 6gal cruise-a-day, with a 35hp motor, something was way way wrong!<br /><br />Cheers... Canuck 16.