1.8 MPG - Typical?

I do not calculate my mileage on the boats at all. In fact, when I gas up, I fill up, hand the card over to the attendant and sign the receipt. I dont care to look to see how much I am spending on gas.

Ive always said, if you have to ask how much, then its probably not for you...

Maybe the "youngness" is going to show, but since when do people calculate MPG on a boat? Isnt it GPH (Gallons Per Hour), that is mostly measured in...?

Measure in GPH, and youll get better numbers :)
 
John,
I run a 290 Sea Ray w/ twin 4.3EFI's and BravoIII drives, I get 1.5 to 1.8 depending on load, speed & etc.. I'm guessing you are spot on. Enjoy & don't worry about fuel burn. Judge by beers per mile.:-)
 
quote:
Originally posted by BoatCrazy

I do not calculate my mileage on the boats at all. In fact, when I gas up, I fill up, hand the card over to the attendant and sign the receipt. I dont care to look to see how much I am spending on gas.

Ive always said, if you have to ask how much, then its probably not for you...

Maybe the "youngness" is going to show, but since when do people calculate MPG on a boat? Isnt it GPH (Gallons Per Hour), that is mostly measured in...?

Measure in GPH, and youll get better numbers :)

Click to expand...


GPH is the best marine gage, however, MPH is something that many relate to, especially some of my land lubber friends or even non boating guests. I get this so often, how far is X place we / you are going ? When I tell them and what I average at cruising speed they draw a blank face because they can’t believe what I just told them or they are trying to do the math based on the current gas prices. Then I tell them the price on the water is a bit higher. Then, please put away your $10/20, the trip is on us. Sit back and enjoy.
 
quote:
I do not calculate my mileage on the boats at all. In fact, when I gas up, I fill up, hand the card over to the attendant and sign the receipt. I dont care to look to see how much I am spending on gas.
Click to expand...


Regardless of cost, it's important to understand how much you're burning if you're doing any kind of trips so you know what you're range is. When I'm heading offshore I need to know how far I can safely run and make sure I have plenty left in the tanks to get back!
 
I think MPG can be an effective way to measure fuel use depending on what you are looking at.
For example: I will use more gas to get from point "A" to point "B" if I am going fast than I would if I cruised between the two spots at 5 mph. It will take me a lot longer at 5 mph, but it is more economical.
 
SEA RAY 340
2001
PERFORMANCE
TWIN 454 MPI

Speeds by GPS
Fuel Flows by computer connected to engines.

RANGE IS 215 GALLONS

RPM MPH GPH MPG RANGE

700 3.9 2.0 1.95 419

1000 6.0 3.6 1.66 358

1200 6.8 4.4 1.55 333

1500 7.9 7.0 1.13 242

2000 12.4

2500 18.6

3000 16.9 24.0 .70 150

3200 20.5 26.6 .77 164

3400 24.1 30.6 .79 168

3500 25.0 31.0 .80 172

3600 26.4 33.4 .79 170

3800 28.0 34.8 .80 172

4000 29.5 38.0 .77 164

4300 32.6 47.6 .68 147
 
y'all are tempting me to post my fuel burn for the trawler! :)
 
quote:
Originally posted by Woodsong

y'all are tempting me to post my fuel burn for the trawler! :)

Click to expand...


Woodsong, please do, as well as the specs of your boat. I am in long long distance planning of a Great Loop cruise, and think I am going to lean towards a trawler, mainly for the fuel burn.
 
I guess if you think one is "the" number to use, then maybe were just having some kind of Weiner texting contest.

GPH. This is a VERY useful metric that is easy to do mental math with. Over time I knew that my old 23 ran about 10 gallons an hour. Actually it usually calculated to around 8 with the single chev 350, but 10 is a very nice number. I never used more than that, even though the 300+hp motor could pull twice that at WOT. Average cruise speed numbers were what I wanted. Measuring miles traveled on the water, especially when you are not actively dead reckoning is typically not mental math. It's much easier to know that I've been travelling for exactly 3 1/2 hours at a normal cruise speed. I held 70 gallons, so at 3.3 hours I know I'm at the half way point. Using rule of thirds, I know I want to be at my destination in the next hour and a half, or start making plans for an alternative. I don't have to do calculations on wind/current or miles travelled and yet I know roughly my fuel condition at all times. VERY useful. Today on my 48 when I do fuel planning, I use GPH only now I plan around 5 gph instead of the 10. I usually use about 3.5 to 4 gph in reality. Nice conservative round numbers are the ticket.

MPG I'm in Admiralty Inlet and the current is CHUGGING (the wrong direction). In mid stream I'm losing over 4 knots and barely making headway. Should I speed up? Will I actually save fuel by getting out of the stream quicker? How much fuel is raising my speed by a half knot costing me? I'm going to Canada and back a few hundred miles and I want to complete the trip without buying fuel. The faster I run, the worse my economy.

If you want to measure "efficiency", then MPG is the ticket, not GPH. MPG requires a bit more match, but I solved the problem by adding floscan's coupled to my GPS so I put away the calculator and just look at the result. If I'm really trying to conserve fuel, I'll run about 1300 rpm's and if the current is not against me than I'm seeing 2.4 mpg (maybe more). In fact, I'll budget 2.0 for my mpg plan for the trip. I'll then match the boat speed to hit that 2.0, so long as I am free to take a little more time if needed. MPG is the tool of choice.

There is no one perfect measure. Knowing what you want to accomplish is more important. Being able to know which you can use to do instant mental math to make realtime decisions upon without a calculator is even more important.

Use every tool availble to you and know which tool you want.
 
Ghost, well put. I enjoyed that read.

I just find it kind of hard getting an accurate account of fuel mileage. You can use the floscans, but if its anything like the computer in the cars that tell you the fuel mileage, then its going to be off about 5-8% atleast thats my experience with the cars.

A car company can come out and say well this model with this engine gets 19mpg around town and 25mpg on the highway. Wind will effect that mileage, and traffic of course. Also, it depends on how hard you are on the gas.. With a boat, there is nothing aerodynamic about a boat, you have a bimini up, that will slow you down. On a boat, you have wind, current, sea conditions, etc..

On a day when its blowing 15knotts and you have to push your motors a little more then usual because of the current or wind..say you get 2.0mpg that way. Other days it could be perfect conditions, very little current, no wind, calm seas and you get 3.2mpg.

Are you going to average those two days out and get your final number?

Maybe I do things the old fashion way. I still do the GPH. I know what my engines burn an hour, and and I know what my tank holds. I add 4 gallons per hour to each engine, as a "safety" or a "reserve"

What did we all do before floscans?? To me, floscans take something away from boating. IMHO Its just another electronic gadget to have..
 
As stated in my posts above I use both GPH / MPH so Ghost hit the nail. Well put. Tonight baring a major T-Storm like last night, we are heading to Atlantique. I know the trip dock to dock is about 11 miles and most all at cruising speed. Based on my Flow scan that I keep the cover on now, I am burning about 31GPH doing about 22-26MPH. The trip usually takes about ½ hour give or take. Based on GPH, I would have burned about 15 gallons to go 11 miles. I guess that would be .73 MPG.

Wow I think I am going to go slower, what’s the rush ;-) Unless the T-Storm is on my tail.
 
Our old boat gets ~ 1 MPG at 16 MPH, including generator.
 
twin 5.7 30' Sea Ray. Over a tank of gas I average 10 to 12 gph. This is a mix of no wake and cruising at 2800 to 3000 rpm. 18 to 24kts. Gas prices are important. What this means is I go for an hour, spend a day on the water, anchor somewhere for about $100 at today's prices.
 
the most important measurement is FPT....... fun per tank. you should be getting a lot.
 
You must log in or register to reply here.
Back
Top