Fuel consumption this past weekend for the old 400DA gasser...

[rondds]

George
What was the RPM you ran to attain 28gph? That is surprisingly low but I guess the numbers don't lie. Someone once posted the dyno numbers for these motors. The only difference, from boat to boat, would be the speed you get at each RPM, based on weight, wind resistance, clean bottom, etc. At 28gph I'm chugging along at around 19mph with full fuel and ZERO wind and current. BUT, remember, idle and displacement speeds do create more favorable bottom line numbers, even if you were running at that speed only 5% of the time.

I consistenly average about 14gph for the season with all the no-wakes around here. But at cruising speed in real time, the floscans and totalizers do not lie and I'm up at 32gph.

 

[thebig4-0]

"George

What was the RPM you ran to attain 28gph? That is surprisingly low but I guess the numbers don't lie. Someone once posted the dyno numbers for these motors. The only difference, from boat to boat, would be the speed you get at each RPM, based on weight, wind resistance, clean bottom, etc."

Ron:
I believe that I was at about 2150 rpm, but I am not absolutely certain on that. When I say 5% of the time for the idle time, I am probably exaggerating a lot, because really we travelled from Lake St. Clair, down the Detroit River, across to Sandusky, up the entire U.S. shore of Lake Erie, and across the lake from Dunkirk to Port Colborne, and we were always at cruise speed - did not vary at all more than 1 mph (probably half that) the whole way, except to stop for fuel, and I cruised it to the harbour every time. One exception is about 3 miles in to Ashtabula when I hit some fog. I was doing 13 to 15 mph then though thanks to the radar (i.e. not an idle). The entire trip was cruise speed. Because I had never had twin screws, or anything near 40 feet to captain, I even cruised right past Put-In Bay at cruising speed, because I was limiting my docking experiences to a minimum. We had to make it home in 3 days if at all possible.

I also had a freshly cleaned and painted bottom and we kept the water tank down just below a quarter. We had two newly tuned props on her. We had virtually all of our boat gear and galley was stocked already (went on a shopping spree in Harrison Township).

Fuel was always topped at each stop, which amounted to fuel stops in Detriot, Sandusky, Ashtabula. Our last fill was when we got to Port Colborne on the Canadian side (at the Welland Canal) and again I was able to tell him from the top of my head within five gallons what to put in the tank. I had even figured out the difference between the two sides was about 2% by that last stop. (And I am NO genius!)

By the way - Sandusky, at the amusement park's marina, was the cheapest fuel by far... This was surprising! I guess they have different people running the marina vs. the hot dog stands and candy corn. (The transient docking was actually the most expensive though).

 

[Searaybio270]

George,

Thanks for the info. I have a 400EC 1996. Just got it so I can't tell you what I am getting. However, I will track it this summer.

I'll keep you and everyone else posted.

 

[rondds]

George
You typed 2150 but I'm guessing you meant 3150...right? If it's 2150, you better check under the hood again b/c I think you're going to find white engines, not the black ones the rest of us have!

Did you do your calculations the old fashioned way? ie: start with a topped off tank, clock engine hours during a run, top off again and do the division? Or do you have GPH monitoring on the boat? Spec sheet shows your published dry weight at 16100lbs, which is 400lbs less than my tub. That could be the difference. I'm not trying to discredit your calculations - I'm just trying to figure out why our numbers are VASTLY different.

http://www.searay.com/boat_graphics/electronic_brochure/company1729/1C1_27_74DERNRPM826.pdf

 

[Jimmy Buoy]

"George

What was the RPM you ran to attain 28gph? That is surprisingly low but I guess the numbers don't lie. Someone once posted the dyno numbers for these motors. The only difference, from boat to boat, would be the speed you get at each RPM, based on weight, wind resistance, clean bottom, etc."

Ron:
I believe that I was at about 2150 rpm, but I am not absolutely certain on that. When I say 5% of the time for the idle time, I am probably exaggerating a lot, because really we travelled from Lake St. Clair, down the Detroit River, across to Sandusky, up the entire U.S. shore of Lake Erie, and across the lake from Dunkirk to Port Colborne, and we were always at cruise speed - did not vary at all more than 1 mph (probably half that) the whole way, except to stop for fuel, and I cruised it to the harbour every time. One exception is about 3 miles in to Ashtabula when I hit some fog. I was doing 13 to 15 mph then though thanks to the radar (i.e. not an idle). The entire trip was cruise speed. Because I had never had twin screws, or anything near 40 feet to captain, I even cruised right past Put-In Bay at cruising speed, because I was limiting my docking experiences to a minimum. We had to make it home in 3 days if at all possible.

I also had a freshly cleaned and painted bottom and we kept the water tank down just below a quarter. We had two newly tuned props on her. We had virtually all of our boat gear and galley was stocked already (went on a shopping spree in Harrison Township).

Fuel was always topped at each stop, which amounted to fuel stops in Detriot, Sandusky, Ashtabula. Our last fill was when we got to Port Colborne on the Canadian side (at the Welland Canal) and again I was able to tell him from the top of my head within five gallons what to put in the tank. I had even figured out the difference between the two sides was about 2% by that last stop. (And I am NO genius!)
quote]


Before we all get too amazed at fuel burn numbers here, let's take into account one factor that only someone familiar with the area would know.

Water passes through the Great Lakes in one direction constantly (from lakes to ocean). If one travels with the current say from Lake St Clair to Sandusky, it will provide skewed fuel burn numbers since the current does some of the work getting you to your destination. The only true way to get meaningful numbers is to complete a round trip back to the starting point. You will find the numbers heading against the current aren't so great, but when averaged with the first leg, will give you a more accurate representation of performance.

Heading South on the Detroit river at idle will get you going about 8Kts, but turn around and go North and you will be losing ground at idle - just due to the current.

 

[Whitenights]

I get avg of 34 gph at around 3400rpm doing 22-23mph. about .65 mpg. I really need a tune up it sounds like if you guys are getting more with bigger boats. I do turn full 4400 rpm so my props must be sized right.

 

[rondds]

Jimmy
George said he averaged the same numbers all last season, which, I'm sure, involved trips in both directions (with and against the current).

Whitenights' numbers are more like mine (other than the speed) and more like a friend with a 95 370DA with same engines. Boats this size and weight just don't do much more than 0.70MPG at cruise. I'm no expert but you usually have to go to the smaller boats, like a late 90s/early 00s 330DA or 340DA, to get up above that MPG number. Main reasons are the narrow beam and lighter (by 2 tons) dry weight.

 

[Air O'Nautical]

This time last year I gave my father my Four Winns 267 Quest and moved up to a 1995 Sea Ray 400 Express Cruiser with twin 7.4 L / 454 Merc's (carb's obviously being a 1995). The boat was purchased from Scott Hossack at Hideaway Yacht Sales in Harrison Township, MI. I highly recommend Scott as an honest and straightforward sales guy. I'm a salesman so I appreciate his approach.

Anyways, I had Ron at First Mate Marine do all of the mechanical, except a basic tune-up and oil changes that I did myself. Ron made sure that the running temps were exactly in spec before I left to bring it back to St. Catharines on Lake Ontario, among other things, which took some work, including replacing one of the thermostat housings. (By the way - Ron is absolutely awesome - knows his stuff and doesn't charge you an arm and a leg!!). The result of tuning the boat up and using my spidey senses to find the "sweet spot" at a cruise seemed to really help me, because on a three day trip from Lake St. Clair, through the Welland Canal, to Lake Ontario yielded a 28 gph fuel burn at a 23.5 mph cruise. (GPS speed used to calculate using a Raymarine C120 plotter).

We were about a half day behind a rain storm, and my wife and I had water flat as glass the whole way home (May 24th weekend 2010). That helped with the fuel burn, but we also had some foggy stretches here and there, and some slight headwinds here and there, etc. I had never run that boat (or anything bigger than 27 feet for that matter!) before, and I never trust a fuel gauge in a boat, so we topped the tanks several times by the time I pulled in to Ashtabula Ohio to fill up. By then, the fuel burn was so predictable I told the guy within 5 gallons what we'd need on a half full tank and I was right on the money. I did not include the Welland Canal so the numbers are a good indication of a trip that is 95% set at the same cruise speed, save for docking and some traversing of harbours like Ashtabula and Sandusky, etc.

I have averaged the same fuel burn all last season on trips, so I don't know why people are showing much higher fuel burns on this forum(?). Maybe I just got lucky on this one!

I never had a chance to calculate fuel burn at a much lower rate of speed because the lake always seemed to whip up half way home, and for the sake of comfort I'd pick it up a notch. I'll try again this season.

By the way - I was just at the Toronto Boat Show, and with the exception of a couple of 50+ cruisers, not one of the boats I saw this year impressed me with the layout now that I am used to my 400 EC. I can really appreciate this fine boat now that I have had it for a season and compare it to million dollar yachts!

I agree with what a great layout we have with the 400EC.
You will need to go up to at least an older 45 to get more room.

My fuel burn is higher than you are reporting.

What RPM are you running at cruise?
Speed?
Do you know what props your spinning under there?

I cruise between 3000-3500 rpm.
Normally see 18-23kts.
Burn has been as high as 48gph with a scummy bottom and loaded to the max for vacation.
Thanks,
Mark.