TomCat Range
- Thread starter Nushagak
- Start date
Under ideal conditions on a plane you can get slightly over 2 mpg (2.2 statute mpg) was the best I did on inland waterways on a run of about 200 miles. That was with Suzuki 150's, and cruising in the mid 20's to low 30's. But my boat was fairly heavily loaded with air conditioner, full water, full fuel (to start). cruising gear and supplies.
The fuel tanks "hold" 75 gallons each, but usable is a little less. The pickups are fairly well aft in the tanks, and I feel usable is closer to 140 gallons.
Hopefully Brent will pop up and give his displacement mileage. Roger does a lot of offshore fishing trips, as do a number of other members.
The Boat Test.com gave a range of close to 600 miles at 6 knots, and ranges of 375 at 18 knots--they gave fuel capacity of 130 gallons.
There is a lot of information so hang in and see what others have gotten.
The fuel tanks "hold" 75 gallons each, but usable is a little less. The pickups are fairly well aft in the tanks, and I feel usable is closer to 140 gallons.
Hopefully Brent will pop up and give his displacement mileage. Roger does a lot of offshore fishing trips, as do a number of other members.
The Boat Test.com gave a range of close to 600 miles at 6 knots, and ranges of 375 at 18 knots--they gave fuel capacity of 130 gallons.
There is a lot of information so hang in and see what others have gotten.
Pacificcoast101
Member
With Honda 150s we get a little over 200 miles before filling up. We set 125 gallons as our safety limit because we ran out of gas on one motor about a mile from the fuel dock the first time. With dive gear and three people we average between 1.6 and 1.7 mpg. If the ocean is flat we can get more than 2.0 but that is rare.
The fuel dock at our marina in Redondo Beach charges $5.80 per gallon while we pay $3.50 in Los Angeles Harbor. We travel 18 miles to get gas, but we save close to $300 by going there as well as get the chance to dive some of the sites that are beyond our usual treks.
The fuel dock at our marina in Redondo Beach charges $5.80 per gallon while we pay $3.50 in Los Angeles Harbor. We travel 18 miles to get gas, but we save close to $300 by going there as well as get the chance to dive some of the sites that are beyond our usual treks.
Thanks for the input. I appreciate it. I read the posted preformance spec's on C-Dorys web site. I wondered if they tested with a light boat.
Test done with twin 150 Honda 4-strokes.
3000 RPM, 20 MPH, Fuel burn 6.4 gph, 3.2 mpg, range 375
4000 RPM, 31 mph, fuel burn 13.1 gph, 2.37 mpg, range 278.
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Test done with twin 150 Honda 4-strokes.
3000 RPM, 20 MPH, Fuel burn 6.4 gph, 3.2 mpg, range 375
4000 RPM, 31 mph, fuel burn 13.1 gph, 2.37 mpg, range 278.
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gulfcoast john
New member
You bet they always test with a light boat for the best possible numbers. Fair enough.
With Yamaha 150's, 4 blade 17 pitch aluminum props between 3000-4000 RPM, heavy cruise mode (scale rig wgt of 11,860# with 1/2 gas and no water, EOH trailer is 2,000#) we avg 1.7-1.9 MPG combined. Bimini, bottompaint, non-pristine bottom, poor loading, poor trim (likes a lot of trim up mostly) costs. Rarely we get 2.4 MPG in ideal conditions with a tailwind and current when barely on plane, but not long enough to say, 'hey, look at that MPG!' before dropping back to 1.9. Also, when just barely on plane you'll get knocked off it by a wake or a turn or a wind or trim change, so we tend to stay at 3,500-4000RPM. Above that we abruptly start sucking down up to 31 GPH rather than 13.2. Real gas contains more energy than E10 if you can get it. Full tanks are 900 lbs of gas, and you'll feel that in a 26 ft boat. The counter rotater engine is less efficient due to extra gearing, plus Yamaha claims a 15% difference between identical engines is normal.
You can get much better mileage with one engine off and the other at 1800-2000 RPM, but if you like that kind of boating then buy a Ranger 27 and get 5 SF more cockpit space with a single diesel and a wine chiller, assuming you're the only non-fisherperson in Alaska.
Happy shopping!
John
With Yamaha 150's, 4 blade 17 pitch aluminum props between 3000-4000 RPM, heavy cruise mode (scale rig wgt of 11,860# with 1/2 gas and no water, EOH trailer is 2,000#) we avg 1.7-1.9 MPG combined. Bimini, bottompaint, non-pristine bottom, poor loading, poor trim (likes a lot of trim up mostly) costs. Rarely we get 2.4 MPG in ideal conditions with a tailwind and current when barely on plane, but not long enough to say, 'hey, look at that MPG!' before dropping back to 1.9. Also, when just barely on plane you'll get knocked off it by a wake or a turn or a wind or trim change, so we tend to stay at 3,500-4000RPM. Above that we abruptly start sucking down up to 31 GPH rather than 13.2. Real gas contains more energy than E10 if you can get it. Full tanks are 900 lbs of gas, and you'll feel that in a 26 ft boat. The counter rotater engine is less efficient due to extra gearing, plus Yamaha claims a 15% difference between identical engines is normal.
You can get much better mileage with one engine off and the other at 1800-2000 RPM, but if you like that kind of boating then buy a Ranger 27 and get 5 SF more cockpit space with a single diesel and a wine chiller, assuming you're the only non-fisherperson in Alaska.
Happy shopping!
John
Running at 3800-4000 RPM we get 2.0 MPG + or - depending on the load. That's at about 20 MPH. 2006 Honda 135's fuel injected. 3 blade SS Honda 17 pitch props, or 4 blade Aluminum props. I'm not sure on the pitch of the 4 blade's. Each prop seems to be about equally efficient. I bought the 4 blade's to use in Alaska in 2015, and just haven't taken them back off.
We often run at 1800 RPM on one motor at a time, alternating to keep the engine hours equal. This gives us about 5 or 6 MPH and around 5 MPG. We did this in SE Alaska in 2015. We tried to run with the current and tides as much as we could. 1800 RPM on the Honda 135's is our sweet spot. Around 1 GPH per motor. Running one motor we do 5 MPH with both running together it's 7 MPH. Depends on wind, current, tide etc.
This summer we did the Trent Severn Canal. 240 miles each direction. We turned around and did the canal both ways. 90 locks and about 500 miles covered. We used the one motor technique most of the time. The exception was Lake Simco which was rough both times we crossed it. 16 miles each direction and we got up and ran 4000 RPM and 20+ MPH. We did the summer trip on the single fill up at the start of the trip.. 150 gallons in theory. It was looking close at the end, but I haven't filled up since to see how close to out we were.
I run with Twin Scan fuel flow meters. They have proven to be accurate within 1% over the course of over 1000 hours on each engine. The fuel used is the combined total of both motors. If I keep the hours even, I assume the motors are using about equal fuel consumed. If the meter indicates I have used 100 gallons, it always takes 99 to 101 gallons to fill the tanks.
I just went out to the boat and looked at the fuel flow meter. 132.9 gallons used for the 8 weeks we were on the Trent Severn and the Mississippi River gathering. We probably went 510 miles total. 3.84 MPG with a combination of mostly slow cruising, but at least 32 miles at 20 MPH or faster. I have the trip logged on the iPad Navionics program. I'll try to total the log.
We often run at 1800 RPM on one motor at a time, alternating to keep the engine hours equal. This gives us about 5 or 6 MPH and around 5 MPG. We did this in SE Alaska in 2015. We tried to run with the current and tides as much as we could. 1800 RPM on the Honda 135's is our sweet spot. Around 1 GPH per motor. Running one motor we do 5 MPH with both running together it's 7 MPH. Depends on wind, current, tide etc.
This summer we did the Trent Severn Canal. 240 miles each direction. We turned around and did the canal both ways. 90 locks and about 500 miles covered. We used the one motor technique most of the time. The exception was Lake Simco which was rough both times we crossed it. 16 miles each direction and we got up and ran 4000 RPM and 20+ MPH. We did the summer trip on the single fill up at the start of the trip.. 150 gallons in theory. It was looking close at the end, but I haven't filled up since to see how close to out we were.
I run with Twin Scan fuel flow meters. They have proven to be accurate within 1% over the course of over 1000 hours on each engine. The fuel used is the combined total of both motors. If I keep the hours even, I assume the motors are using about equal fuel consumed. If the meter indicates I have used 100 gallons, it always takes 99 to 101 gallons to fill the tanks.
I just went out to the boat and looked at the fuel flow meter. 132.9 gallons used for the 8 weeks we were on the Trent Severn and the Mississippi River gathering. We probably went 510 miles total. 3.84 MPG with a combination of mostly slow cruising, but at least 32 miles at 20 MPH or faster. I have the trip logged on the iPad Navionics program. I'll try to total the log.
journey on
New member
Just a comment on counter-rotating motors. They use the same number of gears as a normal rotating engine. The efficiency of the engines are the same.
Looking at the Honda, the engine output shaft is a bevel gear which drives 2 gears on the propeller output shaft, for both normal and counter rotating engine. For a normal engine the front drive gear is selected by a dog clutch and drives the boat forward. For the counter rotating motor, the rear/aft gear is selected and with the correct prop the engine is driven forward. The shift shaft and dog clutch shifter is different and the rest is the same
So, the only difference between the 2 engines is that in one you're driving the boat in the front gear to go forward and to reverse the propeller direction (counter rotating) you're driving in reverse.
I've not had a Yamaha outboard, but I'll bet the lower gear cases are the same size, precluding adding any extra gearing.
Boris
Looking at the Honda, the engine output shaft is a bevel gear which drives 2 gears on the propeller output shaft, for both normal and counter rotating engine. For a normal engine the front drive gear is selected by a dog clutch and drives the boat forward. For the counter rotating motor, the rear/aft gear is selected and with the correct prop the engine is driven forward. The shift shaft and dog clutch shifter is different and the rest is the same
So, the only difference between the 2 engines is that in one you're driving the boat in the front gear to go forward and to reverse the propeller direction (counter rotating) you're driving in reverse.
I've not had a Yamaha outboard, but I'll bet the lower gear cases are the same size, precluding adding any extra gearing.
Boris
I tend to cruise around 20 mph and fuel flow averages around 1.9 mpg with twin Honda 150's. I consider a 250 mile range my max but always keep it under 200 miles for 'our' peace of mind.
Ethanol free gas averages around $2.80 at our local marinas and $2.20 at the local quick stops so have yet to use the non-pure stuff :lol:
Ethanol free gas averages around $2.80 at our local marinas and $2.20 at the local quick stops so have yet to use the non-pure stuff :lol:
PaulNBriannaLynn
New member
I still cant get over almost $5.80 for gas at Redondo Beach!
:shock:Pacificcoast101":22jct1np said:
Pacificcoast101
Member
They actually lowered the price last weekend to $5.40. That won't last long. It's the same price at Marina del Rey. There are times I wish I had a trailer. 
I just watched the iDock video from Evinrude. Someone should buy the TomCat Wefing's listed in another thread , and install two 150 etech's and the iDock system. Ultimate for a new TomCat
https://www.youtube.com/watch?v=28L..._list&utm_term=sec2|0|0&utm_content=0|0|0|0|0
https://www.youtube.com/watch?v=28L..._list&utm_term=sec2|0|0&utm_content=0|0|0|0|0
Thanks to Brent and Dixie and others for posting their slow cruise mpg with the Tomcat. We love this boat design for it's roominess and stability, but 2mpg or less is daunting. I have been curious as to what the slow cruise potential of this boat is and it's good to get some real numbers. I am guessing the fuel usage goes way up beyond 1800rpm? I would like to cruise at 8mph with good economy and then would not care about the fuel burn for those times when I need to go fast. But 5mph feels a bit draggy. Any real world usage numbers are most appreciated.
With the Tom Cat at 8 mph you are really dragging the bridge deck as a wave forms. I found when traveling with trawlers who wanted to go 8, I would step up on a plane, and then find a place to drift or anchor waiting for them to catch up.
At that speed (and the RPM with vary with the props, & gear ratios in the lower units, you are probably in the 2.5 to 3 mpg. Might be better with a long skinny diesel powered trawler type for economy.
But in AK and many other scenic areas, there is a lot to be said for the slow speed. Most of my Alaska time was in our Cal 46 and we were running at 6 knots. (6 miles per gallon). You enjoy the scenery.
At that speed (and the RPM with vary with the props, & gear ratios in the lower units, you are probably in the 2.5 to 3 mpg. Might be better with a long skinny diesel powered trawler type for economy.
But in AK and many other scenic areas, there is a lot to be said for the slow speed. Most of my Alaska time was in our Cal 46 and we were running at 6 knots. (6 miles per gallon). You enjoy the scenery.
The sweet spot for the Honda 135's is below 2000 RPM. At 8 or 9 MPH you are just mushing along. Using the same fuel that you would at 18 or 20 MPH. 8 to 12 MPH is the worst you can do with our TomCat. Either go slow at 5 or 6 MPH or get up on a plane which occurs above 15 MPH depending on the load. The TomCat is not an 8 MPH boat.