How do you get the most out of a gallon of gas?

J

JamesTXSD

Active member
With discussions of ethanol, rising fuel prices, altering travel plans, and what our boats really get for mileage, this thread is for tips on what you do to get the most out of each gallon of gas.

Of course, slowing down makes a BIG difference with our boat. We can get better than 5 mpg if we run at displacement speed, dropping to less than 2.5 miles per gallon if we choose to run faster. I consider that a trade off: if you're willing to pay twice as much for fuel use, you get where you're going in less than half the time. If it's the destination and not the journey... whether you're on a schedule or not... and, budget constraints. Choices.

Keep the boat light. Easy to do when we're in our home waters; not so easy when we're cruising and have to deal with the uncertainties of resupplying along the way.

Which leads me to fuel. At over 6 pounds per gallon, a full fuel tank on our 25 weighs over 600 pounds. It squats the aft end of the boat and we have to use more throttle and trim tabs to get on plane. If we are day-tripping locally, we keep the tank less than half full - no point in carrying all that fuel around when fuel is easily available. Unless, like currently, fuel is going up faster than they can change the signs at the gas stations. So, you have to "play the futures" somewhat. A balancing act.

And if you don't top off your tank all the time, your fuel use is a guesstimate at best. Another reason I like having a fuel flow meter. Use of it over the years has shown that it is pretty darn accurate. And we also use that fuel flow meter to trim the boat for best fuel burn at any particular speed or rpm.

And speaking of RPM, a couple hundred can make a big difference, especially if you are OK with traveling slow. On our boat, the difference between 1800 rpm and 2100 rpm is a 30% increase in fuel burn (1 gallon per hour vs 1.3 gallons per hour). 3/10 of a gallon per hour doesn't seem like much until you figure the percentages. Same thing applies when we are running at a higher speed - a couple miles per hour may vary the fuel burn by a couple tenths.

We try to avoid ethanol. Not easy to do anymore when the nearest station reporting that they sell "non-ethanol" gas is over 80 miles away... on land. Ethanol, besides all the nasty stuff we've discussed in other threads, is less efficient as a fuel than pure gasoline - add it to your fuel and you will get lower mpg. Swell.

So, what else is everyone doing? (NOT using the boat is not a valid consideration for some of us.)

Best wishes,
Jim B.
 
We never fully avoid ethanol but our tactic is to burn the fuel soon (all year use) and fill with fresh while treating every tank that will sit for more than a couple of days with marine Stabil.

Our favorite method of saving fuel works with twins or singles with kicker and that is running at hull speed or preferably a bit less on just one engine. Be sure to tilt the non-running engine out, or mostly out of the water to lessen drag and we try to run one motor for a few hours then the other to keep the hours balanced for maintenance reasons on the 25.

We were able to pull off mileage of around 6-7 kmpg this way at 5 knots if my estimates were correct. We didn't get anywhere fast but we were moving and enjoying the scenery and the noise level was also lower with one engine off.

Keep in mind that running on a single (twins) or kicker may result is some or all of your gauges not functioning during that time so you have to keep in mind your actual fuel/trim level or whatever indicator is not powered.

It's a good idea to exercise you kickers anyway so save a little gas while you at it. Even though we are all power boaters with relative immunity to currents, if you take into account the tide flows in your travel planning, you can also save loads of fuel in certain areas.

If we were never in a hurry, we could all just mount a 9.9 in the middle and cruise around on very little gas. Maybe twin kickers and no main for a backup.... Theres a thought, Twin engines just large enough to plane the boat if needed but running one primarily for best fuel mileage at lower speeds.

Thats why I always dreamed of twin 60s or twin 70s on our 25.

Greg
 
We slow down when possible. I rarely run over 4500 rpm's and our normal cruising is in the 3500 range. We already run pretty light.

As for our daily lives, I don't do any car/truck traveling that's not necessary and we try to combine trips whenever possible. I'm even going back to using my mountain bike for short trips in/around the neighborhood when feasible and trying to drive a little smarter/ more effeciently.

I'd love to have some vehicle like "Back to the Future" where I could put a banana peel and some food scraps in and...whamo! Energy. But alas...we've talked about a new, more effecient car but the costs involved make that a less than ideal choice, especially w/ NO car payments at the moment. I almost feel helpless when a fillup of my F-250 costs over $100. :x :roll:
 
Trim your boat to run most efficiently. We have many options with the C Dory which has both engine trim and trim tabs. Get the boat up on a plane quickly. Put the tach at about what RPM you want to cruise at. (Lets say 3500). Then bring the trim tabs all of the way up--and see how the boat handles--with the outboard in mid position. If it handles well, and seems to be trimmed well, then just slowly adjust the trim on the outboard so that the RPM's increase, but don't begin to decrease. Your speed may go up--and you may want to back down a bit on the throttle to get back down to the desired RPM (3500) in this case. If this is not working well, then give a small about of trim tab down (bow down)and see if this will have the effect of increasing the RPM. What you are shooting for is the most RPM for one throttle setting.

After going bow down for chop--be sure to trim back up for going down wind or cross wind, and in smooth water.

Be sure the bottom is clean

Check the prop--be sure it is balanced (Prop Scan). Be sure it is the correct prop--that you can achieve desired RPM at WOT and the speed which other boats are running.

Do not run at the speed between plane and displacement speed, with tabs full down and engine full down--unless there is some good reason due to the sea state.
 
While all of the above suggestions are great, I find the following helps me to get the most out of a gallon of boat gas:

1) Bring along excellent food.
2) Bring along one or more good bottles of wine.
3) Bring along one or more good friends.
4) Plan your trip to an area where and when the fishing is excellent.
5) Don't sweat the small stuff and smile at all times.
 
as mentioned, keep the tonnage down, get on plane quickly, keep the speed down and also keep an eye on the tide. If you can time your travels to go with the flow you're ahead of the game....and of course pack only lite beer.

I find it saves money to burn company gas too :) although fuel use is tracked & butt chewings have been issued. I always try to plan my fishing day to eliminate to much running around. You can do this by considering options, if species X isn't bitting at point A we can hit other species and other locations close by, or, on the return route. Some folks blaze off to some alleged hot bite in an area that offers little alternative options then end up running off to some other distant spot when the first spot doesn't pan out, I've seen some that burn up half a day running around like a chicken with their head cut off..... they don't seem to be working at my place of summer employment anymore though
 
With the combination of trim tabs & Permatrims on twin Honda 40,s I adjust for milage very similar to Bob.  Start out with a set desired rpm & speed then adjust trim for best increase of speed & rpm.  Only difference being I achieved best results by keeping the Permatrims inline with the keel & using the trim tabs to adjust for increase or decrease of speed & rpm.   Tried all other combinations & nothing else worked as well.   Of course when going into chop or being extra heavy in the stern from starting out on long cruise with additional fuel & all the other extra weight will most likely have to add additional trim to the  Permatrims.  Main point being I always received best results by keeping the Permatrims level & using the trim tabs for adjustment, which seems to be just the opposite of what Bob & others have reported.

Remembering to put all the trim back to level when going to displacement speed helps along with all the many other good suggestions, but nothing helps overall more whether in the boat, or towing the boat as reducing the speed to the sweet spot & for just saving $ the sweetest spot is displacement speed.

Jay
 
B~C":34rb7a6r said:
Some folks blaze off to some alleged hot bite...
Click to expand...

Well said Mr. B "I'm gonna run over to 1 and try hoochies on the green line" C.

Following up on what RB said, wine is now cheaper than gas, so...
 
Lotsa great advice here!

Here's what I do:

1. Keep the C-Dory in the RV Barn in the back yard and use it only for serious fishing trips, and when so doing, conservie fuel with most of the ideas above.

2. Use our 24 foot Fisher pontoon boat (kept at Bridge Bay Marina) for lake trips. Besides the fuel-efficient pontoon hulls, it has a 4-stroke 40 hp Mercury (Yamaha powerhead), which is also quite fuel efficient. Since gas at the lake is always $1.00 per gallon more than at the highest local pump, we bring 5-6 gallon cans to the lake to refuel it as necessary. (Standard El Cheapo move around here!) We can usually do a whole day on 5 gallons or less.

3. For overnights, we use our Sea Ray 265 (also kept at Bridge Bay), sometimes going out to anchor overnight, but often just staying in the marina with shore power and a roof overhead (both nice in winter). Also, some of the very best fishing in the lake is right under my boat, which is the closest one to the Pit River Bridge, and affords great views w/o moving around the lake. We also know and socialize with a lot of folks that also stay at the marina overnight, particularly in the summer months. Why go somewhere else when the best place and action on the lake is right here? Saves gas 100%!

4. When the urge to blow gas out the tailpipe becomes uncontrollable, we take our 3-place Bombardier jet ski up to the lake and ride around until the urge subsides. Usually, we use the jet ski in conjunction with one of the other boats. It will run 75 minutes on 16 gallons of gas at full throttle (50+ mph). After some phycological and economic relief, it returns home to the barn to keep the C-Dory company.

Joe. :teeth :thup
 
TyBoo":1yfjjh3k said:
<stuff clipped>
Following up on what RB said, wine is now cheaper than gas, so...
Click to expand...
Not the wine I drink. But regardless after about a 1/2 a bottle I've forgotten both the price of the wine and the price of gasoline.
 
There is a reason that I trim the way I do. That is you can use the trim tabs to balance the boat side to side--and that is what they are best at. It turns out the the motor with fin (Doelfin or Permatrim) will end up parallel to the flow of water off the bottom and that is because it is most efficient. We end up at about the same place. If the trim tabs are up then they are causing the least resistance. If you need to put one down, because you cannot balance the boat with moving crew or gear--then that has to happen.
 
My experience has shown:

1) High torque, low-rpm motors really helps.

2) Cruise with the tide! This can make a big difference. If you have one or two knots behind you, you can kick down the RPM's and just cruise at a relatively high speed. Mileage goes way up. On tidal rivers, it makes a huge difference, for example, on the Connecticut River, when I was running with a 3 knot current, I could travel 7 mph with my 4 HP 4S kicker, and its fuel consumption was approximately 1 quart per hour. On the day I took my CD 16 to have it sold, I went with a strong tide, and got 8 miles per gallon over the course of approximately 25 miles. Granted the tide was ripping, but that was a big change over the normal mileage of 5 to 5.5 mpg experienced in other, less-favorable conditions.

3) Travel in a straight line. A circuitous route will waste a ton of gas. That's why autopilots are so beneficial in that they keep the boat on line, ensuring an efficient route.

4) Trim is critical, especially for people with kickers who can make their boats too stern heavy. I found that out first-hand with my CD 16 Cruiser upon removing my heavy kicker motor.
 
Dr Bob, Perhaps this is the reason the way I do do it works best for me. Our on plane cruise speed is only 12 to 14 knots & at this lower speed it takes a higher percentage of trim then at higher speeds. Due to this we must run a very minimum 40 percent trim for best results. Being both tabs are already down this far makes it simple to adjust for side trim too while maintaining same desired bow trim. So instead of 40 percent on both tabs it will something like 60-20. Whenever trying Permatrim for bow & only useing trim tabs for side balance I would always loose speed verses the opposite.
 
We do run our boats differently. I generally run at 15 to 25 knots. Our first C Dory did not have trim tabs. It ran fine with out trim tabs, but would have been better into chop with tabs. Our C Dory 25 and the current C Dory 22 do have trim tabs. The trim tab manufactures claim that the trim tab does increase efficiency. But--they claim it is by "correcting" defects in the boats performance and balance. I have owned a number of fast power boats over the last 55 years, and only several of them have had trim tabs. In the two two moderate power trawlers they had been added to attempt to get the boat to go faster or to plane--not successful. I had trim tabs in a deep V express with an I/O which was a bit under powered, and the trim tabs were essential to get the boat on a plane--but more power and a better hull design would have been better--and more efficient.

With the C Dory 22, the boat is well balanced and efficient by design. The Trim tabs improve the ride into chop--and also will allow planing at a lower speed. This is why I feel that the C Dory 22 and 25 need trim tabs. Neither of these attributes tend to increase fuel efficiency.

It is possible that I may run this boat differently than the C dory 25, where I had a fuel flow meter (which I used regularly to judge the efficiency, and which confirmed my decision on how to trim the boat)--but I doubt it.

We all do run the boats based on our experiences and what we think is best.
 
I often limit myself to using 5 gallons of gas for the day. That gives me 20+ miles of playing which is plenty most days when I am out just whale, sea otter, and dolphin watching. I keep both tanks half full and bring a five gallon can to add alternatively to each tank. Actually all I have is a 5 gal can so if I want to go out longer I need to either hall the boat to a gas station or make two trips with the gas can. Well, I could buy another gas can but this is my method to control gas usage.

Recently I looked at a beautiful Pacific Seacraft Dana which would save lots of gas...but I would have to ignore the $85,000 price tag or else head out on an around the world cruise to save enough gas to pay for it. Wife said, "Forget it." Divorces cost a lot more than gas or even a Dana.

So burning a tad over $20.00 in fuel for a day about Sea-Cruz is very cheap entertainment. Actually less than a movie for two with popcorn and drinks. With four aboard it's $5.00 per person for gas.

Lets see movie or day on the bay in a C-Dory...IQ test.

Ron
 
thataway":26fvcvwj said:
With the C Dory 22, the boat is well balanced and efficient by design. The Trim tabs improve the ride into chop--and also will allow planing at a lower speed. This is why I feel that the C Dory 22 and 25 need trim tabs. Neither of these attributes tend to increase fuel efficiency.
Click to expand...

Which leads me to believe even in our local cruising we are slightly stern heavy & finding a way to correct this would improve our milage by reducing resistance from the trim tabs,  but in my case would have to take the flotation out of the v birth & replace it with storage to correct.  At this point not convinced it's worth doing being this kind of thing is not my forte.
 
My method of conserving fuel

use my paddle board!

Actually my fuel use changes from the pump to the table for this activity. Plus my smile is huge from all the fun I had and my body feels tight because I used it.

For the road my volt has 4000 miles and still on 15 gallons purchased. For my boating, I think that not only most of the ideas mentioned but also fishing closer to port instead of running out 12 miles to offshore reefs.

This summer I plan on enjoying fishing, surfing, target shooting and maybe panning for gold. I don't care what gas costs, I plan on having a good time!

Jeff
 
rogerbum":108cqf9s said:
While all of the above suggestions are great, I find the following helps me to get the most out of a gallon of boat gas:

1) Bring along excellent food.
2) Bring along one or more good bottles of wine.
3) Bring along one or more good friends.
4) Plan your trip to an area where and when the fishing is excellent.
5) Don't sweat the small stuff and smile at all times.
Click to expand...

Sounds like the voice of experience... :wink Great advice. Like others say keeping it light is always a good idea when practical.
 
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