Towing for Mileage

C

Casey

New member
I'm appealing to the C-Brat Brain Trust for ideas.

It is clear that we're once again about to turn the corner on $4/gallon gasoline, and one of these days we're not going to see a seasonal retreat in fuel prices. Frankly, I expect we'll $5/gallon gas by 2012 considering economic factors and coming oil production realities - but I'm getting off topic.

Having trailerable cruiser's is Great; but it certainly tempts us to wander afar and see new places. Depending on where one chooses to cruise it is quite possible to spend as much (or more...) traveling to your distant launch ramp as you spend on boat gas. For instance - ask Pat & Patty how much they spent on truck fuel versus boat fuel during their annual trips to Lake Powell!

I suspect many of us are of an age we just admit we're living our Dream's, and opt to go-for-it. Period.

But what can we do to improve our towing fuel mileage?

Oh, I know most of the usual stuff about slowing down, keeping the tires pumped up, and lightening the vehicle and trailer loads. What ELSE is there that we can be doing??

I find that the boat tows very well at 65 or so (sometimes a little faster, but don't tell the highway patrol...). I also suspect I'm killing my mileage by doing that, but in my vehicle the engine doesn't really seem to be getting into it's best torque curve until I reach the higher speeds. The truck (2010 F150 with 5.4L gas engine with a 3.73 axle) has a "hauling/towing" feature on the transmission that alters the shifting characteristics for towing. It performs beautifully, and I use it all the time, but I wonder if I need to be using it ALL the time, or just when the engine is under increased load (ie. up hill or getting up to highway speed). Right now I'm getting about 17mpg (highway) with no load and about 10-11mph towing. Any ideas or suggestions?

I wonder if slowing to a 50mph tow speed would result a meaningful increase in mileage given the vehicle and load. Again ... I wonder if the tow/haul feature is vital, or is it trading performance for mileage?

Best,
Casey*
The Villages, FL
*...still hoping for a Southeast AK summer (trailer to Prince Rupert then launch).
 
Within reason remove stuff from outside the boat-tow rig, Aerodynamic issues absorb lots of energy. When we put RADAR on top of our boat we lost 1/4 mpg on the hiway towing while the boat.

WE tow our 22 C-Dory with a 4.0L Ranger at 60 mph to save fuel. This yeilds 14 mpg.

Are the brakes or bearings dragging?

As always, keep the weight under control.

How aggressive are the tow rig's tires? This can affect milage too.
 
We'll put the dinghy in the truck bed, slow down a tad, check tire pressure etc...but outside of not driving, there's not much I can do about an 8 cyl diesel pulling a 25' on a trailer.
 
Putting a cap on your truck bed can make a significant difference. I'm not sure how much with the boat which is fairly aerodynamic but with our "land yacht" trailer which has the aerodynamic profile of a brick, it makes 3-4 mpg difference.

All that for 2c.

Merv
 
If you have an automatic transmission, it is important to tow your boat in the manner indicated in your manual. Some vehicles must be in a specific gear for towing, which will usually result in slightly higher engine RPM. If you don't have it in the correct gear, the torque converter will not "lock up", generating excessive heat, that will over time cause premature failure of your transmission. It is possible to get transmission oil so hot that it will boil and blow past your seals, resulting in further damage as the transmission runs without sufficient oil.
 
The mileage i get towing either Journey On or the travel trailer with the 3/4 ton Ford is 8-9 mpg and that's been consistent over 4 trucks. So getting a smaller truck isn't going to help, it's just that you're hauling a heavy boat..

The only thing I believe would save gas (increase mileage) is slowing down to 55 mph. That's from 60-70 mph. Remember, wind resistance increases as the square of the velocity. The wind resistance at 65 increases by ~50% over 55. Wind resistance at those speeds is the primary load that changes, since the rolling and mechanical friction is relatively constant over that range of speed.

That said, 55 is 15 to 20 mph slower than the normal flow of traffic and I feel uncomfortable doing that. 60 is reasonable but as those semis blow back it's hard not to increase your speed to something approaching their speed. And that drops the mileage back down.

I guess I'll try to slow down this summer and hold it down.

Boris
 
I'm wondering if maybe you are stressing too much. Beyond the common sense stuff our dad's taught us (and you and others are mentioning), I don't think there is much you can do to increase mileage significantly. There are tricks and chips you can do to the engine controls, but they may cost more than they save if they shorten the life of the components.

If I am vigilant for the entire tow from home to the San Juans, I might save enough to get a Burger King Double Whopper. I figure if I skip the OCD while driving and skip the Whopper too, the initial cost is the same and the future health costs are reduced.

When you think about it, pulling over at the rest stops to check trailer hub temps and look over the load uses way more fuel to get back to freeway speed than staying at speed in the first place. Maybe the best bet for fuel savings is to minimize stops. But is it the best idea? Not for me. I do my stressing over that stuff.

About the tow/haul. I don't understand all I know about it, but I do know that on my Dodge it seems to disable the overdrive. I use it if the truck is shifting frequently or going through curves requiring a lot of speed variation or going up and down hills. Just running down the road at even speed and load I think it is best to have it off.

Nevertheless, I'll be watching the replies because it is a worthy exercise and I am a comparative novice at towing. I know in years past, J.C. Whitney sold this remarkable little device called a fuel ionizer that stuck magnetically to the fuel line and gave a 30% increase in economy. And it only cost about as much as today's Whopper. Maybe somebody knows of one for diesel rigs.
 
With our GMC w/Duramax, I find the "sweet spot" for fuel mileage is just above the point it shifts into 6th gear; on our truck, that is about 62 mph. At that speed (on our truck), the transmission doesn't hunt. I don't use the tow/haul mode other than slowing down, but I do use the manual shift mode to make sure the engine/transmission don't lug. I use the cruise control unless we are in busy traffic or hilly terrain. Joan is very good about checking and maintaining tire pressure. We do use a bed tonneau cover (solid fiberglass) whenever we aren't towing the 5th wheel... I think it helps with mileage, and it gives us reasonably secure storage.

I use the Where app on the Droid to find the best price for fuel while on the road. We've run into 20¢ per gallon price differences within a few blocks... that helps, too.

KInda makes you feel sorry for those guys who don't have trailerable boats and have to get 1-2 mpg getting their big boats to the next great cruising area. :wink:

Best wishes,
Jim
 
My first trip to Florida, I had the original tires on my 2-axle trailer, and only about 1,000 miles on the tires. About 900 miles from home, I noticed the tires were bald for about an inch, on both the left sides. I replaced all four tires with radials, and had the axles aligned; they were 3/4-inches out of alignment. This increased my mileage from 9.5 to about 11 mpg, and I've come to Florida now 4 times, with no noticeable wear on the tires.
 
Check out the scan guage II. A small computer that works with almost all vehicles (Gas or Diesel) made in 1996 or later. It simple plugs into the On Board diagnostics port (OBDII port is reguired by law to be within three feet of the steering wheel). and reads (displays) all the data that your vehicles computer sees. It will scan when a check engine light comes on, show the codes and can reset the check engine light on most vehicles.

http://www.scangauge.com/products/

You can buy an extra cable (most hide the cable routing in the vehicle used most) and swap it to different vehicles any time. It can also display four guages at once. The website is more detailed but here are a few examples:

MPG
miles per tank
RPM
engine temp
fuel pressure (on some vehicles)
Inlet air temperature
MPH
engine load
engine timing
total Miles driven
miles driven that day
miles to empty
average trip cost and a host of other stuff.

Basically this guage will show if tow or cruise mode or 55 vs. 65 is more efficient. Very impressive computer for about $130. You used to only be able to buy them from the website. I saw them in Auto Zone the other day.

Do a search on U-Tube and you can see them demonstrated. I am satisfied with mine.
 
A simple gas saving trick I use when towing and sometimes when I'm not, is to pull in behind a big semi and let him break the wind for me.

Works best on the flat sections of I-5 through the Sacramento and San Joaquin Valleys.

You get better savings the closer you follow, but it can be dangerous, obviously. On the other hand, you can't stop too quickly with the boat behind you, but the semi can't either, probably.

Don't try this with a grossly over loaded tow vehicle. Would be best with a 3/4 or 1 ton truck.

Some truck drivers are required to drive 55 instead of allowed to cruise at 70, and you can get the best increase in mileage at 55, if you can stand to go that slow.

Also, it kind of ruins the view of the glorious landscapes of the drive, but who cares when driving down the likes of the part of California mentioned above?

Joe. :teeth :thup
 
Sea Wolf":1ql8dzpu said:
A simple gas saving trick I use when towing and sometimes when I'm not, is to pull in behind a big semi and let him break the wind for me.

Joe. :teeth :thup
Click to expand...



That is one of the most dangerous and annoying things you could possibly do. I've driven over 3.5 million miles. I never permitted anyone to pull a stunt like that unless they were in radio contact with me and a few underlying conditions.
 
Casey

I have a Super Duty F250 with the V-10 engine. I put a cover over the bed. I consistently get just over 15MPG at 65-70MPH not towing. I get just under 12MPG towing my little Alumaweld that weighs about 2500# on the trailer with gas and gear. I haven't towed Cocoon enough to get a towing mileage figure, because I keep her in a marina.
 
Myth Busters tried the truck drafting and found for it to have any real benefit you had to be extremely close. Then again, they also did the Knight Rider trick of driving up a ramp into a moving trailer and it worked, so maybe that's the answer.

Besides, B~C is famous for breaking wind while driving and he still gets average economy.
 
TyBoo":3fepsfp1 said:
Myth Busters tried the truck drafting and found for it to have any real benefit you had to be extremely close. Then again, they also did the Knight Rider trick of driving up a ramp into a moving trailer and it worked, so maybe that's the answer.

Besides, B~C is famous for breaking wind while driving and he still gets average economy.
Click to expand...

And you don't want to be close behind him. :shock:
 
I brought my C-Dory from Oregon to Arizona via I-5 and I-10. The tow vehicle is my 3/4 Chevy 2500HD pickup. It has a built in mileage indicator and a button your supposed to push when you are towing something. Throughout the trip I set and used the cruise control at 55mph. I stayed in the right hand lane and had a relaxed trip. Traffic flowed smoothly around me and I had lots of clear road ahead of me most of the time. My gas mileage was a consistent 14.9 per gallon. Of course I disengage the cruise control on rough hill, heavy traffic, and curvy roads...I just turn up the tunes and hum on down the road.
I like the idea of covering the back of the pickup to reduce drag. I think I will try that...as for the price of gas...before I retired I figured out my monthly budget and I factored in $5.00 a gallon gas. Now I hang out at home until I have enough money saved for my next trip.
Amanda
 
Having towed 1900 miles each way to Prince Rupert several times by now, I'm often tempted to keep the rig moving at 65mph or better, but I know it's going to make a big difference in fuel consumption. When I'm more patient, enjoying the scenery more, and rolling along at 55 or so, I get almost 11mpg. When I'm less patient at 65 or more, I get 9.5-10mpg. This with a Dodge/Cummins pickup, with a hard tonneau cover.

All this assuming little headwind, which makes a huge difference with our big tall non-aerodynamic boat. Headwind can drop mileage by 1 or even 2 mpg.

Towing our also non-aerodynamic travel trailer, similar speed differences can change mileage from 14.5-15 down to 13.

Seems to me that once your tow vehicle is decided, and all is set up properly, the significant variables are speed and headwind. Air resistance is far more inportant in the long haul than weight.

But along with speed, there's how determined you are to maintain that speed. You can burn a lot of extra fuel by insisting on maintaining your cruising speed uphill, rather than letting the engine ease off a bit and climb hills slower. Cruise control is not your friend when towing in hilly country, or in my experience even on relatively gentle slopes. If I watch the gauges and listen, it's clear that cruise control sucks a lot more fuel with little time saved when going uphill.

As truckers say, develop an educated foot. Drive as if there were an eggshell between your foot and the pedal.
 
On our trip to Lake Powell last fall, pulling the Tom Cat, as an experiment, I drove down at 55 and came back at 60-65. I was really frustrated because I would reset my GMC's gas mileage readout at every fillup and the results were very inconsistent. There were days when a headwind was very apparent, with obvious mileage effects, and other days on level ground where it would vary by 3 mpg. The truck is a 2500HD Duramax.

I'm tempted to get that scan gauge mentioned earlier.

Warren
 
towing is all about weight, breaking wind helps lighten the load :) If we're towing very far I always try to have the boat fuel tanks empty & fill up when we get where we're going. Having a single axle trailer also helps helps with fewer flexing tire sidewalls, there's a reason you see more big rigs running super single tires instead of duals. The real gas saving tip I've run across is to just hop a plane and drive somebody elses boat with their gas :)

That scan tool would be a handy addition to our truck, might have to check that thing out.

The new f150 with the v6 ecoboost engine sounds interesting. It sounds like a rig that would get good mileage empty but probably dismal towing mileage.

Just yesterday M had pulled out our fuel log from our Powell trip & we where discussing the costs. Even if fuel goes up a couple of more $$, for us, Powell is still a quality vacation for a reasonable price
 
I've heard that one of the best techniques for saving gas is to drive as if you have no brakes. Among other things this means letting off the gas well in advance of having to stop and not following other vehicles too closely.

Just my 2 cents.
 
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