Trailers vs racks - fuel economy

I am in the process of building a trailer to haul canoes. The main reason is for when I have to carry more than two, I expect a trailer will be far easier and safer than putting them on my roof. I also believe that it may be more efficient with respect to fuel use, as the canoes will travel in the draft of the car, rather than creating resistance on top. On the flipside, the trailer itself weighs considerably more than just the racks, so I expect it would burn more fuel accelerating.

Does anyone have experience with trailers versus roof racks and their relative efficiency. Will my car have an easier time pulling two canoes than carrying them?

Thanks for any opinions and observations.

I Dunno
The downside to a trailer is parking. Last summer I remember the boat ramps we used being packed with autos with trailers and finding a space for just a car being easy.

If you have a Pinto or a small car there may be some drag but my tuck with a V8 wouldn’t even notice a kayak trailer.

As for the racks, they have to create drag but at least something hydro dynamic should be aerodynamic too, I think.

How is your back and how tall are you? Are you adept at pulling a trailer?

I’d like to have both myself so I could do my day trip with just the racks and do group events with a trailer. The others could chip in a few bucks for gas and any fuel economy off set.

Now when I had my BMW, I rarely used a trailer, that’s for Harleys :slight_smile:

Trailer much better at freeway speeds
I built a small kayak/canoe trailer from a small boat trailer I got from Academy Sports. With 2 kayaks on racks on my wife’s Chevy Cobalt you could really feel the drag on the interstate. But with the trailer, you hardly know it’s back there. Plus it’s a lot lower load height and you can keep an eye on them in your mirror.

Devil may be in the details
I can’t answer for your car and canoes etc., but I have found that trailering 1 or 2 kayaks on our modified snowmobile trailer has little effect on mpg. I’ve been pulling it regularly since spring of 2002. Tow vehicles have all been trucks or SUVs with 6cyl or 8cyl engines. What mileage variation occurs is impossible to attribute to the trailer, because the wind here can cause variations of 1 to 2 mpg. In other words, the effect of the trailer is too little to notice, by comparison.

I have only rooftopped a low-profile SOT (not sea kayaks) on my truck so can’t compare apples to apples re: my trailering. However, with my husband’s Tahoe, rooftopping 2 sea kayaks costs us about 2 mpg vs. trailering with it, which has no effect on mpg.

The main obstacle to trailering is, as someone else mentioned, parking. I greatly prefer trailering for most situations, but I’m not wild about it for road trips. I don’t know what we’re going to get for space at motels or campsites.

If you can have a choice (both trailer and rooftop), that’s best. Loading/unloading the trailer is much easier and safer, and when the wind is tossing boats around on the ground you will REALLY appreciate having one.

Weight factor is compounded when
being lifted. By that, I mean that the weight

effect of pulling a ton on flat terrain is minimal,

but if you are pulling a ton up a mountain or hill,

then the weight work factor is a compounded factor.

I’d go with the trailer, as long as no mountains

are being crossed often.

Assuming the boats are properly
secured with either trailer or roof top carry, why would a trailer be safer? Its extra weight, extra tires that could blow out, and a connection that may not be as good as you may think. I see a lot of trailers of all sorts on the side of the road in my area broken down. Of course, lots depends on how well built the trailer may be. Many of the trailers I see carrying kayaks are not that great.

Be sure to get a good tongue lock for that trailer and, if possible, secure it with heavy chain or cable to something fixed.

My trailer has negligible effect
on the truck. The racks with boats have some effect.

There is alot to consider. You think waay ahead with a trailer, about left turns, motel parking, restaurant parking etc. Its quite easy to forget you have it and park in the angled parking for cars at interstate rest areas…embarassing. You have to be ready to deal with flat tires, malfunctioning lights (they are temperamental) and possibly having a trailer wheel go over off the road and cause everything to roll over.

Plus you always have to be aware that you have one behind you and not cut off people. And its scary with trucks at night.

Pick a good trailer with good sized wheels (mine are 16 inch) and a decent design that doesnt sway.

I rooftop for one or two boats and the trailer gets pulled out for three or more. Usually this is once a year for about four thousand miles.

Tolls are higher…
sometimes much higher with three axles… at least in Florida.

used both
over the past 30 years. Each has it’s advantages depending on the roads and how far off road you plan on going. I’ve found that for the long haul the trailer is the way to go, but if you are traversing back in to remote waters, my Tacoma with roof rack gets the job done nicely. Gas mileage pulling the trailer is almost the same as no trailer at all.

If you do use a trailer, keep things low, solidly fastened, and well marked. (lights, flagging, etc.) The trailer is also much easier to load if physical limitations are a problem. Just my experience…

racks suck gas
I have no experience with trailers, but 2 canoes on my rack makes my Dakota go from 18 mpg down to 12. For road trips of any duration, I end up with one canoe on the rack, one in the bed, and am back to close to 18. Something about that air dam formed by the second canoe…

make sure your engine can handle it
We had a modified heavy steel trailer we used years ago for hauling four kayaks with a 4 cylinder Toyota van. While we didn’t exceed the vans suggested towing limitations we did however end up having to put a new transmission in well before they are known to be a problem. For short hauls I’m told about any car will be ok but for longer hauls (we were going 400 miles roundtrip every three weeks) and highway speeds with hills you should have a truck set up with the extra cooling systems for towing. Sounds like you have no choice if you are carrying more than two canoes but make sure you have spare trailer wheels, light plugs, bulbs and the like since they seem to fail at the worst times! I never did learn to back up the trailer very well and that was annoying but my husband could micro park the darn thing every time.

This is weird , but my Tacoma’s
mileage from SC to Fla and back @ 75mph was 17 mpg with a canoe and kayak on the roof. It normally gets 15 no matter where or how I drive. I had the same experience in my old F150.Apparently, the boats help the aerodynamics.

I drive a AWD GMC Safari van (poor milage to begin with.) 78" Racks alone cost me 10%, and a pair of canoes cost another 10% in MPG. When I put 3 canoes on top, 8 people in the van and a 14 canoe trailer on the hitch I get about 8 MPG, and I worry every mile.

Wind resistance
Carrying 2 kayaks on my Subaru will lower my road mileage 2-4 mpg depending on speed. Local short trips dont make a difference. I have been considering a light weight trailer and believe it would be more economical. Are there speed restrictions in your state? CA limits towing speed to 55mph. AZ does not restrict speed. When I tow my 5th wheel with the truck, I believe the kayaks on the truck rack actually help. I have to stack them over the cab so they dont interfere with the trailer and they act like an air foil in front of the trailer.

Thank you all for your input. I will try to be more specific and answer your questions/concerns.

I have pulled trailers quite a bit. I have driven small buses, horse trailers, and vans with kayak trailers. I have no trouble backing them up when necessary, and have become pretty good at avoiding that circumstance.

My car has a 2.5 liter (151ci) 4 cylinder engine which generates 110 horsepower and 135lb.ft of torque. It has a 3 speed automatic transmission.

I am strong enough to have no trouble getting the canoes on this roof, so this is not an issue.

When I mentioned safety, I was saying a trailer will be more secure than three canoes on a Yakima roof rack that is rated for 165lbs.

I notice a real difference between one canoe and two. Two canoes seem to really increase the drag.

I once drove to Florida with two canoes on an F-150 (302), and the mileage went from about 20 to about 12-14. I suspect a trailer would have helped that rig some, but don’t know for sure.

Again, thanks for the suggestions. I am mostly interested in efficiency on the highway, and will be going slower (around 55-60mph) to try to achieve this. I know my car can haul 2 canoes on the roof comfortably, and am interested in knowing if the trailer will be more or less efficient.

When I have spent some time with each, I will report the results.

4 vs 6 vs 8 Cylinders
I am the last one to ask about trailers, but I can comment on Hp and Cylinders.

I currently have a Nissan Frontier with a large 6 cylinder engine. I get 19-20 mpg and it does not seem to matter too much whether I am loaded or empty. My drop seems to come when I go much above 65mph.

Now, with that being said, my last vehicle was Ford Focus Wagon (loved that car) that had a 4 cyl hamster wheel in it. Empty and driving conservatively, i got 30-32 mpg. When I put a couple boats on top and loaded the camping gear and took on a passenger, I saw the mpg go down to about 18-20 mpg.

So, I think the smaller HP engines take the biggest hit when they take on a load.

My $.02

Good Luck


That probably has more to do with the
size of the vehicle than the HP.

Larger vehicles generally have more HP, and a kayak on a large SUV adds much less area, percentage-wise, than the same boat on a little 4 cylinder car.

There is also a lot of variability in the aerodynamics of trucks, so it is probably not very predictable unless you have access to a large wind tunnel.

Comparing the hydrodynamics of a boat designed to do 4 mph through the water to the conditions on a rack or trailer moving at 60+ mph is questionable at best. They aren’t like carrying a large brick, but some canoes and very open kayaks may not be too much better aerodynamically.

You should probably pick one or the other based on convenience and your ability to load and unload.


myth busters
did an episode about tailgating. Basically, they looked at fuel savings as a function of tailgating distance. From wind tunnel experiments they found out, that the closer you tailgate, the better fuel savings. Basically, there is a bubble of turbulent air flow just behind the leading vehicle. If your car is sitting just inside of it, you will experience lesser wind resistance.

So, on top of a car, the kayaks will experience the whole v^2areac force, sitting on a trailer - just a fraction of it. Of course, one would have to account for rolling resistance.

Too many factors
to say as every vehicle and trailer is different. Most vehicles have a significant downdraft at the rear which applies a good deal of (costly) resistance to a trailer.

My truck (a Yukon) has a large downdraft at the rear of the vehicle that impacts a trailer directly. At 60-70mph a couple of sleek sea kayaks with cockpit covers on a lightweight trailer costs me about 4mpg. When I put a gear storage box on the trailer (2’x2’x4’ rectangular) it costed about 8 mpg. Two sea kayaks on the roof costs about 6 mpg at the similiar speeds.

Safer for two reasons:
Bodily safety and car/truck’s safety, because a trailer is easier to load and unload. The only thing that gets damaged if dropped is the boat itself (if that). Not your back, not your rooftop.