Better mileage with canoe on top of car?

I just picked up a canoe and mounted it on a thule rack on a pontiac vibe. Driving 180 miles I got about 3 mpg better mileage than I usually get without a canoe on top. Has anyone else seen mileage improvements like this?

The more boats I have and haul around the better my gas mileage!

But sadly, I think my wife is finally starting to question that assertion.

Nope. Never.

– Last Updated: May-06-08 3:42 PM EST –

However, on a one-way drive like that, a good stiff wind in the proper direction could have had that effect. I noticed on my return trip from this weekend's canoe trip with a good stiff tail wind, my car required noticeably less gas-pedal depression than normal, the overall "road noise" was just a fraction of what it usually is, and the car would go up hills without unlocking the torque converter (the transmission's first step in providing extra torque (the 2nd step, if needed, is downshifting out of overdrive)), which normally it would not have been able to do, even without the canoe on top. I can't verify how much the wind helped my mileage on that trip, because on the trip TO the river on the same tank of gas, I was fighting an even stronger headwind.

Having a canoe on top COULD increase your fuel economy IF you have a good strong tailwind AND you drive at a slower speed than the wind is blowing (which no one would ever do unless the wind were really fierce).

it is possible that
driving your car those 180 miles could have involved less starts and stops than you typically do. It is the constant red lights, braking, and stop signs that really kill gas mileage. If you did those 180 miles on a highway or roads with less stopping/starting than you normally do then you could see an improvement in gas mileage. However, this would be due to less stops/starts and driving at a constant speed than to having a canoe on top, which always creates extra drag. I typically see better gas mileage when my boat is on top, but that is due to driving a longer distance on roads with little or no stop/start driving. My normal driving is all start/stop in the city.

Yes, on my F150, over many trips I
got a mile or 2 better with boats on it.

That makes the most sense yet.
I get about 4-6 mpg better on straight highway versus city/highway/traffic mixed. Likely, that was his difference, and the canoe was coincidental, and not enough negative influence to overcome the benefit of highway speed.


Too many variables
You would need to drive the exact same route without the canoe, in the same type of wind and traffic conditions, to know if the canoe might actually improve the airflow over your car.

I suppose it is possible, but usually when someone rooftops their boat(s) the mileage drops, often quite a lot.

driving wrong vehicles ?
I typically see a 2 mpg reduction w/ my canoe on racks, 3+ mpg loss w/ 2 canoes up

There are very few situations
where increasing your cross section or adding weight to your vehicle can improve your mileage.

If this were a real effect, people would be putting canoes on all their vehicles these days!

Driving a constant speed between 45 and 65 will almost always give you much better mileage than stop and go stuff. Your miles per gallon at the red light is zero (if your engine is running). That is one of the primary benefits of hybrids – they shut down the engine when stopped.


Must have been down hill…

– Last Updated: May-07-08 5:49 AM EST –

both directions, with the wind at your back !

I think I'll try three canoes next time instead of two


Most likely
The most probable is that my fuel mileage increased because I accelerated and slowed down much more smoothly. I guess I need to change my driving style.

that happened to me
when my other car came down with a problem, right before our vacation, we decided to strap the 17’ grumman barge on the top of our volkswagon beetle. our gas milage actually did increase a little. this was back around 1980 so i can’t produce the exact numbers but we were both quite surprised.

Nope, but …
Never got better mpg with canoe on top, but never got worse mpg either. I have a 1999 Subaru Forester with 190,000 miles on it. I always get about 23 mpg no matter what: boats no boats, racks no racks, loaded with boats or just me. The only time I get worse mpg is with two canoes on top and head or side winds. The only time I get better mpg is when I drive slower on the highways.

It must also be HP and gearing
related. The pick-ups I’ve owned pretty much got the same mileage regardless of conditions.A full sized truck is going to feel the impact of a couple of boats a whole lot less than a 4 banger.

Lower MPG w/canoe.
We always get lower mpg with the canoe on top. More wind = even less mpg. If you are getting better mpg it is most likely as said that you are driving your vehicle with a “softer” approach. I never whip around the corners like I usually do with a canoe on the roof. They say it’s a good idea to drive everyday like you had a glass of water sitting on your dash.


but I have to be paddling really hard.

Aerodynamics contributes about
70% of your cars resistance to movement or total perceived friction. The rest is from engine friction, tranny friction, tire rolling resistance, and wheel bearing friction.

A canoe, on certain vehicles, may actually enhance the aerodynamics due to filling in open areas that usually would create drag. A pickup truck with a level canoe riding close to the roof would be most likely to show a benefit like this.

I am uncertain of your vehicle profile, but despite what we see, the wind often reacts differently than we might predict. The weight of the canoe is less than a person, so no significant effect from the weight given the total weight of you and car and boat. The aerodynamics is the key to mileage.

Most vehicles will have a worse aero effect with the canoe on top, but not all.

AMC Eagle gets better mileage w/
I drive an 85 AMC that gets better mileage with a canoe. I have driven it locally and on the highway with and without the canoe. In both types of driving it gets better mileage with one canoe. Locally with 1 canoe, I get 1-2 mpg better. On the highway, I get 4-6 mpg better than I would on the highway without a canoe.

Generally, when I add a second canoe, the mileage drops 4 mpg.

Racks are culprits
I had a mid-90’s Intrepid, a very aerodynamic design that got good mileage for a full sized, well powered car (in the mid to high twenties). Yakima racks killed the mileage on this car, cut it about 4mpg. Put a canoe on those racks, and the mileage would bump back up to near normal. The canoe didn’t really improve on the Intrepid’s aerodynamics, but it prevented the turbulence caused by the racks, and improved the vehicles the mileage of the vehicle in racked configuration.

Only one boat gave me better mileage
It was a 13.5 Perception America. I always got a mile or two more a gallon when I carried it. No other boat gives me more MPG but it’s still about the same.