Towing speeds and fuel economy. Scamp 13.

[SailorSteve]

Hello all. I've been towing various campers for years and am now moving to a Scamp 13. Will be towing with our 2012 Toyota Sienna 3.5L V6 minivan with towing package. I've got a few questions and would like to see what the other forum members think.

Fuel economy while towing is a function several things: trailer weight, trailer shape, tow vehicle engine/transmission, and towing speed. I'll ignore wind conditions and topography for the moment. For me, it's always been a balance of choosing the right speed. As we all know, the aerodynamic drag goes up with the square of the speed, so double your speed and the drag goes up FOUR times. Therefore the slower you drive, the better your fuel economy should be (and the longer your tow vehicle should last).

The challenge is that if you're going long distances on the interstate, the slow speed makes the trip longer. (duh) The other challenges is that the slower the engine speed the more frequently it has to downshift for even a slight grade. So, at what speed do you all tow your 13' Scamps and similar size campers? Would be interested to hear your speeds and fuel economy, particularly if you tow with a Toyota Sienna or similar minivan with 3.5L size engines. THANKS IN ADVANCE.

(Side note. The reason I ask the question is because I towed a small UHaul moving trailer to Charleston last week using the Toyota. It was the second from the smallest single axle tailer. I'm guessing total weight at 1,000 pounds. I towed at 68-72 MPH and my fuel economy dropped from my normal 24.5 to 14.2 (a 42% drop). I was a little shocked but probably should not have been. There was plenty of power and the transmission was mostly in 5th, sometimes 6th gear @ about 2,200 to 2,600 RPM. I know some of the poor economy was my speed, but also suspect that it was the square shape of the trailer combined with a square minivan rear end. Huge vacuum and turbulence in between. Just an FYI.)

Regards, Steve

[mcbrew]

Oh, boy... You're going to get a lot of responses to this.

First, let me say that most 13 foot campers are going to have tires that are rated for a top speed of 65 MPH. I generally don't exceed this. Usually I drive between 60 and 65 on the highway with the Scamp in tow. I have towed the Scamp with me previous car, a Scion xD with a 128 horsepower 1.8 liter engine, and my current car, a Subaru Outback with a 170 horsepower 2.5 liter engine and a CVT transmission. With the Scion, I usually got about 23-24 MPG towing. With the Outback, I usually get 22-23 MPG towing.

I don't believe that towing speed is going to have a significant impact on the longevity of the tow vehicle, unless it is overheating. I towed for a LOT of miles with my previous car, and it has over 600,000 miles on the original engine, and is still a daily driver (although not owned by me since I sold it in 2002). That car had 120 horsepower and had a class 3 hitch installed. I towed many other cars and light pickups on a tow dolly, as well as Uhaul trailers and a large popup camper.

Now, if you had a 40% drop in fuel economy with a 1,000 pound Uhaul trailer, I suspect that the high speeds were to blame. We towed a small Uhaul many times with the xD (up to about 1,600 pounds) and it returned 28 to 32 MPG doing so. This was the smallest Uhaul enclosed trailer... 4x8 feet, I believe. Here's a pic, just for fun:

[Tom Trostel]

I've towed 2 trailers with 2 Toyota Siennas. Our first combo was a 1973 Compact Jr. towed with a 3.0 L 2003 Sienna. We replaced the 2003 Sienna with a 2006 3.3 L which towed the Compact until another trailer was bought. Our current combo is a 1980 Bigfoot 15B17G towed with the 2006 Sienna. The Compact Jr is 6 feet wide and 5.5 feet tall and weighs 1400 lbs. The Bigfoot is 8 feet wide and 7 feet tall and weighs 2600 lbs. Both trailers are rather square and boxy. I tow at 60 mph to try to get the best fuel mileage. When not towing, the 2003 Toyota got 20 mpg in town and 25 mph (at 70 mph) on the highway. When towing the Compact Jr. the 2003 got 14 mpg. The 2006 Toyota gets 19 mpg in town and 24 mpg on the highway (at 70 mph) when not towing. The 2006 Toyota got 14 mpg when towing the Compact Jr. and gets 12 mpg when towing the Bigfoot. Of course head wind, terrain, and 10% ethanol gasoline all alter the numbers.

Compact :: California redwoods picture by tomNjo - Photobucket

http://s293.photobucket.com/albums/m...t=IMG_1068.jpg

[Daniel A.]

I would consider a 25% fuel drop towing to be expected.
It is very hard to deal with actual hard numbers and might be better to look at things in percentage.

[Lynners]

Hi! Steve,
Here is a comparison for you.
Our tow vehicle is a 2001 Toyota Sienna 3.0 V6 engine 200 Hp. This summer we travelled from Alberta, thru Idaho, Washington State into B.C and back home to Alberta (1800 miles) towing a 13ft. Trillium. Lots of mountain driving. We tried to keep speed to 60 mph, averaging 20 mpg. ( those are Cnd. mpg. you'll have to do the math!) Lynne

[Nancy]

Steve,

We use a Honda Odyssey, generation before current one.

Our Scamp will be lighter than yours, no air conditioner, water, or refrigerator.

On our 3-4,000 mile trips we always average 17 1/2 mpg for the entire trip. Our last long trip was much better because somehow we missed headwinds both out and back.

However, we would never drive the speed you mentioned. 60 mph for us on major roads. On many secondary scenic (twisty, curvy, hilly) roads we drive slower yet. I don't think we are a good comparison for you.

Nancy

[Rene]

I agree with the OP premise that towing speed and fuel economy are linked. On my last trip we traveled at 55-60 mph and averaged 15 mpg. On one stretch I traveled at 50 mph and got much better fuel economy but it was fairly flat terrain overall even through a mountain pass but traffic was light and I could just toodle along. The faster you go the worse your fuel economy gets. We have a 4.3L V6 in a shortbox 1/2 ton full size Chev. Highway driving while not towing gives us 25mpg. I think besides speed another factor that contributes to fuel economy is how much of your vehicles towing capacity are you using? We use pretty much all our towing capacity as factory rated towing our boler 17. I have a theory that if you only use 1/4 or half of your towing capacity you should get better fuel economy than if you max it out with a big load.

[MC1]

Originally Posted by SailorSteve

Hello all. I've been towing various campers for years and am now moving to a Scamp 13. Will be towing with our 2012 Toyota Sienna 3.5L V6 minivan with towing package. I've got a few questions and would like to see what the other forum members think.

I'm guessing total weight at 1,000 pounds. I towed at 68-72 MPH and my fuel economy dropped from my normal 24.5 to 14.2 (a 42% drop). I was a little shocked but probably should not have been. There was plenty of power and the transmission was mostly in 5th, sometimes 6th gear @ about 2,200 to 2,600 RPM. I know some of the poor economy was my speed, but also suspect that it was the square shape of the trailer combined with a square minivan rear end. Huge vacuum and turbulence in between. Just an FYI.)

Regards, Steve

Steve, my on line pal tows good sized Airstream with his 3.5 V6 Sienna and he posted this yesterday on the Airstream forum....

//// "Towing a 2011 28' International with our 3.5 litre V6 Toyota Sienna, we averaged over the 2012 camping season 12.8mpg (US). Most terrain was pretty flat and we tend to do around 60-65mph. Our best ever was 14.9 on flat terrain with no headwind doing around 50mph. Our worst was 10.1 on a wet and windy day on our way back from the Finger Lakes in NY.
Our real advantage is the average 28.4mpg when not towing :~)//// "


Based of the comparision it appears speed and aerodynamics are the factors that affect mileage, with trailer weight being a small factor.

Note his combo is a pro set up.

[SailorSteve]

Wow. Thanks, everyone, for the speedy replies. This is exactly the kind of feedback I was looking for. Towing speed is definately the primary culprit when it comes to fuel economy. I'm a pretty analystical guy, so I'll be keeping records and will post results in the future. If I can stick to 65mph and get 15-17mpg, I will be very happy.

FYI... My old rig was an Aerolite Cub 236 (nice but fell apart in 10 years !!) that weighed 4,500 lbs. wet. Tow vehicle as a Ford E150 van with 4.6L V8. Normal mileage is consistenly 16-18mpg. Towing at 58-62mph yielded about 9mpg. That doesn't work in today's economy, hence the move to the higher quality (!!) and lighter Scamp 13.

[MC1]

Originally Posted by SailorSteve

Wow. Thanks, everyone, for the speedy replies. This is exactly the kind of feedback I was looking for. Towing speed is definately the primary culprit when it comes to fuel economy. I'm a pretty analystical guy, so I'll be keeping records and will post results in the future. If I can stick to 65mph and get 15-17mpg, I will be very happy.

FYI... My old rig was an Aerolite Cub 236 (nice but fell apart in 10 years !!) that weighed 4,500 lbs. wet. Tow vehicle as a Ford E150 van with 4.6L V8. Normal mileage is consistenly 16-18mpg. Towing at 58-62mph yielded about 9mpg. That doesn't work in today's economy, hence the move to the higher quality (!!) and lighter Scamp 13.

More good feedback, thnxs Steve. Note our 4,500lb wet 23' Airstream towed by a 3.0V6 Nissan Minivan averaged out to 13.5/14MPG US. 25MPG solo for the Mvan.

Note we averaged 17MPG US towing the 2,000lb wet Coleman (low profile) PU with the same van.



An educated guess would suggest the same Nissan Van would get about 16 MPG US towing a wet, 2,000lb egg.????

Your Sienna with a much bigger, more powerful engine should be more fuel efficient towing an egg, one would think.

[melissab]

We have a 2006 Toyota Sienna towing a 2012 Scamp Deluxe with A/C. I drive 55-60 mph. Average fuel economy is 15 mpg over lots of different terrain. Best was 16.5 mpg totally flat (FL) driving 55 mph. Normally I average 19 in the city (ALL city with lots of lights) and 24 on the highway at 70 mph. Where it's flat I stay in 5th gear but through hilly terrain I drop to 4th to avoid the transmission hunting.

[Byron Kinnaman]

Ok, Here's my take on mileage and towing speed. Well, I don't worry about mileage, but towing speed that's a different matter. There's lots of reasons to hold towing speed in the near 60mph range or lower.
First and the most important in IMHO is I'm in no hurry. I'm towing my Scamp to see the world, and it's much easier to see when going slower. Even if it's a road I've been over several hundred times, things change so there's something new to see.
Second, actually relates to first in a way. Safety, I want to be able to continue to slow down and "smell the roses". Speed is a factor in many many accidents and with a trailer the speed of safe control drops considerably.
Tires, of course, wear and tear on the trailer and the tow all come into play. That said I think the biggest thing that governs towing speed is attitude.

[honda03842]

Though we tow a Scamp 16 and not a Scamp 13, they have very similar frontal area and shape. I expect that there's only a significant mpg towing difference in hilly country.

We get about 80% of Interstate mileage when towing.

On the Interstate we get 28-30 mpg driving about 65 mph with our 2004 Honda CRV. When towing we normally get 22-23 mpg when towing our 1991 Scamp 16.

When driving into a strong head wind we have dropped to 18-19 mpg. Driving 55 mph into a 20 mph head wind is like driving 75 mph.

I think head winds have the biggest effect on mileage and hills are secondary, though hills stress the tow vehicle on the way up, you get mileage back on the way down.

With a manual transmission I become the 'hunt and peck' aspect of the transmission. Since we've added an Ultragauge I can now see engine load and instantaneous miles per gallon. Since adding this I generally drive in 4th and less rarely in 5th. On some long, steep mountain passes I down shift to 3rd.

One of the positive aspects of our manual transmission is that I can put the transmission in 'roll' easily any time. Frequently surpassing 200 mpg on the way down with out exceeding speed limits.

We've just began our trip north and east to the Scamp Factory. We generally avoid Interstates and love roads like route 93 through Idaho and Montana. We drove about 60 mph on this virtually no traffic, north south, cross country, road.

We love this class of roads because the ride is more interesting, the lack of traffic less stressful. Whether you drive 55 or 65, when you take into account stoppage time, the difference is hardly significant in road time. Particularly for us where we, like Byron in the previous post, take our time and enjoy the journey.

We like many on this post never drive over the tire's rating of 65 mph.

[SailorSteve]

Thanks for the input. I agree with Byron, Norm and Ginny. Slow down and enjoy. It's a balance but I'm definitely on the page of being safe. While going too fast creates the opportunity for an accident, so does going too slow relative to the rest of traffic. I don't like to be more than about 10 MPH less than traffic, unless I'm on a steep hill with a truck lane.

Hey, that reminds me. How well do those ScanGages work? I'd love to know what my transmission temp is without having to install a gauge in one of the lines.

[Byron Kinnaman]

Originally Posted by SailorSteve

Thanks for the input. I agree with Byron, Norm and Ginny. Slow down and enjoy. It's a balance but I'm definitely on the page of being safe. While going too fast creates the opportunity for an accident, so does going too slow relative to the rest of traffic. I don't like to be more than about 10 MPH less than traffic, unless I'm on a steep hill with a truck lane.

Hey, that reminds me. How well do those ScanGages work? I'd love to know what my transmission temp is without having to install a gauge in one of the lines.

Interesting phenomenon in at my observation. Driving too slow when towing doesn't seem to be much of a problem. It appears to be much less of a problem when than when not towing. On freeways it's easy enough for traffic to go around you. On 2 lane roads I try to pull over and let traffic go by or slow down in passing areas to make it easier for traffic to pass. Most drivers don't get as impatient with travel trailer being towed as they do with other slow downs. I often get a friendly wave and a smile when I make a move to let them pass.
I've noticed this in most of the western states.

Also of note that in some states the towing speed is much lower than the non-towing speed. Example CA, 70 mph for passenger cars and 55 mph towing. Oregon the 65 mph, 55 mph. Washington 70 mph, 60 mph.

[Thomas G.]

Originally Posted by SailorSteve

..........
Hey, that reminds me. How well do those ScanGages work? I'd love to know what my transmission temp is without having to install a gauge in one of the lines.

I have a Scan Gage on my Escape hybrid and I love it. It tells you what all the sensors are actually reading, even things like voltage to the battery. It will also find fault codes and allow you to reset. You can move it car to car, so for instance I can check out a code on my wife's car fix it, then move it back to my Escape.

[deryk]

Well Im hopeing wih whatever Scamp I end up with, 13 or 16 I will do a little better on fuel mileage then I did with my lil gypsy vardo I built (more pics on my profile) the overhung roof and flat face killed my gas mileage. 19/23 normally on my v6 Rav4 to like 13mpg towing around 60mph.... one tank with my ac on and doin 70 I averaged 10mpg...bleh(also learned on that trip why when its a 100' outside to not drive so fast.... melted a tire)

Fiberglass RV - deryk's Album: My lil gypsy vardo - Picture

[floyd]

Back in the early seventies, the streets were crawling with cars capable of 150MPH and 10 second 1/4mile times,according to the owners.
Then came the gas crunch and those same cars were suddenly capable of 25MPG! OH MY!

Now I know that generalities are always false, but generally...

Here's what I have observed concerning towing a 13 Scamp.
Without the trailer my interstate speed is just under the flow of traffic (about 75MPH).
With the trailer, my speed is just under 60MPH.
The MPH difference "generally" absorbs most of the MPG difference.

"Generally" I think you should expect to get at least your "in town" non-towing mileage with a 60MPH highway towing speed and light accelleration.(13 Scamp).

[Borden]

Well lets start by saying I live in Canada; that said will convert 4 L per Gal instead of 4.5 L per Gal and km to miles hope I am close for our cousins in the south. At 4.5 L the car gets 49 mpg but in US gal 4 L it is only 40.5

We never go over 92 kpm or 57 mph and tow as light as possible

The normal range is 80 to 92 kpm or 50 to 57 on the highway

Mileage is 7.5 L per 100 km to 8.2 L per 100 Km or about 28 to 32 mpg US average have seen lower and higher depends on wind and average road grade; too windy and we would just pull over although so far not needed.

Shifter has a hill setting forget to go out of it at the top and mileage drops, have done that.

Car gets 5.7 L to 100 Km or 40.5 mpg US gal according to the dealer but they exaggerate that would be down hill in neutral I think

[deryk]

"light acceleration" is another of my problems lol ....lead foot lol