MPG towing RTT trailer. Results

[RoyB]

Yesterday I took my new built RTT camping trailer on its first long trip. 50 miles each way. All highway.

The tow vehicle is a 2010 Toyota Venza V6 / 265HP.

Non towing I get 25 mpg ave, day in, day out...cruising highway at 70mph.

With the trailer I got 17 mpg for the entire 100 mile round trip.

I was surprised as the trailer weighs only 1300 pounds for this test and it is lower than the roofline of the Toyota thereby offering minimal wind resistance.

What are folks getting for MP{G towing comperable trailers with Subaru Outback, 4Runners, Xterras??? These are the three vehicles I'm thinking about getting in the future.

 

[RoarinRow]

Nice trailer though. But wow that's a big mpg difference to me.

 

[Billiebob]

Thats pretty typical for anything once you start towing. All todays vehicles are setup to deliver fantastic mileage as empty commuters..... Even F150s. My TJR can do 22mpg but gets 18mpg with my Square Trailer if I drive 55. I almost bought an F150 for the great milage rating but then I talked to guys towing and there was no advantage once a trailer was coupled up.

To get an accurate mileage reading, you need to average a few tanks of gas. Far too many anomalies in just a 100 mile run.

 

[RoyB]

The Toyota handled it fine. No constant shifting and hills were no issue. I teally had to keep looking in the mirror to be sure it was there!

In my 2018 6.4L RAM Hemi pick up, I get 17mpg non towing and 10mpg towing a 20', 7000 pound toy hauler. Nearly the same ratio. (Need to do a test with the RTT trailer)

I'm sure it is all about torque.

Those small, high HP engines have HP but low torque. The 6.7L Hemi has good HP and lots of torque

My 2006 Dodge diesel returned 17mpg non towing and 12 mpg towing this 20'/7000# trailer....A much better ratio.

 

[RoyB]

This 100 mile loop is my test loop that I've tested many vehicles on. The best I have to compare.

On another forum there was a conversation about small gas and diesel engines and the huge difference in MPG between tiowing and non towing. The RAM 3.0 diesel was discussed at getting nearly 30mpg non towing and 17mpg towing. That tells me that engine was working its balls off to tow the 6000# trailer. Using nearly twice the fuel. Saw the same thing with the EcoBoost motors.

 

[jeepers29]

I pull a 1000 lb teardrop with our JKU, and the mpg only drops about 2mpg on average. The teardrop is friendlier to the wind drag though.

 

[RoyB]

Yes, it is all about aerodynamics

 

[Tim N Michele Davis]

On 1000 mile round trip to Arkansas from Alabama our 1995 Landcruiser got 11 mpg and our 2019 4Runner got 15mpg. This is towing our Smittybilt Scout trailer

 

[Anak]

My 2006 Dodge diesel returned 17mpg non towing and 12 mpg towing this 20'/7000# trailer....A much better ratio.

Those are about the same numbers I get with my '95 Cummins.

If you get something that is intended for towing there is not nearly such a drop. OTOH, you pay for it all the time you are driving it. Most folks are probably best served getting good fuel economy most of the time and just paying at the pump for that minority of time they are towing.

 

[smritte]

I get about a 3-5 mpg drop towing my M100 with RTT. Loaded out i'm a little over 1400#. This is on my 96 Cruiser and my 2019 Tacoma. My TJ saw a significantly higher drop (don't remember number). I think even though it had 4.88's to offset the 37's, the motor was struggling with the vehicle as it was.

 

[Pretzel]

I'd love to see a wind tunnel experiment, but I'm betting that nicely streamlined air flow coming off your roof and sides are making all kinds of turbulence (drag) between your tailgate and trailer.
[edit] Nice trailer by the way!

 

[RoyB]

I built an aerodynamic cover for it. Will be testing this week...,.

 

[Road]

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Though it may be all you have to compare, 100 mile run is insufficient to get a real average, especially if depending only on your DIC for the info. I suspect you'll see a bit less drop than 8mpg over a a lot more miles and more accurate avg.

Also, in your example from the other forum, 6,000 lb trailer for a small engine is a hell of a lot different than what you're towing or what most of us tow for adventuring. You'll mislead and frustrate yourself to use apples/oranges examples when considering your own situation.

My trailer is 1250 empty, 3275 GVW. Measured over two long adventures equaling over 34,000 miles of mixed driving, I consistently drop around 4mpg when towing. I usually get around 21 when not towing but van is fully loaded, and drops to 17 when additionally towing my loaded trailer.

A lot has to do, too, at least with my rig, with tire pressure, driving surfaces, and terrain. A lot more highway miles at higher pressure, a lot better mileage. Spend weeks on the beach sands and back country aired down and up and over remote mountain passes results in much less avg in mileage.

Still, averaged over all scenarios combined, I regularly avg a 4mpg difference.

Good luck with the new cover; looks interesting!




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Roaddude - On the Road In North America - ROADDUDE

Roaddude - Traveling Photographer/Writer/Artist On the Road In North America. Gear, reviews, people, places, and culture.

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[Billiebob]

I'd love to see a wind tunnel experiment, but I'm betting that nicely streamlined air flow coming off your roof and sides are making all kinds of turbulence (drag) between your tailgate and trailer.
[edit] Nice trailer by the way!

this ^^^ close coupled makes all the difference.

 

[Billiebob]

Another factor is speed.
At 60mph plus using the 3 lane for passing I get 14mpg towing.
If I stay under 55mph and never pass I get 18mpg towing.
My best not towing is 22mpg on the highway.

The double nickel is maybe the easiest way to get better fuel economy.

 

[RoyB]

But........"I CAN'T DRIVE 55!!!"
Around the Northeast, if you drive 55 you will surely get rear ended or a ticket! I drive 65-68 and NEVER pass another vehicle!
My truck pulling the big trailer is best at 63.....I'm not passing anyone. Just sitting in the middle lane for hours on end, listening to music and loving America!

As far as 100 mile loop not being representative of true MPG. I beg to differ. The MPG I get on this loop with the truck pulling the big trailer is identical to what I get driving from Massachusetts to Phoenix every winter.
My Toyota Venza with 102,000 miles averages exactly the same overall MPG as the loop. I calculate MPG on every long trip I take. And having been a traveling executive, I did lots of long trips in that car.

 

[Pretzel]

One more thing to check, jack it up and rotate the wheels, make sure there isn't any unusual resistance in the spin, maybe have a bearing/lubrication issue. I'm assuming you don't have trailer brakes to check on that thing.

 

[RoyB]

Hubs are fine. After 100 miles at 45 degree weather, hubs were still cold and the tires road surface area was barely warm. No friction there.

I'm totally convinced it is all about wind resistance......We shall see

 

[Billiebob]

Just sitting in the middle lane

That is definitely not overlanding.

 

[RoyB]

That is definitely not overlanding.

I'm not concerned about MPG while overlanding....But ya gotta get there first. Up here in New England the OL opportunities are far a few. I need to travel to PA or VA for anything even approaching OLing. And Nm and AZ are where I spend the winters......