Aluminum Camper Forum

Towing => MPG => Topic started by: rob on July 02, 2015, 08:33:55 PM

Title: How well do you do?
Post by: rob on July 02, 2015, 08:33:55 PM
My TV is a 2.4l, 5 speed (manual), 2009 Pontiac Vibe.  The trailer is a 2015 QS 8.1 with rear deck.

Drove just over 500km (310 miles) to pick it up from the dealer so I decided to check out my mileage.  All driving was done on secondary highways (mostly Ontario Hwy 7).

TV without trailer received 6.6l/100km (35.6 mpg).  On the way back, with dry trailer, 8.2l/100km (28.6 mpg).  A big difference on the way back was my driving style.  I downshifted to slow and help stop.
Title: Re: How well do you do?
Post by: Paul on July 02, 2015, 10:32:33 PM
hi Rob without the trailer i usually get 9-10l/100km (26-23 mpg) but with my 13QBB i get between 18-20l/100km (13-11 mpg) depending if its hilly or not
Title: Re: How well do you do?
Post by: rideandfly on July 02, 2015, 11:21:13 PM
Our TV gets 23 to 25MPG unloaded. Towing the CampLite 11 gets 13 to 14MPG.
Title: Re: How well do you do?
Post by: DavidM on July 03, 2015, 10:10:23 AM
It is interesting, but not surprising. Weight doesn't make that much difference.

My 16TBS probably weighs at least 50% more than an a CL 11 but I get about the same mileage as rideandfly.

But the QS8 with its low profile (and lighter weight still) gets in the upper 20s.

Frontal area makes all of the difference. If you could tow an inflated bounce house and it would get horrible mileage.

David
Title: Re: How well do you do?
Post by: Merlin on July 03, 2015, 11:50:05 AM
I'd love to see a wind tunnel smoke test of a TV+Camplite. I'll bet the turbulence underneath and behind both the TV and the trailer are astounding, to say nothing of the huge wall of air pushed up by the front at speeds over 50mph.
Title: Re: How well do you do?
Post by: J_Westy on July 03, 2015, 12:30:58 PM
Quote from: DavidM on July 03, 2015, 10:10:23 AM
It is interesting, but not surprising. Weight doesn't make that much difference.

My 16TBS probably weighs at least 50% more than an a CL 11 but I get about the same mileage as rideandfly.

But the QS8 with its low profile (and lighter weight still) gets in the upper 20s.

Frontal area makes all of the difference. If you could tow an inflated bounce house and it would get horrible mileage.

David

To get a little nerdy, you can estimate fuel consumption impacts from the following:

Rolling Resistance + (Weight x Hill_Grade) + (Weight x Acceleration) + Wind Drag

Rolling Resistance is basically a constant. Can't do much but use low rolling resistance tires like hybrids and electric cars often use.

Weight*Hill_Grade theoretically cancels out on a round trip since you go up and down hill

Weight*Acceleration is a factor, but you have to accelerate up to the speed you want to drive, so the only thing you can do is keep your weight down.

Wind drag is the big one. It's a function of the coefficient of drag (Cd) and Speed Squared (Speed x Speed). The Cd of a Camplite is much much higher than a Quicksilver. And small changes in speed make a huge difference since it's squared -- for example, the difference in fuel used due to drag when you drive 75 mph versus 50 mph would be 1.5 x 1.5 or 2.25 the fuel needed to overcome drag.

Title: Re: How well do you do?
Post by: DavidM on July 03, 2015, 12:42:26 PM
Quote from: J_Westy on July 03, 2015, 12:30:58 PM
Wind drag is the big one. It's a function of the coefficient of drag (Cd) and Speed Squared (Speed x Speed). The Cd of a Camplite is much much higher than a Quicksilver. And small changes in speed make a huge difference since it's squared -- for example, the difference in fuel used due to drag when you drive 75 mph versus 50 mph would be 1.5 x 1.5 or 2.25 the fuel needed to overcome drag.

Well, not quite right. Wind drag is approximately equal to the frontal area x Cd x speed^2.  The Cd is either empirically derived, ie it is a fudge factor, or it can be calculated using physics that is beyond me. The QS has a relatively low frontal area compared to the CL but I suspect that the CL has a better Cd due to its rounded front although the TV's wind shadow on the QS probably makes the empirical Cd come out about equal.

David
Title: Re: How well do you do?
Post by: rideandfly on July 03, 2015, 01:46:47 PM
Quote from: DavidM on July 03, 2015, 10:10:23 AM
It is interesting, but not surprising. Weight doesn't make that much difference.

My 16TBS probably weighs at least 50% more than an a CL 11 but I get about the same mileage as rideandfly.

But the QS8 with its low profile (and lighter weight still) gets in the upper 20s.


David

Always wondered about buying a larger CampLite by 2' to 5' longer, if MPG decrease much. David answered my question.   My fuel economy is 13 to 14MPG around 60MPH with the 2000lb CampLite 11/Frontier Rig. The Frontier has 261HP 4.0L V6. It's about 1 to 2MPG better with my 2003 Tacoma with 140HP 2.4L 4 cylinder with manual transmission, but that rig suffers performance wise in the mountains.

We used to have a 1987 Toyota Pickup with manual transmission with R22 120HP 4 cylinder engine and towed a 1000lb Chalet A-frame pop-up. The fuel economy was around 22MPG @ 60MPH. I could just barely get the CampLite 11 up to 55MPH on level interstate with that TV, never checked fuel economy with that rig.

Title: Re: How well do you do?
Post by: J_Westy on July 03, 2015, 02:33:19 PM
Quote from: DavidM on July 03, 2015, 12:42:26 PM
Quote from: J_Westy on July 03, 2015, 12:30:58 PM
Wind drag is the big one. It's a function of the coefficient of drag (Cd) and Speed Squared (Speed x Speed).

Well, not quite right.

Oops... You're absolutely right.. I had the Cd and Frontal Area lumped together in my head as single shape/size factor. Thanks.
Title: Re: How well do you do?
Post by: pjcd on January 05, 2017, 12:04:46 PM
I have a 2011 Duramax, when towing I get around 17mpg, (I'm little heavy on the foot). My old Dodge 3/4 ton truck got around 9mpg with a tail wind, going down hill.
Title: Re: How well do you do?
Post by: Pinstriper on January 05, 2017, 10:51:07 PM
12-13 mpg regardless of the F-150 5.4 or the 4Runner with the V-6.

The F-150 pulls a bit better, but actually the 4Runner has manual shifters and I can do better controlling the RPM/power balance on hills.

When not towing, the 4Runner gets 19 or so, the F-150 15-16.

The F-150 is a bit more stable ride when towing.
Title: Re: How well do you do?
Post by: tco2612 on January 07, 2017, 04:35:48 PM
16 MPG not towing 12 MPG towing a Camplite 11" 1994 K1500 Suburban 71000 miles that's 65 MPH and below,above that and it goes down fast.
Title: Re: How well do you do?
Post by: kybrowns1 on January 07, 2017, 09:07:25 PM
My 2009 Honda Van not towing traveling 65 mph will average 24-25mpg. That's loaded down with family.

Towing the 10.0, and loaded down with family and camping gear will get 18-20. Lately it's been closer to 18-19.

Air resistance is huge factor. I would buy a bike rack for the top of the van, but I don't want take a huge hit mpg when I travel across country during the Summers.


Sent from my iPhone using Tapatalk
Title: Re: How well do you do?
Post by: gbpack on January 08, 2017, 12:22:41 AM
With our Jeep Grand Cherokee (with V-8), we get 10-11 mpg towing our 21BHS and around 20 mpg when not towing (both while averaging 65 mph on the road). With a tailwind we have gotten 12-13 mpg and one time we only got 8 mpg driving into a stiff headwind of 30 mph. Overall we are happy with the performance and mileage results of the Jeep. We know that we are giving up some mpg with the V-8, but it's really great having all of that power and towing capacity, especially when towing in the mountains where I can accelerate and gain speed while going up a steep grade with no problem, if I want to. One time I decided to get out of the slow lane while going up a steep grade in WV because the semi in front of us had slowed down to about 40 mph because of the grade, so I decided to move out around him. We were fully loaded with our trailer in tow, but I hit the gas and we took off up the mountain and passed him like he was standing still. Absolutely love the Hemi V-8!
Title: Re: How well do you do?
Post by: Hey Voss on September 11, 2017, 07:07:44 PM
New personal best mpg! Towing a full 8.0 with an '05 VW Passat wagon TDI getting an average of 35mpg! That just 6mpg shy of what typically get towing nothing.
Title: Re: How well do you do?
Post by: FastEddieB on September 11, 2017, 07:24:15 PM
Ford Flex EcoBoost towing a 21BHS - typically 11 to 12.5 mpg towing at 55 mph as a general maximum.
Title: Re: How well do you do?
Post by: Merlin on September 11, 2017, 09:03:53 PM
Quote from: Hey Voss on September 11, 2017, 07:07:44 PM
New personal best mpg! Towing a full 8.0 with an '05 VW Passat wagon TDI getting an average of 35mpg! That just 6mpg shy of what typically get towing nothing.

That's just not fair. You need a handicap for a fair comparison to the rest of us. Go get a big boat anchor and drag it behind the trailer.  :o
Title: Re: How well do you do?
Post by: Diversteve on September 15, 2017, 09:56:39 PM
2013 Toyota Tundra 5.7L with tow package.
2014 14DBS.
Just returned today from a 4990 mile (round trip) to Glacier National Park.
Max towing speed 62 average 60 MPH.
Averaged 12.5 mpg!
Camp on!!!
Title: Re: How well do you do?
Post by: mojospeople on September 16, 2017, 04:59:15 PM
We're finding our new combo of my VW Touareg V6 (gas) and 2017 16 TBS loaded to about 4000 pounds and the car with two adults, 2 dogs is getting around 11 mpg running 65 - 70 mph. Not towing is about 20 mpg in mixed driving (50/50 city highway daily). Our recent trip to Colorado and back was 3200 miles with quite a bit of towing at 70 - 75 mph. We were fortunate to not encounter high winds on this trip which is pretty unusual across Kansas and Nebraska. The low on that trip was 9.5 mpg on two days through western Kansas and Nebraska when we were probably running closer to 75 mph. The high was 13 mpg in slower mountain driving over 4 passes in the rain. Guessing we were averaging 55 - 60 mph that day.

Overall I'm really happy with the towing performance of my little crossover SUV and happy I don't have to have a truck as my daily driver.
Title: Re: How well do you do?
Post by: Apollo on September 09, 2018, 11:56:16 AM
2018 F150 4x4 with the 2.7 twin turbo and a 21BHS, got an average of 9.25 mpg towing from MI to Myrtle Beach. This is a very hilly drive with a lot of steep grades and speeds were around 72 mph.