I've got a semi-hypothetical question for anyone who'd like to take it on. First, the givens: my wife and I just got back from a 5-day trip to Ouray, CO from our home in Albuquerque, NM, towing a new-since-April 19" Fun Seeker X-189FBR (www.cruiserrv.com) with a 2007 Honda Ridgeline RTX.
No, we have not weighed the trailer but, using the manufacturer's own data for dry weight, weight of options and being honest about what we carry (TV, contents of galley, wardrobe, contents of one basement storage) with 1/2 tank of fresh water and empty gray and black water tanks, I estimate that the trailer, loaded, weighs 3500 lbs.
And, no, we did not buy the Ridgeline thinking it was a truck. We bought it precisely because it is, for us, a good combination of car with some truck-like capabilities. The RTX is factory-equipped for towing and the rating is 5,000 pounds.
So, during this trip we went from an elevation of 5,200 feet on the west side of Albuquerque to 10,222 feet at the top of Lizard Head Pass...and we both thought the Ridgeline handled it well. At the times when it really had to gear down, the speed limit on the road was usually posted 20-30 mph anyway for sharp turns. Of course, there were many "lesser" grades to deal with, as well.
Over the entire trip, we averaged 11.5 mpg which is slightly better that what we used to get with our Ford Triton V10-based 24" Class C motorhome on the flat...and a whole lot better than the 9 mpg we would get with it when towing a small car (also on the flat). So, no real complaints.
But here's the hypothetical part: while the evidence would show that the Ridgeline's 247 hp/245 lbs-ft. V-6 was up to the job with reasonably good efficiency...I began to wonder what would be the result if we had towed the same trailer with other vehicles in the same category. For instance, the Toyota Tacoma's V-6 produces 236 hp and 266 lbs-ft of torque. Yet it's rated to tow 6,500 pounds (by virtue of having full body-on-frame construction?). The Nissan Frontier has a more powerful, torquier 261 hp/281 lbs-ft V-6 but it is rated at 6,100 pounds. The City/Hwy EPA ratings for both of these trucks are within a stone's throw of each other as well as that of the Ridgeline.
So would the performance and economy of either/both of these trucks likely have been close to a draw with the Ridgeline? Would their actual economy have been close to ours? Or would it have been better? We were under the Ridgeline's tow limit...but we would have been "more under" with the other two. Or, to put it another way, what if the other two trucks in this comparison were the Tundra and the Titan, in the next size up? Do you (generally) get better mileage and more efficient operation from an "understressed" powertrain, when the tow vehicle is rated to carry far, far more than what you've got hitched to it?
Ouch, after reading all of that, my brain hurts. The answer is a very definite, probably maybe.
There is a middle ground where you will get better performance with a mid size engine running just below it's power peak. too large and you waste a lot of fuel with a lightly loaded engine.
Ken
KE5DFR
Vintage 1979 Silver Streak Supreme Rocket toted by a 2002 F350, crewcab dually, 7.3L,4.10 axle,SCMT. Travel with two miniature Schnauzers and one African Gray parrot. Practicing for retirement!
Thanks for the reply...sorry if I overdid it. Seemed to me like online forums are where fully-developed discussions are held. Didn't realize y'all were texting here. :-)
Towing efficiency IMO = ton-miles/gallon of fuel. In that situation, the larger vehicle is usually more efficient than a small vehicle.
For example, our Chevy 2500HD & Arctic Fox 29V combination weighs about 17,500# and we get about 11 MPG. => 8.75 tons X 11 MPG = 96.25 ton-miles/gallon of fuel
By comparison, our Beaver Patriot DP pulling our Jeep Grand Cherokee weighed about 32,000# and got 8.4 MPG. => 16 tons X 8.4 MPG = 134.4 ton-miles/gallon of fuel
And your Ridgeline/FunSeeker if loaded to GCVWR of 11,050# => 5.52 tons X 11.5 MPG = 63.54 ton-miles/gallon of fuel.
So while your rig used less fuel in an absolute sense, it was only half as efficient as our old DP.
Now, if you'd pulled it with our Chevy, we'd probably have gotten about 15 MPG, which would make for 8,000# + 5,000# = 6.5 tons X 15 MPG = 97.5 ton-miles/gallon of fuel.
Isn't it interesting how my Chevy is half again as efficient as the Ridgeline?
BTW, you'd get similar results to your Ridgeline if you towed it with a different gas-powered TV. Some gasoline trucks/SUVs are born gas hogs, like our '88 F250 that rarely gets over 10 MPG empty, and some might be more efficient when towing but not by more than a minor amount because of the additional weight, tire size, etc of the larger trucks/SUVs.
Steve & C. J.
"Gracie" the Rough Collie & "Bo'sun" the Bichon Frise
Now I'VE got a headache! Suffice to say that in my travels, I've discovered that sometimes a moderately loaded powerhouse of a vehicle is more fuel-efficient than a severely overloaded coffee grinder! (I'm not putting down smaller vehicles towing smaller trailers; did that myself for years, until my family got too big).
2003 GMC Sierra Crew HD; 6.0L; Prodigy
2006 Thor Tundra 30RL-DSL; Reese Strait-Line & Dual-cam HP
2001 Honda Elite Scooter
Jim & Gayle Bryant
Murphy's Law: "Anything that CAN happen, WILL."
Bryant's Law: "31 years of RVing? Probably already HAS."
Steve appears to have placed a formula to this that makes a bunch of sense. I would say that your effeciency would have to almost certainly increase.
That being said, I do belive that Tacoma and Frontiers capcities for towing might be grossly exagerated, and from experience they have been in previous years (in the 90's).
Todd and Becky King With Nathan, Amanda, Adam, Gillian and Hannah
1999 F350 SRW CC Powerstroke/2003 Dutchmen 29Q Sport
Efficiency vs. cost - Interesting question. Yes, the DP towing a Jeep becomes more efficient ton-miles, but at what cost with the difference between the prices of gasoline and diesel and MPG. That's what I would be looking at, the bottom line of my wallet!
Arnie & Mary
2004 4WD Dodge Durango w/5.7L Hemi/3.55/Tow Package
Reese WDH w/Dual Cam, Prodigy Brake Controller
2008 Jayco JayFeather 25F LGT
USAF (Ret) 1962-84 B-52D/G & FB-111A
Ham - N1BAC My Traveling Web Page
Thanks for the reply...sorry if I overdid it. Seemed to me like online forums are where fully-developed discussions are held. Didn't realize y'all were texting here. :-)
Hey I was just yanking on your chain....
I am an engineer and have often dealt with issues that could not be modeled to a formula to give a single answer. There is a lot of variables to analyze here. As you start the process, it seems to grow and you wonder will the end ever be insight.
Yeah, and don't forget to throw in wind drag for the specific TT/TV where drag is a square function of speed... Double your speed and your drag coefficient goes up by a factor of 4... Then throw in the equation for weight/HP/torque...
More math than I want to do
Les
2000 Ford F-250SD, XLT, 4X4 Off Road, SuperCab
w/ 6.8L (415 C.I.) V-10/3:73LS/4R100
Banks Power Pack w/Trans Command & OttoMind
2006 Nomad 3150 Double Slide (Bunkhouse)
Hensley Arrow
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