wildnfree wrote: I have seen what large horsepower and racing slicks do to a unibody car so I know how tough they are.
I've seen them running 9's in the 1/4 mile without a problem...they work just fine.
John
1984 Ford B-700 school bus conversion, Thomas body
A bunch of other vehicles
3 nutty cats (Maya, Vierna, Briza)
One lazy dog (Marmaduke)
One wife (Liz)
"A wasted youth is better by far than a wise and productive old age"
-Jim Steinman
wildnfree wrote: I have seen what large horsepower and racing slicks do to a unibody car so I know how tough they are.
These rumors about unibody vehicles failing as a result of towing just won't die.
I challenged the forum several years ago to show me evidence of even ONE unibody vehicle that suffered damage from towing while pulling a trailer with a properly setup WD hitch. The closest someone came was pictures of an Astro van that had twisted the rear of the unibody enough to cause the rear doors to jam, but it turned out that guy was using way too much WD on a receiver that wasn't rated for WD at all. The lack of long side plates and forward mounting tabs on the hitch platform allowed twist that would normally have been mitigated through leverage. I did manage to dig up several posts on the web showing frame damage to trucks and SUVs (especially the new Toyotas) ironically enough, but no twisted unibodies.
At the end of the day, trucks have frames because it's the cheapest way to build something with maximum configuration flexibility. If you want to build a chassis that can support everything from a standard cab short bed 4x2 pickup, to a 9 passenger SUV with 4wd, then you need a ladder frame that you can stretch as needed. They are not better for towing, that's just marketing. They cost much less to make, ironic as the vehicles placed on them cost twice as much. Think of how much money would be spent designing unibody vehicles in ALL the configurations we like our trucks to be available in?!?!
Also consider vehicles like the Honda Ridgeline, which have already been used successfully to tow significant trailers by lots of people, yet Ridgelines come in only ONE configuration. Why, because they are unibody in design, and Honda has only engineered a single body style.
From a strictly engineering point of view, a unibody vehicle that is properly designed (strong welds and good material profiles) has the upper hand in rigidity vs. a frame. A ladder frame has only about 6" of web cross section height to control all the torsional forces placed on them. Yes the material is slightly thicker, though not as thick as you might think. There is a trick in play with ladder frame trucks because the frame is isolated by rubber body mounts, so the noodling of the frame under you is dampened and hidden in the cab. In contrast, a unibody vehicle often has similiar structural beams under the body, but they are welded to the rest of the vehicle allowing the full height of the shell to carry the torsional load. Depending on the actual body style in question, the web height could be 24-28 inches higher than the frame, drastically lowering the forces through leverage. The lack of noodling and increased rigidity allow the suspension to work as designed, keeping tires better in contact with the road. Just think about all this.
It's been my experience that setting up Weight Distribution hitches on unibody vehicles actually works much better. There is less chassis flex and hitch wind-up allowing more efficient transfer of weight with less spring bar takeup. Of course this all assumes a well-designed vehicle. I wouldn't make the same claims about a 1972 Dodge Dart.
And I've never damaged a unibody, bent a hitch, tore a mounting bolt or cracked windows. Nor has anyone else, as best I can research. Of course the challenge is still on, if you can show me something new I would LOVE to see it.
'04 Ford Freestar (Primary tow vehicle) '05 Subaru Forester (Backup tow vehicle) '65 Bethany popup (best popups ever made!) Looking for a tow vehicle Minivan towing
Quote: I've seen them running 9's in the 1/4 mile without a problem...they work just fine.
Are you using any subframe reinforcement? Maybe a rollcage?
I guess you have never seen a twisted up unibody drag car?
Quote: Also consider vehicles like the Honda Ridgeline, which have already been used successfully to tow significant trailers by lots of people, yet Ridgelines come in only ONE configuration.
Honda designed this as a truck, not a car, so it is designed to tow and haul heavier loads than a car.
Quote: Of course the challenge is still on, if you can show me something new I would LOVE to see it.
Nope, never heard of a problem. Of course there are probably ten thousand trucks towing a trailer to every unibody car towing a heavy trailer so I could go a whole lifetime without seeing ever seeing one, twisted up or not.
* This post was
edited 05/20/08 07:44pm by wildnfree *
Quote: From a strictly engineering point of view, a unibody vehicle that is properly designed (strong welds and good material profiles) has the upper hand in rigidity vs. a frame. A ladder frame has only about 6" of web cross section height to control all the torsional forces placed on them
Yes, they are stiffer, and a unibody can be built as strong as a ladder frame, but a unibody car is not as strong as a ladder frame 1/2 ton pickup. Truck frames flex under shock loads to dissipate stress that would crack a unibody car. Sure it can be reinforced or built stronger initially but to gain the strength you also gain the weight. Compare the GVW of your car to the GVW of a truck. The truck comes equipped from the factory to tow 4000 pounds without a WD hitch. WD is mandatory on your car to tow that weight.
I bet the GVW on a Ridgeline is lots higher than on your car, right?
Frame section height on my truck is 7.5 inches.
You may want to check with Andy Thompson, the owner of CanAm Rv, regarding a stronger hitch receiver if your toungue weight gets a bit too high. He sets up Dodge Chargers with custom receivers to tow Airstreams.
http://www.can-am-rv.com/
Happy travels!!!
Dennis
2008 Trail Cruiser C21RBH
2002 Toyota Highlander
wildnfree wrote: Honda designed this as a truck, not a car, so it is designed to tow and haul heavier loads than a car.
Honda took an existing platform from a minivan/SUV that was already successful and added a pickup truck to the line. The Ridgeline has essentially the same underpinnings as a Honda Pilot or Odyssey with minimal changes. Everything else you read on the internet that implies the Ridgeline is somehow built more "truck-like" is marketing propaganda, nothing more.
Quote: Nope, never heard of a problem. Of course there are probably ten thousand trucks towing a trailer to every unibody car towing a heavy trailer so I could go a whole lifetime without seeing ever seeing one, twisted up or not.
Maybe we can consider the thousands of unibody sedans and minivans Can-Am has setup over the years as a reference in this case. Andy has proved on several occasions that unibody vehicles work just fine when proper consideration is given to hitch design and application.
We are on the cutting edge of change here. You guys with your trucks are going to have to start getting comfortable seeing these smaller tow vehicles real quick. Gas prices what they are, there is NO WAY I would buy a large truck or SUV in the future unless I needed it's special abilities nearly every day. For the 5-10% of the time I need to tow a trailer, I'm much happier with the smaller, lighter tow vehicle.
As someone who has been to Europe several times, do you realize how rare full size trucks are over there? Last year gas was approx $9 a gallon. The "Tow vehicle of the year" was a Hyundai Sante Fe, which displaced the previous champion Subaru Forester 2.0 liter!
I saw a Toyota Corolla towing a 14~ft fiberglass boat while on my way home today. I don't know how long it will last or how it does pulling the boat out of the water 'cause I busted my crystal ball but, he was rolling along with traffic. He and his buddy didn't look terrified and I didn't see any stability problems. I couldn't tell what type of hitch he had. It looked like a flat receiver like I've seen on the internet for small vehicles. Times they are changing...
'05 2500HD Dodge 5.7L Hemi 5spd auto/3.73 SLT. 95k miles
ex '95 Cummins,'98 12v Cummins,'01.5 Cummins,'03 Cummins
'07 KZ Jag 28JFSS.
Yes, times are a changing. I have been soul seaching, and I don't see any way out.
If I can't take my 5th wheel camper and the toys I just won't go, no need to. My camper is support for doing other activities. My toys are too heavy for most small TV's and my camper is too. I can pull both with my truck.
Until I can come up with a better alternative I will just keep the status quo. But I will still keep looking.
Like Caddywhompus said, I suspect the RV business will change drastically in the next few years.
To put it in perspective a bit, how many 35' quad slide 5ers are sold in Europe?
I don't think I'd want to put a Subaru in front of my 9000# 34' TT. Different folks, different strokes. If I had a small TT, maybe a single axle 16' - 21' TT, or a boat, the Ridgeline would make a great TV. Just not the right tool for the job for me.
Hannibal wrote: I saw a Toyota Corolla towing a 14~ft fiberglass boat while on my way home today. Times they are changing...
The 2008 1.8L 130HP Corolla is tow rated for 1,500lbs. That is 500lbs more than the much larger, 300HP V8 Northstar Caddy DTS which has proven to be a great TV for larger trailers.
The North American auto makers need to get their act together soon and get real with their tow ratings. If not they will miss the boat on the new age of TV's and be sitting on the side lines watching the smaller import vehicles taking over the towing roles.
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