TV Emergency Handling - Lane Switch and Slalom

[TomR]

Hi All...In my continuing effort to learn about TV combinations and performance...I purchased RVLifestlye Issue Vol 35, No 7...which I beleive was a spring 2007 issue.

I ordered the older issue to read the test results performed by Andy Thomson od CanAM RV.
'
Andy took a number of tow vehicles to a test track and set up a high speed lane change and a slalom...as simulation for the most typical freeway speed emergency manuvers.

He used a 34' As and Hensley hitch as his test tow combination...and tested that set-up with a Jaguar, a Chrysler 300, a Frod Freestar, a Buick Rensevous, A VW Jetta, a Surburban.and two crew cab pick-up trucks...a GMC 1500HD and a GMC 2500HD Diesel.

Conclusion (in summary)...the low center of gravity vehicles w/low profile tires performed the best in theser emergency handling tests...the Suburban had the poorest test results...with the 3/4 ton diesel the second worst.

The Jaguar had the best test results with all of the other vehicles "handling" the emergency manuvers better than the "favorite" 3/4 ton diesel and the Suburban. BTW...the Suburban was tested with stock tires AND with a lower profile tire...and did perform better w/the lower profile tires.

The test did not include a stopping test...just the emergency performace handling. Maybe Andy will do a similar stopping test...although I seem to remeber an earlier test that showed the heavier pick-ups stoipping more slowly that the lighter tow vehicles...since the trailer brakes actually help stop the TV...not vice versa.

Before all the rants...please read the article rather than just reciting the same..."only bigger is better" towing answer.

Also, be sure to note in the article that the TVs were modified as CanAm always recommends...ie low profile tires, perhaps stiffer shocks if appropriate.

The logic of lower center of gravity, lower profile tires and firm suspension seems extremely strong for the freeway emergency handling Andy tested...how is it you can think a 2500HD with a very high center of gravity and very high ration tires could perform sudden manuvers well...in a freeway speed emergency?

The more I read...the more I think further study of this issue is appropriate. I do know that many are not open to this discussion...just want their big pick-em-up trucks!

For those who are curious...I suggest you try to get a copy of the article and read carefully. I am aware that CanAM as been discussed and dismissed by many...not sure that is the most open minded approach...back to the Turkey left-overs!

Tom R in Two Harbors, Minnesota

[Fyrzowt]

Interesting. Did you have any trouble finding the magazine? Where did you find it?
Thanks, Dave

[TomR]

Originally Posted by Fyrzowt

Interesting. Did you have any trouble finding the magazine? Where did you find it?
Thanks, Dave

Hi Dave...I ordered it online. My wife's mother is from Canada and I just subscribed to the magazine...in addition to ordering the "old" issue. I keep telling her we can visit Canada more often IF we had an AS.

I think I learned about the article (and the magazine) when it was mentioned by a poster in my earlier thread reagarding CanAM.

Tom R

[azflycaster]

Here it is:
Canada's Leading RV Lifestyle Magazine
You need to buy the magazine to read the whole article, but they also have several on line articles which talk about towing and tow vehicles. Very interesting reading.

[2airishuman]

Originally Posted by TomR

...set up a high speed lane change and a slalom...as simulation for the most typical freeway speed emergency manuvers.

The logic of lower center of gravity, lower profile tires and firm suspension seems extremely strong for the freeway emergency handling Andy tested...how is it you can think a 2500HD with a very high center of gravity and very high ration tires could perform sudden manuvers well...in a freeway speed emergency?

#1. herein lies the basic and critical flaw in this entire exercise.

the premise that 'lane changes' are the preferred freeway emergency maneuver...

when slowing down or stopping, WITHOUT changing lanes is almost ALWAYS the best action.

'lane changing' is in fact an extremely dangerous action, and the actual cause of many avoidable highway collisions....

and sadly OVER used by modern (metro loop) inexperienced drivers.

yes there are occasional situations where lane changing might be the preferred action.

but NOT many.

when towing out on the 'high seas' of the interstate, veteran long haul drivers give a wider birth, as they should.

yes i realize 'trucker drafting' happens but that again is a different issue.

approaching metro areas the behaviors change because of the local drivers and their behaviors...

towing into/around metro areas, we need to pick the ideal lane, be aware of those around us, use lights and signals and NOT be part of the race...

#2. why the surprise that a low center car with low profile tires and tuned suspension handle better?

of course they do.

but towing isn't about sports car handling. towing IS about behaving like the better professional overtheroad truckers do...

-anticipate, leave space, know YOUR stopping distance, and give a wide birth to the nuts in cars darting in-n-out of traffic...

in other words safe towing is about reducing the potential of high speed events.

it is NOT about closed course high speed lane changing, leave that to the sports cars...

towing is not about following so close that the only option is swerving into another lane...

one of the many advantages to a truck is the ability to see 'over and beyond' the small cars in front of us.

rv towing is a completely different driver skill set.

yes big trucks and suvs are over used for daily drivers and have inherent issues (mpg, roll over, head/neck injuries, braking)

but again towing, and especially a BIG trailer is about other issues.

using the jag as an example...

-limited cargo, limited vision, limited off road, in the grass, rv park, bookdocking potential.

i would NOT choose to tow a 34 with a jag, even if the jag was FREE...

give most a/s have marginally adequate cargo space, the truck IS for hauling crap!

3. low profile tires....

again an absolute need for performance driving, but for towing?

http://www.airforums.com/forums/270722-post12.html

so the demand from towing tires and the characteristics of good towing tires are very different from performance tires.

high mileage, good punture resistance, extra load capacity, grip in all conditions, resistance to curbs and pot holes, and so on...

yes there are now 20 inch truck tires with improved load capacity but again...

i would NOT choose to tow the 34 with 20s, even if the 20s were FREE!

4. suspension

the attributes of a great towing suspension are not the same as a great handling performance suspension...

(porsche cayenne asside)

load carrying capacity, adjustablilty, durability, steering that ISN'T to tight, and comfort are needed for towing.

while tight steering, good high speed on center feel, properly balanced under/over steer, good road feedback, and so on define performance steering.

5. braking

the few published comparisions demonstrate that a big truck (f-250) towing a trailer with disc brakes...

stops in less distance than the truck alone.

BUT the tv still needs to be able to stop/control the trailer, should the trailer brakes fail or malfunction.
____________________________________

i love driving fast on closed courses and tracks.

i love what great sports cars can do.

i'm sure the towing exercise was fun, i'd love to have been driving (not using MY trailer)...

but folks looking for sports car handling and attributes while towing...

need to understand that is NOT what safe towing is about...

don't get lost in the performance specs and keep the BIG picture in view.

again learning to behave like the BIG/GROWN UP truck drivers do is the responsibility that comes with towing.

cheers
2air'

[TomR]

2air...I am disappointed .

I agree with just about everything you say...but that does not negate the value of an emergency avoidance manuver test. Yes, tow like a trucker (or an adult), yes, try to stop instead of change lanes if possible...but the rest of your narrative is not up to your normally highly analytical, intellectually curious posts.

Seems to me...

1) Low center of gravity...are you saying that a higher center of gravity is better for towing?

2) Low profile tires...YOU may not want 20" but IF they have adequate weight ratings...why would a HIGHER profile tire (and the extra "sway" that may accopmpany)...be BETTER for towing?

3) Slalom and Lane change tests...no one said that this was a sports car test...why would it be BETTER to tow with a vehicle that performs POORLY when taxed in an extreme, emergency type situation? Notice I said nothing about it being the ONLY factor in testing a tow vehicle for emergency response.

4) Have you read the article...I trust you have.

In my opinion, this article is a valuable, controlled test of the emergency handling reactions of a sample of tow vehicle combinations...with a Hensley and a 34' AS...and the most often recommended heavy tow vehicles (Suburban and 3/4 ton CC Diesel) did poorly...at a MINIMUM it is food for thought and further discussion

I wonder if Andy at CanAm has done similar braking tests? Seems like I saw a reference to such?

Come on now...you Duramax/Allison owners...let's have some "on target" discussion instead of diversion and anecdote...Tom R

[2airishuman]

i've already tried to explain why low profile tires are a negative....

and when it comes to suvs or trucks low profile tires CONTRIBUTE to roll over accidents and loss of control events.

no i didn't suggest a higher center of gravity is better.

an adequate tv is better.

IF center of gravity is your concern (it isn't mine) LOWER the truck...

slalom and lane change exercises demonstate characteristics of the hensley...

but are a misdirection of the safe and proper towing set up issue.

that's the point.

cheers
2air'

[CanoeStream]

The frequently linked video with a Cayenne swerving towing an Airstream vs. SOB shows slight differences in the driver input IMO. Where's the validity? So much of this is subjective. It is said the CG is lower if you have your water tanks full -- variables abound and I'm not sure this can be quantified. Yes, a truck or SUV has a high CG. If I'm so out of control that I have to worry about that, I fear both TV & trailer are going to take a major hit -- I'll wish only that I can walk away.

When the trailer tries to take over and do the steering I think I'd rather be driving a tow vehicle that weighs 3 tons rather than 2. Sorry to pull him in to this but 85MH325 said earlier today, ""You can move a train with a sewing machine motor, if it's geared properly." Stopping the train once it's moving is another matter altogether."

[2airishuman]

the editors at grassroots motorsports did a 'comparison' that made the cover back in march 2003...

they pitted a honda odyssey minivan against a porsche 356 and a jaguar (series 2) xke...

on an autocross course!

the minivan lap times were equal (within 0.01 sec) to the porsche...

and they both beat the jag!

it was fun to read, and demonstrated that...

-the modern minivan handles well,
-a japanese fwd box can out race 30-40 year old english and german 'sports cars'..
-old porsches are not very fast...
-old jags look cool in the paddock...
and
-car guys get to do fun/crazy stuff....

but not many minivans entered autocross events as a result.

what's any of this have to do with towing?

the odyssey minivan was normally used to tow the editors real autocross car

so maybe it's a little bit of a surprise that a modern jag can win a handling comparison...

against a diesel truck or a bourbon...

but i'm a little disappointed the 300m couldn't take the jag...

and i'd gladly take the bathtub porsche if given the opportunity.

cheers
2air'

[TomR]

Originally Posted by 2airishuman

the editors at grassroots motorsports did a 'comparison' that made the cover back in march 2003...

they pitted a honda odyssey minivan against a porsche 356 and a jaguar (series 2) xke...

on an autocross course!

the minivan lap times were equal (within 0.01 sec) to the porsche...

and they both beat the jag!

it was fun to read, and demonstrated that...

-the modern minivan handles well,
-a japanese fwd box can out race 30-40 year old english and german 'sports cars'..
-old porsches are not very fast...
-old jags look cool in the paddock...
and
-car guys get to do fun/crazy stuff....

but not many minivans entered autocross events as a result.

what's any of this have to do with towing?

the odyssey minivan was normally used to tow the editors real autocross car

so maybe it's a little bit of a surprise that a modern jag can win a handling comparison...

against a diesel truck or a bourbon...

but i'm a little disappointed the 300m couldn't take the jag...

and i'd gladly take the bathtub porsche if given the opportunity.

cheers
2air'

Ya...but where did the Duramax/Allison finish?

Tom R

[Mikethefixit]

I agree with most of what 2 air has said. This in not gospel but 45 yrs OTR experence speaking.
#1 Stay away from Big Trucks. I mean way away. If U can't see that drivers mirrors ,he can't see U.
#2 Go around Major metro areas if an alter. route is available.
#3 If U have to go thru and its mutipule lanes, travel in the 2nd lane from the right ,to allow exits and entrances. No lane changing U dont gain anything.
#4 NO TAILGATING Leave U aplace to go when things come to a HALT
# 5 Dont hurry, Hurry wastes fuel and can get U hurt.Leave a little early.
2 air and I have big trucks for a reason,like someone said U can start a freight train with a sewing machine motor.But OH BOY when ya try to stop
#6 BE SAFE EVERYONE
I want to talk to U here and not READ about ya in the Papers
Roger

[2airishuman]

Originally Posted by TomR

Ya...but where did the Duramax/Allison finish? Tom R

i couldn't tell ya, i drive a blue oval!

cheers
2air'

of course with the 19th century rigid front axle the ford is no slalom winner!

Fast On Race Day!

[TomR]

Originally Posted by Mikethefixit

2 air and I have big trucks for a reason,like someone said U can start a freight train with a sewing machine motor.But OH BOY when ya try to stop
Roger

Hi Roger...one thing I am confused about...I thought the trailer brakes stopped the trailer...and in fact a well set brake controller should be set to come on strong enough that the trailer brakes actually helped stop the tow vehicle??

Someone stated that a well set up trailer braking system w/TV should stop the two (ie trailer plus TV) in a shorter distance than just the TV stops on its own?? (please for this ignore any potential failure of trailer brakes!). Seems like the truck needs big brakes mostly to stop the big truck? ...and just in case the trailer brakes fail when you are going down a steep mountain pass.

Do the truck brakes stop the trailer or is it the trailer brakes that not only stop the trailer but actually help the truck stop in less distance than it stops by itself???...as other have suggested?

Thanks...Tom R

[CanoeStream]

Originally Posted by TomR

Do the truck brakes stop the trailer or is it....

In a perfect world? All towing setups will "lose it" at some point -- some earlier than others. A fly-by-wire F-16 has triple redundant systems but early experience revealed that Murphy's law led to the inevitable. A brake controller is a single layer system -- stay on top of the adjustments or not, it is never perfect. Until that point I do count on the trailer brakes to usually stop the trailer. Yes.

Go back 4-5 years and you'll find "Will Hensley's allow me to tow thru snow to the ski slope" threads. Not a good idea.

Originally Posted by Jim Croce

You don't tug on Superman's cape,You don't spit into the wind,You don't pull the mask off the old Lone Ranger, And you don't mess around with Jim, da do da do...

What constitutes a reasonably stout tow situation is open to various views. Those opinions are hard to shake. I once thought a Volvo XC70 Cross Country would get me into Airstreaming just fine. Reserves are extraordinarily useful for any situation. Read 2air's scenarios for the real life experience they suggest. Given a problem, I feel my tow vehicle alone will allow me to bring my combined rig to a strong, controlled stop if I drive with a reasonable 3-dimensional awareness of driving conditions and my surroundings. I do not buy the idea that my GMC will lose it before a Dodge Intrepid, Jag or Cayenne. It's a margin of comfort thing. Experience will back up my level of comfort.

[HiHoAgRV]

Flame fodder

"The quickest way to prove you are truly an expert is to find a renounded
person in the field with tons of historical data showing it can't be done, then show it can be done." (my Patent Atty)

Low, wide, lots of grip sounds like a good start for a TV. Unfortunately my Jag has too many miles and not enough grunt for my style of towing . Where can we find data that shows a 3/4 ton stops or avoids (lane change) an incident better than any other vehicle?

"when things hit the fan"..ok I started the next reply...

What is the old Porsche advert? The only thing better than surviving an accident is avoiding it.

[TomR]

Originally Posted by CanoeStream

Given a problem, I feel my tow vehicle alone will allow me to bring my combined rig to a strong, controlled stop if I drive with a reasonable 3-dimensional awareness of driving conditions and my surroundings.

I believe I read in one of Andy's (CanAm) posts that they tested braking on their TV and trailer combinations on some steep grades (faux mountain pass?) without trailer brakes and found they worked fine in such emergency...I also think it was CanAm that observed that the TV stopped quicker WITH trailer in tow than without?

The triple axel 34' w/6 disc's combined with any modern TV should bring both to a quick stop...pending failure of trailer brakes/controller...in which case the TV should be able to bring the combo to a stop in a reasonable distance...certainly wouldn't set any records.

BTW...where is the "controlled" testing of the common wisdom...side by side like CanAm does?? Oh, I guess since it is common wisdom we all need to accept w/o challenge?

One other thing...I am NOT convinced that CanAm is absolutely correct, but I think they have done more than anyone else to document their position...and they have backed it up with what 50 year of testing and selling...and what other dealer has various TV set-ups available for a customer to "demo".

CanAm does have my attention on the issue of lateral control testing...and that the higher center of gravity TVs w/the very high profile tires MAY be much more subject to instability and roll. Again, read the article about how the Suburban back wheels lost contact with the pavement at very moderate speeds compared to the "un-fitting" TVs which stayed in contact with the pavement and tracked extremely well with much more aggressive test limits.

I am not sure that claimed result should be dismissed w/o further thought??? Like you all like to say...you have to plan for the unexpected...and sudden lateral turns certainly are among the likely possibilities in an emergency manuver (sorry, given that the first choice is to prevent such emergency )

I genuinely have a curious and open mind on CanAM's premise and practice...perhaps w/o the benefit of experience...and perhaps w/o the burden of already having decided...Tom R

Tom R

[TomR]

Originally Posted by HiHoAgRV

Flame fodder
Low, wide, lots of grip sounds like a good start for a TV. Unfortunately my Jag has too many miles and not enough grunt for my style of towing . Where can we find data that shows a 3/4 ton stops or avoids (lane change) an incident better than any other vehicle?

Thank You...Tom R

[Druupy]

Real world?

When was the last time you had to use the brakes on an open interstate?

When I have had to "USE THE BRAKES" , as in, "LOCK-UP ALL 8"?

The times I had to stop on the interstate there were:

3 cars in the lane to the right
3 cars in the lane to the left
1 car in the HOV lane that "HAS TO MAKE THAT EXIT" or
"Wait, this isn't my exit, I need to merge NOW".

When was the last time you were cut off and it was only you and the idiot that cut you off? Idiot drivers are created by circumstance. That same driver not being able to navigate and handle the stress of real traffic, instant idiot.

Your chance of incountering drastic changes of wind speed and direction?
Guaranteed.
Your chance of successfully using a high speed avoidance manuver?
You are more likely to win the lottery.

[Inland RV Center, In]

Originally Posted by Druupy

Real world?

Your chance of successfully using a high speed avoidance manuver?
You are more likely to win the lottery.

Not if your tow vehicle was equipped with Saf-T-Tow.

Making it available, once again, is in the works.

Andy

[slowmover]

I'd like to be able to say I'd driven some of these quite interesting car/trailer combos so as to be able to offer an opinion with experience (oh, yeah, the '76 Cadillac and the '75 Silver Streak on and off over a 12 year period [my parents rig]). The gas mileage was 6-7 and you had to keep WOT throttle for long minutes. So what? The engine and trans were still un-opened and original at 187,000 miles when it was sold.

I'd like to say I've performed emergency lane change manuevers in a big truck; well, I have, and lived to tell about it. My tractor weighed 18,000 and the empty trailer 9,000 for a tare weight of 27,000 (meaning the load would be as close to 53,000 as possible). Think there was any discussion about the TV weighing more, or the wheelbase being longer as a safety item?

I know of more than one rollover where the pickup truck tow vehicle was the likely cause.

I bought a Hensley precisely because of this issue (rollovers) and spent the first 20-minutes I owned it doing nothing BUT violent lane changes from 35 mph and up (sorry, cat, sorta forget you were back there). I couldn't shake it loose (as I could with the previous hitch rigging at 40 mph) and never gave the 60-day trial period another thought. (And my pains in getting hitch height, etc, correct are in other threads).

Comparing a big rig and a travel trailer pulled by car or truck isn't helpful, they are different in fundamental ways. But it is certainly true that the experience and the skills I learned are applicable in RV towing. In short, distance and speed are everything.

2Air, I'd like to see a source cited about low-profile tires contributing to p/u rollover. The tires spec'd by the OEM's are generally known to be long-lasting and up to what owners might put them through, and this, by itself, doesn't preclude changing them for a specific application -- on or off road -- where performance is bettered. Do you refer to decreased load capacity?

As to brakes, well, NOTHING stops worse than a big truck, loaded or empty. Their braking system is so poor as to be nearly criminal-neglect by our so called "safety nazis" at the DOT.

As to a car, where the axle and gvwr limits are within spec . . I imagine Andy Thomson's old man would have QUIT using cars ca. 1960 if car brakes weren't capable of handling an Airstream in good working order.

What seems to be forgotten is that big cars haven't been produced in this country since 1979: motors with big torque and wheelbases above 120". From that point until about ten years ago trucks were the only vehicles with reasonable power . . and consumers came to like their other utilities despite their propensity to roll over at a rate that should be sobering.

It would be one thing if this towing issue were new to the world of cars & trucks (it ain't), and if the problem being examined were hypothetical (it ain't).

As an exercise, a debate, I don't see facts in contention: court cases and legal rulings; examples of same in other countries (Australia, if I recall correctly, REQUIRES parking brakes on trailers; why don't we?), other governmental regulations or other legislative initiatives citing good reasons to (whatever).

What I do see is a lot of opinion. So here's mine: I've driven both, and the car is demonstrably safer to drive, (that is fact based); easier to live with when not towing, and a heckuva lot more comfortable to ride in.

The advantage of a truck is in it's utility, the reason I own one (business). That electronic engine, transmission, "stability" controls and the rest have made them better is not in question. But the cars that have received them are better as well.

If I want to use a car to pull a trailer then why not just recommend I use the services of Can Am and be done with it. It also appears that they are expert in setting up hitches, and I'd be willing to bet that maybe one or two of us could pass inspection in that regard.

Finally:

So, again, why are aerodynamic, independently-suspended, unibody, low-center-of-gravity trailers superior to boxy, body-on-frame, leaf-sprung trailers with high, uncertain CG?