Gcwr

[dznf0g]

Originally Posted by aimcom

because, i can't imagine they have airstreams and hensleys in japan.

on the other hand, if they saw our ever more super-sized pick-up trucks over here, towing these ungainly box trailers (that pretty much convert into full sized houses) down our highways and then watch as someone glides past in a tidy car/airstream combo...they'd cotton on pretty darn quick, after all -- improved aerodynamics, low centre of gravity, build quality -- these are fundamental design principles that the Japanese have been using for many years to successfully export their vehicles to us here in north america and around the world...and the beauty of comprehending design aesthetics is inherent in all of us.

In a bigger sense, I can't help but reflect how fortunate we are here in north america to be able to experience and enjoy nature's vast, open, pristine and "serene" beauty in all of it's glory. I'm sure our Japanese friends would really appreciate that also.

happy streaming everyone!

Nissan of NA (as well as Toyota, Honda, et.al) Have products built for North America which have never nor will see Japan. They are specific for our market. As well, they have a rather large American field force who have seen everything you have...and more.
I interact with personnel from many other automakers quite often....their processes specs, etc are little different than the rest of us.

[Lance M]

Originally Posted by MrUKToad

A general question, does anyone know how a vehicle's GCWR is typically arrived at?

I have no idea how they come up with GCWR. It is something I'd like to understand, however.

What I can do is share with you my towing experience towing a 1972 Ambassador with both a 1970 Chevrolet C20 Custom Camper and a 2002 Toyota Sequoia SR5 2WD.

The '72 Ambassador weighs #5,710 with full propane tanks, full fresh water tank, empty holding tanks, loaded with the camping gear that is always in the trailer. No food or clothes.


My C20 has a 350/TH350 and 4.10 rear end ratio. It has both front and rear HD springs and front and rear stabilizers. It weighs #5,140 unloaded with me in it and full of fuel. Its GVWR is #7,500. FAWR is #2,700 RAWR is #5,200. I have no idea what its "tow rating" is and can't find it anywhere. I don't think it was something they published back then. I found this hard to read chart for the '69 model year on the net that shows the GCW as #10,250.

I wasn't able to find one of these charts for 1970, but I don't think it would be any different.
So if I subtract the curb weight of the truck from the GCW I can tow/haul
10,250 GCW
- 5,140 Curb weight
= 5,110
So as you can see I'll be exceeding the GCW by #600 when towing my nearly empty '72 Ambassador with my 3/4T C20. I do tow with this combination occasionally. Mostly weekend trips around Texas usually by myself. I stay off the big roads and so far, everything is fine. The old drum brakes have to be regularly adjusted. It is not a comfortable tow compared to the Sequoia.

The '02 Sequoia has a 240HP V8 with an auto trans. It weighs #5,320 unloaded full of fuel with me in it.
Ratings-
GVWR #6,500
GCWR of #11,800
Max gross trailer weight #6,500
Max tongue weight #650
I use the Sequoia to tow the Ambassador with the whole family of five. Fully loaded this combo weighs #12,680. 880 pounds above the GCWR of the Sequoia. It is a great setup that I feel very comfortable with.

Along with Toyota publishing a GCWR of #11,800 in the owner's manual, they also state "Do not exceed 72 km/h (45 mph) or the posted speed limit, whichever is lower. Because instability (swaying) of a tow vehicle-trailer combination usually increases as the speed increases, exceeding 72 km/h (45 mph) may cause loss of control."

So, there you have it. '02 Sequoia owners may only tow at 45mph.

For the Airstreamer's out there that are very concerned with braking, I would recommend you install disc brakes with an ABS module on your trailer.
Happy Streamin"!

[Melody Ranch]

You Guys remind me of an old Air Force expression....something about a monkey having sexual relations with a football.

[DKB_SATX]

re: that chart for the C20: I'll bet that sucker would HOWL at 65 mph with a 4:57 diff and a 400THM! That's how GearVendors makes money.

[aimcom]

Originally Posted by dznf0g

Nissan of NA (as well as Toyota, Honda, et.al) Have products built for North America which have never nor will see Japan. They are specific for our market. As well, they have a rather large American field force who have seen everything you have...and more.
I interact with personnel from many other automakers quite often....their processes specs, etc are little different than the rest of us.

I'm not sure if I understand your response to my earlier comments??? The Q45 isn't a north american product nor is it a standard/mainstream product built using common industry processes and specs.

The Nissan Cima (called the Infiniti Q45 in north america) was designed, engineered and built in Japan. The build quality, strength and power of the Q45 combine, in my opinion, to make one of the top automobiles that has been created in automotive history to date.

From a review of the Q45 that I read at the time–
"...Performance
...the first gen Q45s were performance oriented...Nissan's 4.5 liter V-8 VK45DE. Similar in design to Nissan's much vaulted V-6 VQ series engines, the VK45DE is all aluminum alloy with DOHC and 32 valves. This engine features variable length air induction system, continuously variable valve timing control system, titanium valves, modular cylinder heads, microfinished crankshaft, lightweight pistons (coated with molybdenum), super-silent single stage cam drive chain and a hydraulically driven cooling fan (powered by the steering system - allowing for low noise and power loss). All of this technology and craftsmanship is good for a velvety smooth 340 bhp @ 6,400 rpm and 333 ft-lbs of torque @ 4,000 rpm (over 80% of which is available from 1,700 rpm).

Our editors have driven the likes of Lexus, BMW, and Mercedes. The Merc and Lexus don't hold a dime to the new Q...The new Q excels in back country roads, especially in sport trim with 18" wheels/tires and active damping suspension...Infiniti has done a great job of balancing ride comfort and handling.

The smooth shifting 5 speed automatic works in tandem with the V-8 to produce seamless and quiet acceleration so that you forget how fast you're going until you look at the speedometer. Our editors enjoyed the flexibility of the manual-shifting mode but missed the instantaneous action offered by a true manual transmission. Still the manumatic mode held gears until near red line and could shave off a few seconds on a road course track.

True to its flagship high tech totem pole status, the Q gets vehicle dynamics control (a sophisticated form of traction control) paired up with limited slip differential so you can toss it around corners. Even then the Q’s suspension is amazingly supple and soaks up bumps and ruts in the highways.

Braking performance is on par with it's competitors boasting large four wheel vented discs, ABS (of course), electronic brake distribution (EBD), and mechanical/electronic braking assist. The latter senses when the driver is attempting to brake quickly and helps to apply more braking force."

Before I read about the Q45, I had never heard of molybdenum. Turns out, molybdenum has the sixth-highest melting point of any element. It readily forms hard, stable carbides in alloys, and for this reason is used in making high strength steel alloys and superalloys. (Apparently, much of the new engine technology found in the Q45, was developed for and derived from Infiniti’s formula 1 engines.)

Back at the time, I also read some interesting stories about the lengths they went to at the factory in Japan to ensure the build quality was of the highest possible order -- for example, they had the tightest possible panel fits of any vehicle, and etc. And then I also remember one time the owner from our local Krown rust control place (who spray the car's underbody every fall), went out of his way to show me how Infiniti had built the underneath edges to ensure there were no areas where dirt and water could penetrate and cause rust, and how "you just don't find that kind of thing on other vehicles".

In conclusion, if it were ever possible to meet the Q45's chief engineer from Japan, Mr. Teruo Miyauchi, I would first like to shake his hand and tell him how much I like his car. I don't know what experience he may or may not have with rv'ing, but I am fairly certain he would be very intrigued to see the combination that Andy from Canam helped us to create, by pairing his car with our international serenity (which we love), attached with a Hensley. I am also fairly certain he'd enjoy sharing the pleasure of putting this setup through it's paces, in a slalom course, and some double lane-change manouevers, especially with some back-to-back comparisons with boxy trailers and changing over to pick-ups, and then also with or without hensleys...

[dznf0g]

I am only saying that their reps are American who have grown up in the same auto environment as you and I and would not be "intrigued" by seeing a modified and potentially overloaded (I have no idea what you have) vehicle. Nissan has commercial products here that I don't believe, due to size, they have in Japan. ie. Titan, NV1500, NV2500, NV3500. I believe the NV200 IS sold in Japan. I am sure their reps have seen improperly loaded......just as I see it virtually weekly, if not daily in my commercial products. (I have no retail responsibilities currently, but sure saw it in retail as well when I was a retail rep)

[aimcom]

I will restate my position to see if we can conclude...
The max tow numbers that are published, and which are then quoted as a kind of definitive “thou shalt not” gospel, are likely based on the lowest common denominator using some kind of standardized / basic set-up. At least, if I were in charge of determining these numbers, that is how I would do it, seeing as I would have no control over what someone is attaching, or doing at, or to, the back of my vehicle.
I get the feeling that the word “modification”, as in the way you wrote your previous post, and saying “potentially overloaded”, infers almost as if someone is doing something that they otherwise should not be doing. If someone jacks up the rear end of their car and puts-on oversized tires. That would be such a modification, I agree, that would potential overload the vehicles designed handling and performance characteristics. I think the vehicles designers/engineers would be unhappy and dismayed, as it would result in a less stable vehicle, even though it may look “really cool” to the vehicle’s owner in their subjective opinion.
By comparison, creating an optimized towing solution, by using weight-distribution, a beefier hitch assembly employing the 4-point Hensley stability control system, towing a more aerodynamic trailer with a lower centre of gravity and employing products of higher build quality throughout, matching the build quality of the tow vehicle; these endeavours are achieved by the application of ingenuity and common sense.
An image of my set-up is posted here on airforums, which you should be able to find by clicking under my profile name. The vehicle engineers would likely be very pleased and excited, perhaps even feel as enthusiastic as I do, to see someone employing more advanced designs and solutions to unlock and optimize their vehicle’s potential. Perhaps “pleased and excited” is a better description of their possible feelings – I apologize if my earlier use of the word “intrigued” was somehow offensive to you.

[dznf0g]

You don't understand my position nor intent. done-let's move on.

[ROBERT CROSS]

Well we all agree the Q45 is a great vehicle....but not for us.

We rationalized our TV....as you did yours.

Can we all just shut-up and drive now.

Bob

[Denis4x4]

One has to remember that not all that long ago, the praise heaped on vehicles by the automotive press was in direct proportion to the advertising dollars spent in said magazine. It's been rumored that a senior advertising VP would "shop" the Motor Trend Car of the Year award based on the amount a manufacturer would spend to promote the MTCOTY award.

There used to be a top secret shop in SoCal filled with engineers and stylists for Nissan that commuted regularly to Japan.

Anybody remember the Datsun Bluebird? Early on, the marketing people at Datsun justified that name based on the fact that the top selling cars in the US in the sixties had names like Thunderbird, Eagle (AMC), Skylark (Buick), etc.

[rostam]

Originally Posted by aimcom

I will restate my position to see if we can conclude...
The max tow numbers that are published, and which are then quoted as a kind of definitive “thou shalt not” gospel, are likely based on the lowest common denominator using some kind of standardized / basic set-up. At least, if I were in charge of determining these numbers, that is how I would do it, seeing as I would have no control over what someone is attaching, or doing at, or to, the back of my vehicle.
I get the feeling that the word “modification”, as in the way you wrote your previous post, and saying “potentially overloaded”, infers almost as if someone is doing something that they otherwise should not be doing. If someone jacks up the rear end of their car and puts-on oversized tires. That would be such a modification, I agree, that would potential overload the vehicles designed handling and performance characteristics. I think the vehicles designers/engineers would be unhappy and dismayed, as it would result in a less stable vehicle, even though it may look “really cool” to the vehicle’s owner in their subjective opinion.
By comparison, creating an optimized towing solution, by using weight-distribution, a beefier hitch assembly employing the 4-point Hensley stability control system, towing a more aerodynamic trailer with a lower centre of gravity and employing products of higher build quality throughout, matching the build quality of the tow vehicle; these endeavours are achieved by the application of ingenuity and common sense.
An image of my set-up is posted here on airforums, which you should be able to find by clicking under my profile name. The vehicle engineers would likely be very pleased and excited, perhaps even feel as enthusiastic as I do, to see someone employing more advanced designs and solutions to unlock and optimize their vehicle’s potential. Perhaps “pleased and excited” is a better description of their possible feelings – I apologize if my earlier use of the word “intrigued” was somehow offensive to you.

Your vehicle's manual should CLEARLY state the tow rating, axle ratings, payload, tongue weight limit (with and without weight distribution), and GCVWR (if applicable). Instead of speculating on how the manufacturers come up with their tow ratings, how about you call/email them and just ask? Just go to their website, and click on contacts.

I am amazed as how you want to spin what the manufacturer says to make your point. You might just say you do not want to follow the manufacturer's rating (and that is fine with me; You are responsible for that anyway). But this much spin is just unbelievable.

[ROBERT CROSS]

They tend to spin a lot in the GWN. TETO.

Bob

[MrUKToad]

Originally Posted by rostam

Your vehicle's manual should CLEARLY state the tow rating, axle ratings, payload, tongue weight limit (with and without weight distribution), and GCVWR (if applicable). Instead of speculating on how the manufacturers come up with their tow ratings, how about you call/email them and just ask? Just go to their website, and click on contacts.

I am amazed as how you want to spin what the manufacturer says to make your point. You might just say you do not want to follow the manufacturer's rating (and that is fine with me; You are responsible for that anyway). But this much spin is just unbelievable.

Here's a nice potted look at how ratings are set, an article published by Truck Trend magazine a couple of years ago, with apologies to those who will have seen it before:

The Numbers Game: Current Practice & The Ratings - Consumer Feature - Truck Trend

Certainly you can't believe all you read but this piece does give attributed quotes from people in the Industry, which lends it quite a bit of credence in my view. As you see, it's not all about engineering and finite, measurable limits, hence the drive for an industry wide standard (yet to be adopted by the big domestic manufacturers!).

As you say though, Rostam, regardless of how ratings are derived and set, individual owners are responsible for their own vehicles and how they use them.

[dznf0g]

Although much is left out of this planning and process write up, it is 100% accurate based on my personal experience. GCWR is first in the process after market/competitive analysis AND anticipation of competitor product releases during the life cycle of your own soon to be offering.

[BradB]

And what exactly is that supposed to mean?

I suppose you think we all live in igloos up here in the GWN - might I remind you that certain parts (even excluding Alaska) of the United States are further north than I am right now in Southern Ontario.

I for one am quite sick of reading of the people who insist that you must have a 1-ton truck to tow a 34' Airstream. I'm not exceeding any factory number published with mine and have close to a 40% margin. It's almost like there is a great deal of mine is bigger than yours going on here.

Originally Posted by ROBERT CROSS

They tend to spin a lot in the GWN. TETO.

Bob

[rostam]

Originally Posted by MrUKToad

Here's a nice potted look at how ratings are set, an article published by Truck Trend magazine a couple of years ago, with apologies to those who will have seen it before:

The Numbers Game: Current Practice & The Ratings - Consumer Feature - Truck Trend

Certainly you can't believe all you read but this piece does give attributed quotes from people in the Industry, which lends it quite a bit of credence in my view. As you see, it's not all about engineering and finite, measurable limits, hence the drive for an industry wide standard (yet to be adopted by the big domestic manufacturers!).

As you say though, Rostam, regardless of how ratings are derived and set, individual owners are responsible for their own vehicles and how they use them.

I agree that tow rating are not accurate on most vehicles due to marketing (hence I am in favor of SAE standards). But the ratings are mostly over-stated not under-stated.

At the end of the day TETO.

[dznf0g]

Understand the SAE ratings will be performance based and lower than the capability specs. I have been assured by Brand Managers and engineering that we will still have the same specs available as we have today for capability spec'ing. The only thing the SAE spec will do is allow for apples to apples road performance to give the average person an understandable baseline. I predict it will add a lot of confusion and more fiery discourse on this forum relative to under sizing/over sizing tow vehicle selection.

[MrUKToad]

Originally Posted by rostam

I agree that tow rating are not accurate on most vehicles due to marketing (hence I am in favor of SAE standards). But the ratings are mostly over-stated not under-stated.

At the end of the day TETO.

What's TETO?

There are plenty of understated tow ratings (and thus, GCWR), the ubiquitous minivan being one of them. There's a standard 3,500 lb rating on every minivan produced in the last thirty years, regardless of manufacturer. The construction and performance of these vehicles has improved immeasurably over time and yet the rating stays the same.

The reasons why there are understated ratings rest with the manufacturers. I can speculate that they don't test these vehicles for towing performance so don't want to commit to a higher figure for fear of being sued. I can also speculate that the manufacturers would prefer that you bought a high margin truck for towing rather than the lower margin van; the marketing is clearly "trucks for towing" and "minivans for Soccer Moms". I couldn't back any of that up, of course, but you do get to wondering, especially when the recent crop of minivans will rival a half ton truck in most towing related specifications.

Anyway, that's just my view of it.

[AIRSTREAMMTL]

TETO: To Each Their Own (Internet slang)

[MrUKToad]

Originally Posted by AIRSTREAMMTL

TETO: To Each Their Own (Internet slang)

Aaaah, thank you.