Manufacturer's Tow Ratings

[truckasaurus]

For myself I'm not so terrified of being sued it's just that I feel that the manufacturer is telling me something with their published information that has value. When they say their vehicle is good to tow x I interpret that as best I can. If they say our vehicle is only good to tow 3000 lbs I figure they either have little confidence in it's tow abilities over and above 3000 lbs and/ or don't feel there's much of a reward for them as previous covered to warrant the risk. Either way what I hear is that the vehicle isn't what I'm looking for to tow 6000 lbw. Now, obviously it might be an awesome vehicle for towing 6000 lbs but I personally feel that I'd like one from a manufacturer who stands ups and says they built it to tow at least 6000 lbs. I'm not hating on cars and SUV's just expressing a point of view. I'm glad there's variety in the world and variety is why some of us see a TV rated at 3000 lbs towing 6000 lbs and take from that the rating is bogus and means nothing at all, and then others see an interpretation of information that doesn't sit right.

I can see why there's so much passion about the subject it's just weird that the bulk of us probably want the same thing in the end it's just how we want to get it done that differs.

I do want to add a quick list of things that don't affect tow ratings as it might cut down on the distractions:
lower profile tires
tire pressure
bigger engine
bigger transmission
better brakes
air bags
fancy hitch
altering trailer balance
trailer brakes
avoiding hills
driving slowly
driving extra carefully
the weather
what was used in the 50's, 60's 70's, 80's, 90's, though to today

* some of the above will make towing easier and safer but the tow rating of the vehicle from the original manufacturer never changes.

[Chuck]

Originally Posted by truckasaurus

... they built it to tow at least 6000 lbs.

See, this is what I'm seeing: people take these numbers and interpret them to mean all different things.
another is "..my pickup was designed to tow"---it was not "designed" to do any such thing. It was "designed" for tradesmen to carry bulky tools and materials from local lumber/freight depots to a local construction site.
As it turns out, they "can" tow stuff, too. And when mfg's found that more and more people want a truck for just that purpose, they started marketing to that effect.
So, was the truck built "to tow" x amount? or does it just turn out that it was built "to do other stuff and be profitable at a certain price point"....and as it turned out after evaluating the finished product, it was decided that it can tow a certain amount of weight without ______ {something negative or undesireable} happening? And just what exactly is that negative thing? A safety issue? premature wear? catastrophic disruption of the time/space continuum?
I guess everybody has to interpret for themselves...the easiest conclusion is to just stay under that number.

Anything that was truly "designed" to tow would have been equipped by the manufacturer with all (or most) of the items in your list (save for the behavioral ones).

Originally Posted by truckasaurus

lower profile tires
tire pressure
bigger engine
bigger transmission
better brakes
air bags
fancy hitch
altering trailer balance
trailer brakes
avoiding hills
driving slowly
driving extra carefully
the weather
what was used in the 50's, 60's 70's, 80's, 90's, though to today

* some of the above will make towing easier and safer but the tow rating of the vehicle from the original manufacturer never changes.

cuz they didn't install it. They're not going to take responsibility for anything they didn't put together, themselves.

[MrUKToad]

A while back I posted a link to an article in Truck Trend Magazine that went a little way to exploring how tow ratings were set. It was written in light of the proposed new SAE standardized ratings.

The gist of the piece was that marketing was the main driver for tow ratings and whilst some testing was done, it was mostly after the rating was set, to check that it was indeed viable.

A couple of people dismissed the article saying "you shouldn't believe all that you read on the Internet", which is true, but this piece was from a reputable publication and quoted industry sources by name; in my book that's as true an account as you're ever going to get.

My apologies to those who will already have seen the article but I'm adding the link again. You will note that the quotes in the piece are not from a certain business in Canada but actual people from actual manufacturers. Of course, you're free to draw your own conclusions but I think that it backs up what OP's point was at the start of the thread.

The Numbers Game: Current Practice & The Ratings - Consumer Feature - Truck Trend Page 2

[dznf0g]

"It all starts when we're developing a platform," adds Richard Miller, regional product manager for Nissan trucks. "We research the market and the customers, see what our competitors are doing, and decide where we want to position our vehicle. If we want to be the leader, we'll check competitors' ratings, project where we expect them to be by the time we launch our new platform, and set that as a target. That target is then cascaded to the different engineering and component groups, who test and develop their parts to meet it."

This is the most important quote of the article. Of course a new design proposal begins with market analysis. I think that is a far cry from those who say marketing fiddles with the numbers AFTER a vehicle is developed.

The red text is the crux of our discussion, IMO. If you exceed those component engineering parameters, you run the risk of affecting durability, and reliability, at a minimum. And risk safety, depending on the component, potentially.

Engineering does "build in" a safety margin, but like I said before...it is not nearly as large as some here on the forum believe and push.

Read more: The Numbers Game: Current Practice & The Ratings - Consumer Feature - Truck Trend Page 2

[dznf0g]

And this:
"Not surprisingly, tow vehicle develop-ment and testing is extensive. It begins at the component level, in labs and on benches, continues through the subsystem level (chassis, brakes, powertrain) and culminates with complete vehicles from early prototypes through production. "We do a lot of hot-room and cold-room testing," says Chrysler's Cairns. "We have goal temperatures for critical components, so we take thermal data from fully instrumented vehicles in test cells and match that against CFD [computational fluid dynamics]."

Read more: Capability Testing & New SAE Standards - Consumer Feature - Truck Trend Page 3

[dznf0g]

And I have been saying this all along....it is a performance based test so non-technical folks can compare apples to apples on a road test to their preferred travel requirement. Speed....etc. All the existing numbers will still be available (form GM anyway) for a technical specification of a customer's desired vehicle, so they can spec a vehicle to be operated under engineering established durability, reliability and safety parameters.

"SAE J2807 will say, 'Here are your performance requirements to set a GCWR--how fast you can get up a hill, how cool the truck is while doing it, how well the combination handles, etc.,'" says GM's Krouse. "Then the last section says, 'Now that you have validated to this GCWR, here's how to calculate your trailer weight rating from it.'

Read more: Capability Testing & New SAE Standards - Consumer Feature - Truck Trend Page 3

[Denis4x4]

As the OP, I find it fascinating how this thread has morphed. I still think that manufacturers ignore the engineering and testing on vehicles other than SUV's and pickups simply because there is no profit motive.

That was the basis for the original thread.

[mstephens]

In short, there are two questions:
1. Does the TV do the required things to haul the load? Braking, climbing, maneuvering and so on.

2. Does the TV breakdown while doing it?

If the answers are yes and no, is there really much more to it?

[xrvr]

And number three should be does it do these safely? Jim

[dznf0g]

Originally Posted by Denis4x4

As the OP, I find it fascinating how this thread has morphed. I still think that manufacturers ignore the engineering and testing on vehicles other than SUV's and pickups simply because there is no profit motive.

That was the basis for the original thread.

And directly to your OP, I most respectfully, disagree...and the article, though simplistically and only briefly, indicates the most accurate synopsis of the process.

My personal professional experience and the article are pretty much in alignment.

[mstephens]

Originally Posted by zigzagguzzi

And number three should be does it do these safely? Jim

I think safety is just part of 1 and 2. If you can do all the maneuvers, that implies safety. If you don't break down, that implies safety.

The sensible analysis would be to have a road test for #1 that includes all the various maneuvers and then collect data for #2.

We have a lot of the data right here on this forum. I think SAE has defined a tow test, so why not run the TV through that and see what happens?

[rostam]

Times have changed. We are not in the 70's anymore and almost no one uses a sedan as TV. Car companies know this and have softened up the sedans to reduce the cost and increase the profit; they have no incentive to make "beefed up" TV sedans either, as the profit margin on trucks in already great. In my opinion, after market modifications cannot make sedans a viable tow vehicle either. No matter how good Andy is I cannot see how a modified sedan, rated to tow 1000#, can safely 6000#. Most people do a risk vs reward analysis and decide that using a modified sedan (designed to move passengers, with little margin put in by manufacturer) is not worth it as a TV. Customers want peace of mind not possible liability.

[cameront120]

Originally Posted by rostam

Times have changed. We are not in the 70's anymore and almost no one uses a sedan as TV. Car companies know this and have softened up the sedans to reduce the cost and increase the profit; they have no incentive to make "beefed up" TV sedans either, as the profit margin on trucks in already great. In my opinion, after market modifications cannot make sedans a viable tow vehicle either. No matter how good Andy is I cannot see how a modified sedan, rated to tow 1000#, can safely 6000#. Most people do a risk vs reward analysis and decide that using a modified sedan (designed to move passengers, with little margin put in by manufacturer) is not worth it as a TV. Customers want peace of mind not possible liability.

So, what's your experience in setting up vehicles and towing with them? In over 40 years of setting up vehicles for towing, Andy must be doing something right.

[Chuck]

Originally Posted by rostam

Customers want peace of mind not possible liability.

Sure, but that's a perception...not based on any facts. Its also a perception that cars are flimsy-er today than the 70's; the math says otherwise. They're bigger, heavier, and stronger(hp, torque) today.
But our perception is the opposite.
I see the oft-pictured chevy caprice pulling the airstream, and my brain says "big"...because thats the way I remember that car. I saw one in the parking lot the other day (rare site, these days), and it was dwarfed by the honda pilot parked next to it, and the mini-van (ha- "mini") on the other side of it.
The "mini" weighs 1000lbs more.
Likewise, I see a lot of these modern cross-overs, and they seem very small to me...until I stand right next to one. I think its because they're shaped kind of like the 2000lb hatch-backs of yore, and that shape triggers the "small" button in my brain.
I tow with a full-sized pickup truck, and nobody bats an eyelash at that, but the minivan has 50% more power in 1st gear than the truck. 50 more hp, and only a little less torque overall. The truck has to haul 1000lbs more of itself than the van does, and also has to punch a bigger hole in the air to do it.

[Stefrobrts]

Originally Posted by rostam

Times have changed. We are not in the 70's anymore and almost no one uses a sedan as TV.

But why not? Do they not use them because they are inferior, or do they not use them because they are not rated to tow. It's like a chicken & the egg thing. Are they not rated to tow because nobody tows with them, or does nobody tow with them because they are not rated to tow? We've all survived the SUV boom and people are getting back to driving normal sized cars. I just think recreational towing isn't even on the manufacturer's radar. They are looking at trucks as utility tow vehicles for landscapers and contractors, and RVs might as well use those as well.

There is no reason a big modern sedan cannot exceed the performance of the old tow vehicles, if the manufacturers expected them to be used that way. If you aren't living in your AS, and don't have a reason to buy a truck and put up with the terrible gas mileage of a big SUV, a sedan or mini-van makes a lot of sense for the still working, weekends only owner.

[MrUKToad]

Originally Posted by rostam

Times have changed. We are not in the 70's anymore and almost no one uses a sedan as TV. Car companies know this and have softened up the sedans to reduce the cost and increase the profit; they have no incentive to make "beefed up" TV sedans either, as the profit margin on trucks in already great. In my opinion, after market modifications cannot make sedans a viable tow vehicle either. No matter how good Andy is I cannot see how a modified sedan, rated to tow 1000#, can safely 6000#. Most people do a risk vs reward analysis and decide that using a modified sedan (designed to move passengers, with little margin put in by manufacturer) is not worth it as a TV. Customers want peace of mind not possible liability.

The point of the debate, though, was that the 1000lb quoted by the manufacturer as a tow rating had no bearing on what the car was actually capable of towing (safely, legally and all the rest). Sedan manufacturers know they're not competing in a TV market so just put an arbitrary and comfortingly low rating on their products because there's no money to be made by doing otherwise.

Whether or not you consider modern sedans smaller and lighter than their 1970s ancestors, by making some relatively minor modifications Can-Am has been able to show that various modern sedans (C300, Taurus SHO, etc) can tow successfully, regardless of the manufacturers' comfortably low tow rating. There are combinations out there now, towing safely and effectively; does that not demonstrate, at least in the non-truck and large SUV market, that tow ratings are meaningless?

[dznf0g]

Originally Posted by MrUKToad

The point of the debate, though, was that the 1000lb quoted by the manufacturer as a tow rating had no bearing on what the car was actually capable of towing (safely, legally and all the rest). Sedan manufacturers know they're not competing in a TV market so just put an arbitrary and comfortingly low rating on their products because there's no money to be made by doing otherwise.

Whether or not you consider modern sedans smaller and lighter than their 1970s ancestors, by making some relatively minor modifications Can-Am has been able to show that various modern sedans (C300, Taurus SHO, etc) can tow successfully, regardless of the manufacturers' comfortably low tow rating. There are combinations out there now, towing safely and effectively; does that not demonstrate, at least in the non-truck and large SUV market, that tow ratings are meaningless?

IMO, no.

[Bruce B]

Originally Posted by Chuck

.........but the minivan has 50% more power in 1st gear than the truck. 50 more hp, and only a little less torque overall.

I don't understand what you are referring to here. Are you saying your minivan engine makes more HP than your truck engine? Why refer to first gear?

Torque multiplies as a result of gearing. If you put 100 pounds feet torque into a transmission gear with a 10 to one reduction you now have 1000 pounds feet of torque. Now put that into your differential and multiply by that ratio. That engine torque becomes a big number....That is why different gear ratios make otherwise like vehicles feel so different. HP is HP, gear ratios have no impact on that, this has always been my understanding anyway...

Torque developed by an engine is just a small part of the equation. Torque curve and gearing play a very large part in the picture.

Just curious....
Bruce



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[mstephens]

Originally Posted by rostam

Times have changed. We are not in the 70's anymore and almost no one uses a sedan as TV. Car companies know this and have softened up the sedans to reduce the cost and increase the profit; they have no incentive to make "beefed up" TV sedans either, as the profit margin on trucks in already great. In my opinion, after market modifications cannot make sedans a viable tow vehicle either. No matter how good Andy is I cannot see how a modified sedan, rated to tow 1000#, can safely 6000#. Most people do a risk vs reward analysis and decide that using a modified sedan (designed to move passengers, with little margin put in by manufacturer) is not worth it as a TV. Customers want peace of mind not possible liability.

This is a theoretical argument. The fact is these cars ARE towing big trailers. Doesn't matter what one theorizes is not "beefy," or what tests one theorizes aren't done. There is a fact on the table: These cars DO tow big Airstream trailers. And, there are many of them. And they are not breaking axles and plowing into people. Hard to ignore the facts.

[dznf0g]

"many of them" and "facts" arent stats.

In order to settle this (and we won't because real data does not exist) one would need a collection of statistically significant samples carline by carline, with comparable groupings of towing mileages, of each carline. There would have to be equal groupings of those vehicles who exclusively tow within mfr limits and those who exceed mfr limits...by equally graduated amounts. I know of nowhere in the industry where this kind of data has been collected.

Anything less than that kind of empirical data is nothing more than cannon fodder. However, some of us live in that world (both inside knowledge of engineering and marketing practices and customer interface) and have experiences over decades which can offer educated opinions. But even that has no statistical absolute validity.