Gdetrailer wrote:
4X4Dodger wrote:
TomG2 wrote:
4X4Dodger wrote:
....snip.......... And until this is done please do not continue to claim that a 3/4 ton truck is by default SAFER that a 1/2 ton or an SUV. There are too many factors involved.
You really think that a half ton pickup with a "Tow rating" of 9,600 pounds is good for that or more? Maybe I read it wrong, but you seem to be saying that the ratings are lowered by the engineers and lawyers?
Yes I do and that is **almost** exactly what I am saying. I said that the ACTUAL DESIGN LOAD is at least 1.5 times higher than the Design SPEC. And that the Design spec is further DE-RATED by the legal department to the numbers you see published so they can have what I called "legal Headroom" in case they must defend their decisions in court.
All over the world I have seen much smaller vehicles than 1/2 ton Pick ups carrying/towing much larger loads on a daily work basis than what most Americans believe is even possible. With much smaller engines. Are the physics different? No. It's the legal system that is different.
And further, as I pointed out previously, there has never been any real world testing of what the actual limits are for any given truck/spec combination. Until then the numbers are really meaningless.
4x4.. Are you a AUTOMOTIVE ENGINEER? Or just some backyard armchair engineer.. There IS a difference.. and I highly doubt that your are the first type of engineer I mentioned..
Reason being is if you truly were a AUTOMOTIVE ENGINEER you would would be under a NON-DISCLOSURE/NO COMPETE clause as terms of your employment and would not ever be able to release this kind of info on a public forum..
Manufacturers DO NOT "over engineer" things now days, if that was the case then every single wire and hose on our vehicles would be EXACTLY 1.5 TIMES LONGER THAN NEEDED..
They are not, in fact I often wonder just how in the world did they get that wire to stretch the extra 1 or 2 mmm in order to plug it in..
As a backyard mechanic with a lot of years of repairing my own vehicles I CAN ASSURE YOU that there is no truth to the 1.5 TIMES over engineering of any vehicle I have ever had..
The specs that are officially released is the max the the MANUFACTURER is WILLING TO GUARANTEE.. That is because the vehicle is only as strong as the WEAKEST PART..
Without CLEAR KNOWLEDGE OF WHAT the weakest part is your are simply GUESSING.
Guess wrong and YOU are now on the hook if anything goes wrong..
I personally don't care to "rely" on your 1.5 times heavier than needed statement.. Instead I would follow the folks who designed and built the vehicle recommendations which are pretty clearly spelled out on the tire loading sticker now days.
I OWNED a heavy half years ago.. It ate suspension parts and brakes, I had fully rebuilt the front end by the time I had 50,000 miles on it.. It needed rebulit the second time by the time I traded it at 140,000 miles for a F250.. Brakes.. Yeah I could count on new brakes all around at 40,000 like a clock..
That F250 I STILL have with 200,000 miles on the clock only needed ball joints at 120,000 miles and has all the original tie rod ends..
Brakes, yeah the F250 is easy on them, changed the fronts after only 90,000 miles and the rears after 120,000 miles..
That is driving the same roads hauling the same loads as the heavy half..
So much for your 1.5 times over engineered..
Well while your backyard experience with cars is valuable as mine is and nobody is asking you to rely on it..you may do as you wish.
However the 1.5 times safety factor for critical design elements is standard practice and it's often exceeded. For NASA manned spacecraft it was a whopping 5 times. We often told NASA we cant get those kinds of payloads up if thats the rule...And I have done a fair amount of engineering as that was my job for many years. I have designed floors for Boeing Aircraft, Payload separation for a private launch vehicle, motor separation for that same vehicle and payload capacity, When I was very young I was part of a team that designed the first Fluke hand held Multi Meter plastic casing and packaging (the elelctronics not the box ie fitting all the electronics in the new case) For IBM in Manassas Va I designed water cooling systems for Nuclear Submarine Electronics, I could go on and on but I think you get the point.
And yes critical systems that could be deemed to be SAFETY related are definitely designed with a good safety factor. Admittedly this does not apply to the same degree to your radiator hose but it does to many systems. However even your lowly radiator hose as a Design that allows it to exceed any temperature your car is likely to generate.
In any case I can assure you I have spent more time than you could ever guess in meetings where this exact same discussion took place about any number of products, with the lawyers, engineers and management all trying to find the right balance between SAFETY,COST, LEGAL PROTECTION, and very often WEIGHT.
So I think that I do indeed speak from some level of experience. And the part you dont know, and neither do I, is exactly HOW BIG that safety factor is in these trucks...because neither you nor I have seen the Drawings, the Engineering Specs and been present at the meetings. But I can assure you there is one and the Minimum is traditionally been 1.5 and is often greater depending on the part.
Now you are right about one thing. (more or less) before the advent of computers and relatively easy application of FEA (Finite Element Analysis) often times things were made much heavier than they needed to be. Steel was cheap, Labor was not too expensive and so often that is why you ended up with a Hudson President that was more like a tank than a car. Now days FEA is applied to critical parts to make them lighter and cheaper by strengthening the areas that need it and lightening those that dont. This has led to ever lighter, SAFER and more fuel efficient cars.
But dont fool yourself: You can bet money on it that if the design spec called for a bolt of a certain strength on your Wheel Hubs then that bolt was "upped" at least by a factor of 1.5 more likely 2 in terms of its strength to resist either shear or tension.
