xcntrk wrote:
Seattle Lion wrote:
I can't think of anything that would be gained by decomposing the sources of the various limits on our TV's. The manufacturers have an incentive to make these ratings as high as possible, since truck purchasers are looking for the best payload and tow capacities. I worry that the margins of error may be made too small in order to accommodate the marketing department.
I don't agree with what you're saying here. Sure I get manufactures are free to establish their own benchmark for tow ratings, and therefore free to inflate numbers as they desire.
Disagree...
Back to my earlier posts on this...decide either you believe in the
OEM's ratings or not. Also note that GCWR has an 'R' in there
If no, then do whatever, but know that you have taken the OEMs (yes
more than one) off the hook and taken that liability
If yes, then learn how that system works and goes to that picture posted
earlier
Both liability and warranty are baked into all ratings
Hopefully this will soon change starting in 2015 as Toyota, Ford, GM, and Chrysler begin aligning with the SAE International Standard J2807 (Performance Requirements for Determining Tow-Vehicle Gross Combination Weight Rating and Trailer Weight Rating).
But to your point above, deciphering your axle or total vehicle gross weight rating is very much a combination of the underlying component parts that make up that rating, with the lowest common denominator limiting the rating. Take my little 1/2 ton pickup for example:
- Rear Axle unit w/E-locker and 3.73 = 4800#
- Rear Springs = 4050#
- Rear wheels (20" 6-lug) = 4050# (2025ea)
- Rear Tires 275/55R20 (P-scorpion) = 4806# (2403ea)
The axle housing itself can support up to 4800# gross weight however the limiting components are the springs and wheels which hold back the rear GAWR to 4050# as a result.
Over analysis to lose the over all picture....a rat hole and need to
go back up to 60,000 feet to see the system
We will NEVER know which is the weak link dictating these ratings.
All we can do is guess
On that, a weak link can be a shorter MTBF that the EOM lowers to gain
more 'RATING'. They knowingly do that all the time and for folks out
here think pulled out of the sky...
My rear GAWR is 6,000 and is the OEM rating (GM), but GM purchases this
from AAM.
AAM rates this assembly they ship to GM at 10,000 GAWR.
Some see that the OEM tires are approx 3,000 rated each...so they assume
that is the limiting factor...maybe...maybe not...again we'll never
know
that kind of thinking would have them go out and purchase 5,000 lb
rated tires...but wait...how about the wheels? How about the brakes?
How about the springs? How about the bolts for those springs? How
about the frame hanger? How about the frame itself? and a BIG ETC...
Again, decide if you believe in the OEMs ratings or not...then the
liability issues when you re-engineer. Yes it is a multiple faceted
'SYSTEM' comprised of many systems and components
