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RE: GM's new 2013 tow ratings
The test(s) are good bench marks to a degree. BUT, IIRC the spec, the max frontal area for the DOT class HD2 and 35 series rigs, ie over 8401-13500 or so, is 80#. So If I was pulling my old TT at 90#, how much would I need to derate the rating they gave my truck or ANY truck? Are they going to do as I saw a poster from Ford back in 92 or so in an RV dealership.....
Ie at the time the max for most 25/35 series trucks with BB8 and the non turbo diesels out was 10K lbs, this was at up to 80#. If you had 81-100#, you had to reduce the tow rating by 2500 to 7500 lbs, if 101-120#, you were down to 5K max, and if over 120#, if was not recommended you tow with you F series truck!
The Ranger and Aerostar with the 4.0 V6 IIRC went something to the effect of 5K max up to 60#, 61-70# was 4000, 71-80# was 3000, and over 81# was not recommended you tow with these rigs.
Then, most will on here will recomend one get TT's especially with smaller motored rigs with the aluminum siding that is 300-600 or so lbs lighter than the smooth solid fiberglass walled rigs. Granted cheaper too. BUT, reality is, the Heavier fiberglass rigs tow easier! yep, good old lack of aerodynamics of the aluminum, screwing up the air flow, so at the end of the day, you get worst MPG with an aluminum sided trailer, need more HP, probably NOT make the SAE spec, when you should have gone with the heavier trailer!!!!!
So, how many of you have I screwed up yet? reality is, yeah I may seem rather liberal with my what is legal vs not at times, but reality is, I'm probably way more conservative than you think. I have no issues telling folks, if you are at max gvwr, no matter how it is figured, you have no room for HW of a trailer, so you can have a saturn 5 rocket motor in your tow rig, reality is, your ability to tow is SQUAT, NADA, ZILCH! Every lb you add to the TV is not a lb lost in tow rating, try more like 10lb of trailer! as you need to carry 10 percent of the wt of the trailer on the tow rig! So if you want to pull a 10K trailer, you better have 1000 lbs minimum of payload, or upwards of 2500 if you need 25% for a 5w or equal!
Along with the, if someone is hit at 18K lbs at 50 mph in a t-bone fashion, does not matter who's fault etc, does it matter if the 18K rig with a trailer is over, at or under the tow rating or gcwr, but below ALL the axle ratings? no it does not, as someone is still dead! not more dead with the SB8 vs dead with the BB8 or less dead with the TD! Dead is dead!
Marty
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blt2ski
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05/24/12 12:17am |
Tow Vehicles
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RE: GM's new 2013 tow ratings
The new standards do give folks a "BASE" for lack of better term to see how the rigs work....
So until the SAE specs start to include max grade I can pull, frontal area figures for max tow ratings, aerodynamics of the towed rig in the ratings, even different types of tires can effect the how much HP one needs, while better than before, still a LONG way to go when you compare Light duty towing drivetrain specs to specing an MDT/HDT rig, ALL of these go into figuring out if a rig will or will not work for the end user.
There is a LONG way to go before SAE will gain ANY trust in the tow ratings from my standpoint.
Marty
This post need to go on a sticky called interpreting SAE Towing specs.
Are you saying the part you have taken from my slight book? or the whole thing? Then along with it, I can pull a few formula's out of some spec books I have the show how larger rigs are speced, powered too, geared too, how the gearing is done via tire diam, max rpm of the motor,.............Then one needs to figure out the drivetrain loss due to AC, alternator(s), type of ground one is driving over.......
These new specs give folks a base, but at the end of the day, if "YOUR" needs are different than the Engineers that got together to make the spec......these specs may or may not be up to "YOUR performance standards". And as one of my fellow mods likes to say sometimes, "performance" is subjective! For me pulling a 5 percent hill at 45-50 may be fine, if a long straight shot, others will be screaming bloody murder if they are not going at least 65, so now one is into tuning, trying to up the HP needed........blowing things up......anyway.
By the way folks, IIRC one of the specs, min speed of 35mph up a 5 percent grade with AC on in 100F heat or some such thing........many states the minimum speed on some jurisdictions interstate hwy's is 40 mph. So the spec is specing a speed that at the end of the day is illegal in many jurisdictions! Altho in those, if that is the only road you can take, the LEO's look the other way if you are in the appropriate slow vehicle pulling lane. Others, BC is one, signs on the interstate equal say if you can not go up the hill at 40 mph or some such number, you must use one of the non interstate type roads, or be fined staying on the interstate!
You may be able to pass these J8207 performance specs, but at the end of the day, it still may not get you to your destination! As I have found a few times, a semi that pulled an 80K load of furniture from New Orleans to near me here in Seattle at 60 mph on the interstates thru the Rockies etc, only to not make it up a local side road 1/2 mile from the home the driver was to deliver too!
Marty
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blt2ski
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05/23/12 11:22pm |
Tow Vehicles
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RE: GM's new 2013 tow ratings
While I probably appear to be one of the more liberal at times when it comes to ratings, ask yourself this. How many times have I said if you have 1000 lbs of payload, assuming the rating to tow if one will, You have 10K lbs of trailer using 10percent HW, and a whopping 4000 lbs of trailer capacity using 25 percent HW. Reality is, engine, axel ratio etc is NOT the only factor in trailer capacity, but payload ultimately is an enemy!
I also doubt that doing most of the tests, ie braking and handling ones, that a bigger motor/lower axel ratio will allow one to stop, nor go around corners faster etc. Smaller motored/lower axel rigs will roll a given trailer in a given circumstance, "the same" as a higher rated rig! If you load a rig unbalanced to say the right side, go around a left turn too fast, you're going over no matter if under or over a tow rating!
I have on the other hand, stalled rigs out, seen rigs stalled out due to lack of gearing from going up steeper hills. I've seen a rig with a GCWR LOWER than it GVWR go up a hill at 150 percent of GVWR pulling a trailer, meanwhile a rig with a 16K GCW could not pull the hill at 12K, like the other rig weighed! One was a 292I6, the other a BB454! In fact, the 292 went back to the bottom of the hill, we put a chain on it, pulled the R3500 with the almighty 454, TH400 and 4.10 gears UP the blinking hill! From that day on in about 1990, I learned NEVER trust tow ratings per say! I have not followed them since, nor will I with these new standards.
The new standards do give folks a "BASE" for lack of better term to see how the rigs work.....but when you consider a 25K rig and a 15K rig, ea with different frontal area's need 135HP to go 60 mph down a freeway, one can see that frontal area is more important than wt at times too. A 5K rig with 90# of frontal area, typical RV size, needs 135HP, as does a 25K rig with 70#. At the end of the day, you change out trailers from a non slide to a slide, the slide may only weight 2000 lbs more, but reality is, it is more like a 5K lb difference, with the other 3K coming in the additional 8-10# of frontal area that most slide trailers have over a non-slide. For ea additional 3# of frontal area you add to a rig, that is about equal to 1000# inside the box you had already!
Semis hp needs can change over 30percent from a base 18wheeler you see. A rig with a full aero pkg, needs 30 percent less, haul a cattle or car hauler, and you need upwards of 30percent MORE HP than a basic 18wheeler at the same overall weight.
So until the SAE specs start to include max grade I can pull, frontal area figures for max tow ratings, aerodynamics of the towed rig in the ratings, even different types of tires can effect the how much HP one needs, while better than before, still a LONG way to go when you compare Light duty towing drivetrain specs to specing an MDT/HDT rig, ALL of these go into figuring out if a rig will or will not work for the end user.
There is a LONG way to go before SAE will gain ANY trust in the tow ratings from my standpoint. As I've also said in the past, my dmax does not meet my minimum tow spec, and need to derate it to pull my equipment trailer to job sites. Almsot 5-6000 lbs derated mind you. Meanwhile my old 6.5 td, I could up rate it over 8K lbs and still get to a job site! The 454 downrated to less than GVWR, the 292 I could go over double the gvwr and get to a job site! Hence also why, my BEST tow rigs have been correct gvwr to payload needs, with smaller motors, correct trans gear ratios and axle ratios to tire diam. The monster tow rated rigs have been POJ!
Marty
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blt2ski
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05/23/12 07:52am |
Tow Vehicles
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RE: 3rd vehicle strictly for towing? Need advice.
11 yds of sand is 33K lbs just in and of itself, topsoil is usually a ton or so per yd, sometimes more.........That PJ was getting pushed to its limits more than likely!:B
Marty
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blt2ski
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05/22/12 11:48pm |
Tow Vehicles
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RE: Maximum I can tow safely with this truck
At the end of the day, there will not be a simple answer! Just what one wanted to know eh!
If you are at max gvwr before hooking up a trailer, you tow capacity is ZILCH, ZIP, NADA, NOTHING!
If you have say 1000 lbs left before hitting GVWR, then divide the 1000 by the hitch wt you need. if 10 percent, 1000/.10 = 10,000 lbs of trailer. If you want and need 25 percent, then 1000/.25 = 4000 lbs!
If you personally want the ability to go from 0-60 in 10 secs at 15K lbs, then figure out how many ponies, gear reduction etc you will need to do this. Reality is, way the heck more HP than you have! or will have for that matter...
If you want to pull a 30 percent grade at 20K lbs total, your truck has 375 lb ft of torque, you had better have an overall gear ratio reduction of around 24-1 with 31" tires. 29-1 will net you 35 percent before stalling out.
Safe is also a matter of what is safe stand for. if it is a non swaying trailer, well, that is up to how the owner/operator of the trailer loads it. If more than 500 lbs difference between the two side occur, chances are high it will sway, along with being illegal in many jurisdictions. If you have too little hitchwt, it will also potentially sway, be you under a manufacture gcwr/tow rating or not! Some of us can set up trailers to be perfectly no white knuckle driving etc over the tow ratings. Others can not even get an UNDER tow rating setup to pull safe, sane and straight! Rigs with trailers moving more than 12" side to side, while unsafe, also illegal!
I personally will not tow a trailer that is more than 2x the GRAWR of a given tow rig. So if your rear axel is rated to say 4000 lbs, the max trailer I would pull is 8000 lbs, I do not care that ford rates the thing at 11000 lbs.
Another rule of thumb if you will to look at. Not saying I agree, but something to think about. Max trailer length of 20' for a 110" wheel base rig. Then for every additional 4", you add a foot to the trailer length. Then of course the ggroup or person that started this little rule, says do not pull a trailer if the wb is LESS than 110". I personally say BS to that, so for ea 4" LES WB you have, reduce the length of trailer by a foot! To me this rule should go both ways. If pulling a 5W, you can probably go a bit longer. If you have a LONG rear overhang, shorten up the length some, if less than say 4-5' of overhang, pretty typical of most rigs, then you can go a bit longer, hence why 5w's could go probably 3' or so longer! and still be fine. If you have an 8 lug SW 25 or 35 series truck, you can go a bit longer than a typical 15 series truck too. A dually longer yet! From the above where I say BS to the less wb part, all of this is my personal opinion on how to use this rule of thumb!
Have I confused you enough? probably, but you will figure out what will or will not work.
marty
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blt2ski
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05/21/12 08:33pm |
Tow Vehicles
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RE: Doolie Conversion?
Your current truck setup will weigh from about 6500-7000 lbs depending upon the interior options. My 05 dually with a mid level trim is 7300, another fellow with a 4x2 and low end interior is 7200, another yet with an LT interior is 7600.
I have aprox 2900-3000 lbs empty rear tare, front is typically 4500-4600 empty tare.
If you want dually rims on the front, you will also need the extenders that bolt to the SW hubs. Rear dually's also have additional springs than a SW, along with the wider axel as mentioned why.
As far as legality goes.......that is between you and WV as far as licensing goes. Right now in the state of Washington, I could legally go down the road with your rig at around 20K gvwr, pull ANY trailer up to about 73K lbs with correct paid for gvwr tags.....with a dually I could get to 32K lbs gvwr, also around 73K lbs of trailer with out too may issues......issues per say.....
Marty
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blt2ski
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05/21/12 07:57am |
Tow Vehicles
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RE: Would you tow with this veichle?
Going back to will a liberty tow a trailer? yes it will.
Surge brakes work as do electric. Surge brakes generally speaking need the TV to be heavier than the trailer to work, along with the TV's brakes doing the initial braking. There is no way to manually from the driving position to activate the brakes as one can do with electric brakes. having used both, both work, but do prefer electric vs the surge brakes. Surge brakes are better than nothing!
Also, last I looked, J2807 is not a law, only a general recommendation as to what new manufactures should meet for "performance" specs. At the end of the day, it is up to the individual jurisdiction that you travel in and thru that will decide "what" performance you need and how they will test as to "IF" you make "spec" on their roads. Some of the J2807 speed specs would be too slow on some states and at lest one canadian provence minimum freeway road speed. So just because you meet the J2807 spec, does not mean you are legal! Nor does it mean you will be able to move your rig in all situations. You may find yourself stalled out on a 30 percent grade, while the J2807 spec only tests that you can go up a 12percent grade. About half of what I go up in downtown Seattle on some grades on a daily basis. Which means, for my useage, the J2807 spec is not tough enough! and will be useless to determine if a given tow rig will meet "my" spec from an end user standpoint.
Marty
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blt2ski
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05/21/12 07:23am |
Tow Vehicles
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RE: Doolie Conversion?
600 lbs of aluminum flatbed is STILL heavier than a reg box at 350 or so lbs! So going with a flatbed as I said before, will not net you squat, if you are hoping to gain payload. If you compare an aluminum to a wood deck steel frame bed......at 125 lbs per lin foot, vs the aluminum at around 70-80 lbs a foot, yes you gain some payload, lower the tare etc.
Not sure how you come up with a 16700 legal tow rating as of now vs a dually at how much? but reality is, you could probably tow the bigger trailer with what you have legally. At least where I am, manufacture gcwr/tow ratings mean squat, so if the limit is current net payload divided by .25 for max trailer, then I can buy it, otherwise, you can pretty much pull what you want as long as the axels of the tow rig and the trailer meet the max load per the jurisdiction you are in.
As far as rear capacity goes, yeah, you can get from about 6500-7000 lbs on the rear, to upwards of 12K if you go with dual 16 or 17" sizes. along with upgrading the springs etc.
Marty
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blt2ski
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05/20/12 10:15pm |
Tow Vehicles
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RE: Doolie Conversion?
Most aluminum flatbed/utility bodies are still heavier than the fiberglass standard pickup bodies. Reality is, you will still be heavier in the end with a aluminum body.
As far as gvwr goes, some say you can not change the door sticker, others know better, ie if you find the right body manufacture, chassis upfitter, they CAN and will change the gvwr if approriate items are added etc.
Reality is, you will lose some performance with a dually, as you will be turning more tires and wt ie additional drivetrain loss. The only thing you will gain, is potentially the payload part of the equation, which it sounds like you want. You could also go to some 19.5 SW tires, and potentially not have the amount of drive train loss as duals would do, and still have more payload at the end of the day!
marty
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blt2ski
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05/20/12 06:57pm |
Tow Vehicles
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RE: 3rd vehicle strictly for towing? Need advice.
I would try and find a 4.10 rear if you get the 4 sp auto, if a 6 sp auto, ie probably less than 3 yrs old, do not worry about the ratio.
Engine wise. 96+ GM motors, the Vortec 350/5.7, 6.0, 7.4, 8.1 gas all frankly will do the trick. The 350 will be the slowest up hills, the 8.1 potentially the fastest and most reserve HP, along with being the thirstiest! The 7.4 or 6.0 motors, should be pretty equal in performance. The 5.7 and 7.4 will be about 01'ish and older, the 6.0 and 8.1 versions will be the newest most recent body style. The 6sp auto will only be behind a 6.0 gas, which frankly, is producing HP/torque ratings on par or better than an 8.1, with better mpgs, so really no reason for some yrs to worry about the 6.0 vs 8.1 motor differences. With Ford and say in an Excursion, then the V10 or 7.3 diesel motors would be my first choices. I would personally stay away from a 5.4 v8, or a 6.0 diesel. Vans or crew cab pickups with either Ford or GM, Motor choices would stay the same. Not sure I would go with a dodge, as they did not have a true crew cab pickup until the lst few yrs, and the vans were sprinters, which are not "bad" vans, but not a lot of power to them, they would do the trick but be on the slow side. Along with pretty good MPG's, I've been getting 20 mpg on the freeway with one at work.
mileage wise, depending upon budget, I would stick to less than 150K if I could find one. 270K is a lot! You'll be spending what savings you had over a rig at 10K in repairs, potentially a new motor, tranny etc. if those items have not been replaced.
As said before, just about ANY 8 lug rig will be better than a 5 or 6 lug rig, any brand etc.
Marty
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blt2ski
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05/20/12 06:06pm |
Tow Vehicles
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RE: Did I choose the wrong gear ratio 3.73?
Torque is multipliable. HP is not.
Old 4sp auto with 4.10's, at 20Klbs, one could go up a 20 percent grade before stalling
6sp with 3.73 = 30 percent, 4.10's = 35 percent
While a RA ratio change works from an initial. One also has to look at pk hp rpm at a given speed in relation to the tire diam. In my old truck, 3.73's would have been better, when I pulled at 2500 rpm on a hill with 4.10's, I was going 35-38 with 4.10's, 3.73s would have netted me about 3-4 mph faster. Assuming gear below direct, direct was 50 vs 53. Sometimes the taller ratio is better, Others, lower is better. Alot will also depend upon the gear split ratio of a given tranny too.
With an upper 300 ponies available, this rig be it a 3.73 or 4.1 will not care. The 3.73 would be the best for on that is commuting more in the 65-70 range on a freeway, if towing/commuting day in and out as I do with work at speeds under 60, then 4.10's would be better.
Marty
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blt2ski
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05/20/12 10:42am |
Tow Vehicles
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RE: 3rd vehicle strictly for towing? Need advice.
Sorry, I would be like Donn, NO WAY would I look at a 1500 burb for towing with a family of 5. It would not work for my family of 6, with a dog the size you have, on par base wt wise as my family of 6. When the 4 kids were adult sized teens, we were in the 1200-1300 lbs range, putting a 1500 burb at gvwr before hooking up a trailer, then adding in the 700 or so lbs of HW.
Look STRICTLY at 8 lug 25 or 35 series vehicles. Be it a Van, cheaper than burbs by a LOT, a burb, short box crew cab pickup. The GM 1500HD might work well, yeah badged a 15 series, but a WOLF is sheeps clothing. Do not look at ext cab pickups, your kids may out grow the back seat way sooner than you think!
Marty
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blt2ski
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05/20/12 10:05am |
Tow Vehicles
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RE: Did I choose the wrong gear ratio 3.73?
Actually, the 6sp 3.73 is not just a bit better in 1st gear from an overall low standpoint, it is a LOT lower. The 1st gear with a 4sp auto is 2.48, 4.1 for the 6sp. You could be as high an RA as 2.48 and still be lower starting wise than the 4 sp. Last I checked a 15.2 for you combo low end was WAY lower than the 10.168 of the 4 sp. Plus as mentioned, you have a double od at.64 or .61, so better mpg's.......I'd have no issues pulling upwards of 12K with your combo. More if you had a SW or dually 3500.
Marty
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blt2ski
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05/20/12 09:13am |
Tow Vehicles
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RE: Need tires soon; looking for opinions on
I'd buy them. Then again, I've had some 50-60 cooper tires over the last 3 decades, NONE have blown up, can't say the same for GY and Michelin, Tires last as long as the more expensive ones, but cost less.
My 02
Marty
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blt2ski
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05/19/12 11:18am |
Tow Vehicles
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RE: Would you push it?
yes.
Assuming brakes on the trailer, proper hitch rating etc. I'd probably even take in the freeway assuming all the axels are with in spec!
Marty
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blt2ski
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05/18/12 09:55pm |
Towing
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RE: Ok here we go
Didn't you know you need a Kenworth to tow that lawnmower trailer! geez, some people! what is the matter with them. Then you need a saturn 5 rocket to tow the kenworth, since the kenworth "might" have a hard time with that 1000 lbs trailer at best...........
Marty
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blt2ski
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05/17/12 08:38pm |
Tow Vehicles
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RE: TV Tire Selection
The one that I feel is important, is tread design. Some if the past have pushed Michelin XPS ribs as long lasting tires. That is great if you live in the desert SW an do not drive in snow/ice/mud etc. Then these are the last thing you want on your truck, unless for me anyhow, they might be a summer tire in the NW. Then I would switch to a traction tire for when it rains, snows etc.
Load capacity is good, one thing to remember, P tires payloads are supposed to be reduced by 9% when used in towing/truck hauling situations. Hence why many will say go to an LT C, D or E rated tire. For you, I would go no more than a C if you have a choice between the 3. An E rated tire will typically carry 3000 lbs per, D might be 2600 and a C 2200. As long as the two tires on the rear meat you RA limit, probably 3500-4000 or so lbs, you're good. You really do not "need" E rated tires giving you 12K lbs of capacity. if you loaded them up to 80 lbs, you ride would be rough, you probably would not even have full contact patch of the tread width happening. I've had that happen on a 2500 and my dually on the rear when running empty. Why buy an E rated tire that is able to handle a 3K load at 80 lb, when you only run 2000 lbs and 50 lbs when an LR C will do 2200 at 50 lbs.
Brands, my favorite is Cooper, Toyo, last generally speaking is the Big M, too much money for what you get mileage wise, BFG is not too far behind generally speaking also.
Marty
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blt2ski
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05/17/12 07:55am |
Tow Vehicles
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RE: truck tag
Mitch,
One thing you need to remember about how OUR weight laws work. for that mater how ALL 50 states weight laws work. "TRUE" weight laws protect the road/bridge structures, IE damage from rigs over 20K per axel, 500 or 600 lbs per inch width of tire, 34K per tandem etc. From an engineer standpoint, or some other factor, the safety of the road, keeping bridges from collasping etc. That is what the "weight" laws protect.
The other laws that will get you off the road, are the fmvss or equal laws. with out quoting one direct, as an example, if you load you F150 to say 19K lbs gvw, 9500 per axel with at least a 10" tire, be them tires a P, LT or truck rated tire, the LEO looks at a chart that says something to the effect of a 15K-20K rigs, you might be asked to accelerate to 10 or 20 mph on the road, then stop with in say 150'. If you stop with in 150', you're legal, If it is an inch over 150', you're parked on the side of the road with a "failed" brake system. A rig from 10-15K might have to stop in say 140', under 10K 130'. Yeah these laws refer to wts, so some think they are "weight laws" but they are not "true" wt laws!
These FMVSS laws are the ones that will get true "unsafe" rigs off the hwy, not wt laws. In fact, in the Federal bridge law, it states an over wt rig per say, can not be kept from continuing in some cases. Keeping commerce going is the goal, collecting the appropriate tax/money for the damage you are doing to the road beds so when repairs are needed, there is money to replace locally, 520, the deck on I 5 etc.
This is how our state works, this is also how the other 49 states are supposed to work too! If a state limits you axel wt to something less, then federal funds for roads could be with held, OUR RCW's state, that one gets the max per this law, such that fed road funds will not be with held. with that as my example above shows, a dangerous rig WILL be gotten off the road! more than likely, not due to a wt law!
Marty
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blt2ski
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05/17/12 07:17am |
Towing
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RE: How can this be?
by the way Bill, even if you did stop in an OPEN scale. the chances of you getting hit for an overwt would be slim in some states, very slim to none in most. If you are like most on here, under a factory axel rating, you will 99.9+ percent chance of not getting a ticket, unless, you have a really low paid for plate, if your wt tag if you have to buy one, is above what you weigh, then your chance is really slim. If you are in Wa st, unless your duals are over 20K lbs, 11-12K or so on any of the single tire axels.....your chance of an overwt ticket is NONE, NADA, NOT HAPPENING!
But it is BEST to stay out of open scale houses if you are a private RV.
Marty
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blt2ski
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05/16/12 10:53pm |
Tow Vehicles
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RE: How can this be?
YES, you can stop at the DOT scales at the side of the road when closed, you can weigh yourself axel by axel. I've even stopped there a few times playing with my WD setup, to see how much I was pulling off the FA wehn in a DW mode vs 1, 2, 3 or 4 even 5 chain links was putting BACK to the FA, then used the appropriate links to put back on the FA what was lost when the trailer was hooked up.
If you know your base wts, when you drive thur, if there is a scale screen 100' in front of you, you can slooooooowly drive thru, ie 1-3mph and you know what your weigh at that time vs base amount.
Marty
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blt2ski
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05/16/12 06:19pm |
Tow Vehicles
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