A Fool-Proof Method for Judging your Tow Vehicle

[Shrpram2]

I have had them all. I would definitely go with the dually. You can learn to drive it and the safety factor of the 4 rear wheels is worth the aggravation of the extra width

[Crbacsw]

I've been scouring the forums, reading varied opinions regarding towing capacity. Many with half ton trucks are pulling RVs with a dry weigh of nearly 9,000 lbs; some even bragging about being able to do so. Being able to tow it does not mean it is safe to tow it. Dodge rates my Ram 1500 Quad Cab at 10,000 lbs. towing capacity. That does not mean I can hitch up a 9k pound RV and take off for a cross country trip!

Determining safe towing capacity of a vehicle can be confusing. Polk's Towing Capacity Formula is an easy, reliable formula to determine SAFE towing capacity. Using his formula, I determined it was not safe for me to pull a 9,000 pound RV even though my 1/2 ton Hemi equipped Ram Quad Cab truck is at the top in its class for torque, power and towing capacity. According to Polk's Formula, I can safely tow a dry weight of under 7,000 lbs. That leaves plenty of room for storage, passengers, etc. without having to fret too much about exceeding the capacity. Just my 2 cents.

https://rvingwithmarkpolk.com/2012/0...wing-formulas/

[325BH]

Originally Posted by Crbacsw

I've been scouring the forums, reading varied opinions regarding towing capacity. Many with half ton trucks are pulling RVs with a dry weigh of nearly 9,000 lbs; some even bragging about being able to do so. Being able to tow it does not mean it is safe to tow it. Dodge rates my Ram 1500 Quad Cab at 10,000 lbs. towing capacity. That does not mean I can hitch up a 9k pound RV and take off for a cross country trip!



Determining safe towing capacity of a vehicle can be confusing. Polk's Towing Capacity Formula is an easy, reliable formula to determine SAFE towing capacity. Using his formula, I determined it was not safe for me to pull a 9,000 pound RV even though my 1/2 ton Hemi equipped Ram Quad Cab truck is at the top in its class for torque, power and towing capacity. According to Polk's Formula, I can safely tow a dry weight of under 7,000 lbs. That leaves plenty of room for storage, passengers, etc. without having to fret too much about exceeding the capacity. Just my 2 cents.



https://rvingwithmarkpolk.com/2012/0...wing-formulas/

It is actually quite easy: go to a scale and weigh your tow vehicle. Subtract GVWR from actual weight: that is how much you can carry.

To get more granular: subtract GAWR from actual axle weight. That is how much you can put on the axle.

Once you get close to one limit, you may be over on another. Just watch all of them.

Weigh, weigh, weigh. Easy peasy.

For some reason, people don't want to spend $10 to know the facts.

[Too Tall]

My formula is divide the OEM's tow rating by half. Just my opinion, I don't think you can have too much truck. Headwinds, grades etc...

[CaptnJohn]

1st is to check the number most likely to go over ~~ payload. Check the yellow sticker on the TV driver door pillar. A 9000# TT will have over 1000# on the hitch and a 5er 1650 or more.

[Crbacsw]

Originally Posted by Too Tall

My formula is divide the OEM's tow rating by half. Just my opinion, I don't think you can have too much truck. Headwinds, grades etc...

Your method is clearly a very safe thing to do. Based on my VIN, Dodge rates my truck at 10,000 pounds. Using Polks formula, I come up with a safe towing dry weight of 6400 pounds.

[Flybob]

Originally Posted by Crbacsw

Your method is clearly a very safe thing to do. Based on my VIN, Dodge rates my truck at 10,000 pounds. Using Polks formula, I come up with a safe towing dry weight of 6400 pounds.

Towing capacity and max load capacity are two very different things.

[Too Tall]

My general point is, IMO, MFG ratings are way too generous.

[CWSWine]

Originally Posted by Flybob

Towing capacity and max load capacity are two very different things.

Max Tow is GCWR -Minus- Truck ready to go camping = MAX Towing Capacity.

Max Payload is GVWR -Minus- Truck ready to go campng = Max Payload Capacity.

[tbln930]

Now the manufacturer's ratings are wrong? Come on folks quit giving bad advice on here.

[CWSWine]

Originally Posted by tbln930

Now the manufacturer's ratings are wrong? Come on folks quit giving bad advice on here.

Here is the place you can get the facts----

Matching Trucks to Trailers

Safety is critical when towing an RV Trailer. This training video discusses the importance of understanding a Truck's ratings and how these ratings limit the size of the trailer that can be safely towed. You will be provided the tools and basic understanding needed to assist your endeavor to properly match a truck and trailer, so that you can enjoy RVing safely.

[tbln930]

Good site for the newbie. In the end you have to weigh your rig together and the TV by itself and crunch your units specific numbers as painful as that might sound (it is not). These quick rule of thumbs and general guidelines are often misleading and mainly incorrect.

[Too Tall]

Originally Posted by tbln930

Now the manufacturer's ratings are wrong? Come on folks quit giving bad advice on here.

Trailer weight rating are a major marketing point. MFG's each had their own ways of determining how much weight their vehicles can tow, but there was no testing standard for all of them to follow. The SAE J2807 test is suppose to help standardize the test. But I think it's a suggestion not a requirement. The SAE test is all about how fast a truck will launch at given conditions. And maintaining a speed on a grade etc... It doesn't address wind resistance. Nothing about durability is another of my biggest want-to-knows. The SAE J2807 has only been around for about a year anyway. I guess one should ask the dealer if the truck meets SAE J2807, prepare for a blank stare. ha

[jjSpeedwagon]

I can't believe a lot of y'all referring to your pick ups as 1/2. 3/4 or 1 ton. That is old school when i was a kid and hasn't applied to any pick up built in more than 25 yrs.

[tbln930]

Exactly. Thanks. So much misinformation here. At least Ford 150, Ram 1500, gmc and Chevy 1500, are now rated to the J2807 standard. The F250 and F350 were not until the redesign in 2017.

[jjSpeedwagon]

Another thing that never mentioned about weight and balance then moving it down the road is static and dynamic weight. All placks on every vehicle, trailer or any other machine in our world with any kind of weight rating is STATIC weight. Then you put that static weight in motion it becomes dynamic weight. So when Cheverolet says u can put 3500k on your axial you sure can. But when you go down the road the situation changes I was a crane operator most my life I retired from the North Slope in Alaska. I ran 2 of the largest single boom cranes on the continent I am very familiar with static and dynamic weight and a lot of things I read on these forums about pick ups and trailer are misleading fo sho. My 2 cents

[tbln930]

The latest J2807 Tow Tests are pretty rigorous. Acceleration, grade, braking, steering (or rather the weight of the trailer tendency to steer the TV), and many other performance parameters are tested under towing loads. I went to direct to Ford's towing rep when I sized my truck. He pointed me to the J 2807 testing for the F150. After going through it all last spring I would say that Fords current (2014 and newer) F150 published towing numbers are pretty conservative. Too Tall is correct in that the marketing folks pretty much did the final specs before they started adhering to the current standard. Ironically, in many cases the trucks tested better than the marketing folks had been setting because of the fear of liability.

Here is an article on the testing process
SAE J2807 Tow Tests - The Standard

[rockfordroo]

Originally Posted by jjSpeedwagon

Another thing that never mentioned about weight and balance then moving it down the road is static and dynamic weight. All placks on every vehicle, trailer or any other machine in our world with any kind of weight rating is STATIC weight. Then you put that static weight in motion it becomes dynamic weight. So when Cheverolet says u can put 3500k on your axial you sure can. But when you go down the road the situation changes I was a crane operator most my life I retired from the North Slope in Alaska. I ran 2 of the largest single boom cranes on the continent I am very familiar with static and dynamic weight and a lot of things I read on these forums about pick ups and trailer are misleading fo sho. My 2 cents

Say what???

So you're telling us that the GM/Ford/Ram/Toyota engineers haven't taken into account the fact that the 3.5K (not 3500K I hope) on your axle is NOT moving down the road? You're right, the situation changes from static to dynamic, but to make us believe that the engineers don't account for that in their ratings is BS. It would make zero sense, and as Judge Judy says, "If it doesn't make sense, it's not true."

[jjSpeedwagon]

Originally Posted by rockfordroo

Say what???

So you're telling us that the GM/Ford/Ram/Toyota engineers haven't taken into account the fact that the 3.5K (not 3500K I hope) on your axle is NOT moving down the road? You're right, the situation changes from static to dynamic, but to make us believe that the engineers don't account for that in their ratings is BS. It would make zero sense, and as Judge Judy says, "If it doesn't make sense, it's not true."

What I said was that little plack on your pick up is a static weight rating for maximum weight for that pick up standing still. Not in motion. Rest is up to you I've never seen any engineer rating saying this chev pick up will pull 10k at 70mph no prob. Or any other speed.

[rockfordroo]

Originally Posted by jjSpeedwagon

What I said was that little plack on your pick up is a static weight rating for maximum weight for that pick up standing still. Not in motion. Rest is up to you I've never seen any engineer rating saying this chev pick up will pull 10k at 70mph no prob. Or any other speed.

I'm an engineer and I've done static and dynamic calculations. If you're telling me that the engineers don't design the vehicle brakes to handle the "dynamic weight" associated with the "static" weight that they put on their plaque (actually, in this case, it would be mass, speed and thus momentum and would concern the ability of the brakes to deal with the heat dissipation necessary to stop the vehicle a the GCWR - and moving at legal highway speeds), or design the frame, axles, etc to handle the "dynamic weight" at legal highway speeds, then I throw the BS flag.

What you're calling the "dynamic weight" is inherent in the static value they give you. They don't need to give you any "dynamic weight." The average vehicle owner would not know what to do with it. (Heck, half the people don't understand simple "weight.")

You don't see bridge limits that say "10 tons - but only 8 tons if you think you might hit a bump on the bridge."

As a crane operator, you may have to had to deal with something like "dynamic weight," (I'm guessing it has to do with the load swinging from the cable) but your average vehicle owner can't be expected to do that. It has to be built-in and it is.