What's Your Margin?

Throughout the years, I've heard a hundred different schools of thought when it comes to towing capacity vs. what someone should actually haul.  75% of capacity, load it up all the way to the number on the sticker, haul at least 1000 lbs. below to tow rating etc. etc. etc.

When I bought my truck, I went with something that could haul at least 7000 lbs, so I could haul a 5000 lb. car and trailer combo.

So, what do you use as your rule of thumb?  

Mine changes based on a lot of things. I would say primarily it's distance. I feel alright towing at the limit if I am just going a short distance but boy is margin helpful when you are towing a few hundred miles. Also how much does the load vary? If you tow one combination all the time you can spend the time and get the balance right which allows you to be at the edge safer. 

Yep. Mine varies depending on distance and speed.

35 mph for 5 miles, well over 100%.

100 miles of interstate, 90-95%.

The margin is already built into the rated capacity. Meaning you can likely tow more than the rated capacity safely, but the lawyers want a larger margin for liability. I think that correct tire pressures on tow vehicle, and trailer, properly distributed weight, cargo, and tongue loading are most important.

Remember that the way capacity is rated has changed a ton over the years, significantly once SAE Jwhstever was adopted that includes power as part of the rating.

Depends on the vehicle. Our previous tow vehicle f150 is rated I think 11k and change, but I can't imagine that towing much more than about 8k of enclosed trailer would be a positive experience. On the other hand, the class A RV just doesn't care. If you believe ford's chassis ratings we're technically exceeding it's tow capacity by almost 50% and the difference between trailer and no trailer is barely noticeable. Likewise the previous-previous tow vehicle was a 3/4 ton dodge rated about the same as the f150 but it towed the same trailer with less tongue weight better, without any chassis upgrades like the airbags that we put on the f150.

Having towed a lot of different loads with a lot of different vehicles ranging from a few 100 pounds to 140,000 pounds, I would say the practical limit is fairly obvious after a short drive, and may have no relationship with the factory tow rating. Some vehicles make you clench up doing well below their rated maximum, and some vehicles are stable and turn and brake well despite being at the limits of their capacity. When I pass someone on the highway pulling what appears to be a large load I often look over to see the driver's demeanor. Sometimes they are hunched over the wheel with both hands gripping tightly making constant adjustments and I know they are in over their heads. But sometimes you go buy a newer pickup pulling a massive tri-axle fifth wheel and the driver will be casually slouched back with one hand or a few fingers on the wheel and you know that he is having a much better towing experience despite pulling a lot of weight. We rented a 2800 pound tandem axle bumper pull to go camping a few weeks ago and my 2022 Jeep Grand Cherokee with a tow rating of 6800 pounds was not very happy. I stopped to crank up the weight distribution bars several times but it did not really help. I stayed well under the limit the whole way. My 2006 Land Rover LR3 on the other hand has pulled far heavier trailers with no drama at all. 

I've never thought about it. I've almost always had plenty of tow rig. I've towed the same trailer/load behind a GMT400 3/4ton, GMT800 1/2ton and E450 22passenger. The GMT800 needed a brake controller. The GMT400 needed a better steering box. The E450 was like nothing was behind it. A big heavy rig just doesn't feel the weight as much so that's more my preference.

My other good data point, towing my E36 behind my dad's 2020 Fiso is lovely. What it lacks in weight it makes up for being a fresh modern truck.

There are 2 numbers for capacity, payload and tow.  My rig is a travel trailer, so air drag is a factor too.  My comfort factor is about 75% on payload and tow, even with that a 1500 silverado with the 4.8 and 170k miles the motor is working hard in the hills.  But otherwise it seems to work OK.  First pull was with a colorado, more like 90% there and after one drive the truck got sold.

In reply to dps214 :

I'm with you on this.  I've owned several 1/2 tons and a couple 3/4 and 1 tons, and the difference is night and day.  We've pulled up to ~12,000 lbs with our F250 and F350.  They knew the load was back there, but it never felt nervous.  The 1/2 ton trucks got shook up way easier pulling much lighter trailers.  I can't pretend to know exactly why that is the case, but it has been noticeable.

Similar to what others have said, my 1500s have always felt good up to maybe 75-80% of what they're rated for, and even then the suspension is usually really wallowy. I don't feel like the power is necessarily all that different if you've got a small block gas engine in a 3/4 ton truck, but the heavier duty transmissions do seem to take abuse better and have somewhat better mapping for heavy loads. I wouldn't hesitate to tow 100% of the rated capacity with the Suburban if the weight distribution is good. That relaxation factor is huge on those long haul drives; I didn't realize how much it wore me out chasing a 1500 across the road for hours on end.

In reply to buzzboy :

Fiso?

I lost the towing arguments years ago to Alfadriver but I still stand firm on wheelbase is king for tow vehicles. 

I'll gladly jump in my 2.7T Silverado or Dads F350 6.7D and toss a trailer and car on it but the F350s 8 foot bed and wheelbase makes the same trailer feel like it's not even there.

gearheadE30 said:

Similar to what others have said, my 1500s have always felt good up to maybe 75-80% of what they're rated for, and even then the suspension is usually really wallowy. I don't feel like the power is necessarily all that different if you've got a small block gas engine in a 3/4 ton truck, but the heavier duty transmissions do seem to take abuse better and have somewhat better mapping for heavy loads. I wouldn't hesitate to tow 100% of the rated capacity with the Suburban if the weight distribution is good. That relaxation factor is huge on those long haul drives; I didn't realize how much it wore me out chasing a 1500 across the road for hours on end.

Best thing I did for my 1500 was put 2500 leaf springs in.  They got rid of all the wiggle, made towing much calmer.  

In reply to Jesse Ransom :

F150 ~ FISO

In reply to buzzboy :

Ah...

Between that and the OBS stuff, I'm amazed at how much ambiguity can be introduced to talking about one of the most common vehicles on the planet.

One of the big things that makes a difference is your tires.  Light truck 4 ply?  Load D 8 ply?  Load E 10 ply?  This is gonna make a bigger difference than the specific leaf springs.

After that is torque for me.  My Suburban 2500 with a 6.0 4L80 is rated to tow 11,000 lbs and while the chassis feels ok with up to that amount it really isn't happy with much over 6,500 for a long highway drive (every hill is a downshift and that gets REALLY tiresome).  By comparison my sisters F350 6.7 diesel is effortless with any load I've hooked to it yet.  

So to answer the question, for a shorter tow (around town) I'm comfortable towing about anything and taking my time.  But if I'm going down the highway for hundreds of miles, it's closer to 50% of "capacity".

I mirror what has been said in many ways above.

I have owned from small trucks to a 1 ton dually, and there is no question the truck is a large factor in my comfort with how close to the limit I'll tow.

I owned a 2019 RAM 1500 that was unhappy with basically any load behind it.  I sold it and eventually bought my 2005 RAM 2500 diesel quad cab with an 8' bed and it makes towing nearly anything very easy.

While some of that ease is courtesy of Cummins power, I think the overall heft of the truck combined with its length gives me comfort that it never feels like the tail is wagging the dog.

With that truck, I'm comfortable with towing around 90% of its tow rating which is about 14k lbs.  The final 10% is preserved to account for passengers in the cab (including my fat rear), our gear, and fluids etc.  All of those things add up quickly.

However, also as stated above, the attentiveness and skill of the driver can make a huge difference.

I work in a profession where I drive a company car and am on the road every day.  I need to protect my driving record and maintain the company car so I'm very aware of my surroundings all the time.   Im constantly glancing at all 3 mirrors while maintaining eyes forward watching for slowing traffic or emerging issues.  My brain is hyper focused on potential negative outcomes and as a result I'm looking for dangerous conditions almost subconsciously .

I think the third component involves the condition of the tow vehicle as well as the setup.  Obviously anything safety related needs to be in great shape, and things like air pressures make a huge difference.  On a related note, having a weight distributing hitch that is properly set up is a great way to feel comfortable when hurtling down the highway with 10k lbs out back.

A 1 ton truck with under inflated tires (and many of them are for the sake of ride quality) can be more dangerous than a properly set up half ton.  Like so many things in life towing offers a lot to consider before setting out on the road.

In reply to Loweguy5 :

Well said.