Selecting the Best Tow Vehicle
Geared up to Tow your RV
Choosing a truck to pull a camper is an important decision for RVers since getting there and especially safely is the first and most essential aspect of living the RV Life! When towing a trailer, it is essential that the truck can handle the weight and size of the camper. Ideally, the specifications given by the manufacturer should serve as a guide for what the truck can tow safely. Nonetheless, people regularly overload their trucks or choose a trailer that is beyond the capabilities of their vehicle. In time, this often results in accidents or having to fork over a lot of money for repairs. This is why it's so important to be careful when choosing a tow vehicle.
​
Although the truck-trailer combo maybe just be a little out of spec on paper, it's not worth putting yourself in danger. Not only is it incredibly uncomfortable to drive a truck that's working overtime to tow a heavy load, but if you have an accident and investigators discover your truck was carrying beyond its safety limit, you will be held responsible.
Salesmen for trucks and trailers are useless. We've heard it all before: "That truck will be ideal for this trailer," or "This trailer will have no trouble with that truck." My advice, “Show me the data!” If you're concerned that your truck "might" be on the small side because your trailer puts it on the limit of its specifications, you'll need a bigger vehicle or a smaller trailer.
How to Size a Truck for safe towing
TRUCK and TRAILER WEIGHT RATINGS
The weight classifications for trucks and trailers are a jumble of letters, making it somewhat difficult to understand. Here’s a synopsis:
UVW = Unloaded Vehicle Weight. The weight of the vehicle without fuel, people and stuff.
GVW Rating = Gross Vehicle Weight Rating. The heaviest weight the vehicle can safely be when it is loaded up with fuel, people and stuff.
GCWR = Gross Combined Weight Rating. The most a truck-and-trailer combo can safely weigh when hitched together and loaded up with people, fuel, food, etc
Payload = The GVW rating less the UVW. The amount of weight the truck can safely carry.
PW = Pin Weight. The actual weight on the truck’s rear axle when a trailer is hitched up.
​
Start with your Use Case.
The best place to start when sizing your truck is to first understand your towing use cases. What do you plan on towing now and potentially down the road? If you're interested in RVing and plan on starting with a smaller, used 5th wheel, but would eventually like to move up to a massive Toy Hauler 5th wheel, you'll need to consider both scenarios. You don't want to be caught off guard later down the road and have to trade in your truck.
Two Key Steps:
-
Calculate your Max Payload and ensure it's below the truck's MAX allowable Payload.
-
Determine your GCW and ensure it's also below the truck's GCWR.
To determine the right size of tow vehicle, you'll need to start by calculating your total payload requirements. This is everything your tow vehicle will have in it as well as the Pin Weight. To tally up this figure I would start with the heaviest items first, that's your Pin Weight. 20% of a fifth wheel's GVW Rating is a good place to start in estimating the MAX loaded pin weight. So let's consider a few common 5th wheel sizes.
​
-
A small 5th wheel RV would be 25'~31' long and between 9,995 Lb GVW - 12,500 Lb GVW.
-
A medium sized 5th wheel RV would be 32'~42' long and between 15,000 Lb GVW and 16,800 Lb GVW.
-
A large size 5th wheel would be 43' - 45' long and between 16,800 Lb GVW to 20,000 Lb GVW.
If you're interested in a small RV having 12,500 Lb GCW Rating then 20% of that weight, 2,500 Lb, would be your Pin Weight. In addition to this, add your other payload items(people, diesel fuel, DEF, dogs, camp chairs, coolers, tools, etc.). The sum of all these items would be your maximum payload.
You can start to filter truck sizes by your payload requirements but once you've narrowed down your selection you also need to ensure you're staying below the truck's GCWR. This is the Gross Combined Weight Rating of your truck that takes into consideration the entire truck-and-trailer combo weight when hitched together and loaded up with people, fuel, food, motorcycles, bikes, grills, etc. As long as your payload and GCWR are both lower than the truck's maximum rating, it should be a good choice for towing.
Two Common Towing Scenarios
Towing a 5th Wheel Toy Hauler
If you interesting in towing a top of the line 5th wheel toy hauler, its max weight is generally 20,000 Lb. In this case, you're looking at a max pin weight of 4,000 Lb. Now consider the other elements to your payload. 4 people each at 195 Lb, one dog at 45 Lb, a generator at 100 Lb, Yeti cooler at 50 Lb, standard 5th wheel hitch at 110 Lb, misc. items at 50 Lb, a full DEF Tank at 45 Lb (5 gallon tank at 9 Lb per gallon) and a full 50 Gal Fuel tank at 350 Lb (7 Lb per gallon of diesel) ; all of these items total 1,530 Lb. Combining this with the trailer Pin Weight gives you the total payload requirement of 5,530 Lb. This figure instantly lands you in Dually Truck territory because the max payload for any Single Rear Wheel truck on the market today is from 2,890 to at most 4,580 Lb, well below what's needed here.
Towing a Luxury 5th Wheel, My Condo on Wheels
This is my current situation. I wanted to buy a 43' 5th wheel that had a maximum trailer weight of 16,800 Lb. Taking the trailers GVW rating times 20% will estimate your maximum pin weight on the truck at 3,360 Lb. Next we have to tally up the other items that contributes to the overall payload of the truck. This includes, 2 Adults each at 150 and 200 Lb, 2 kids w/carseats at 150Lb, one dog at 45 Lb, a generator at 100 Lb, a full propane tank at 45 Lb, Yeti cooler at 50 Lb, standard 5th wheel hitch at 110 Lb, dog food at 40 Lb, tools at 200 Lb, Stand-up Paddle Board at 50 Lb, compact air compressor at 50 Lb, misc. items at 125 Lb, a full DEF Tank at 45 Lb (5 gallon tank at 9 Lb per gallon) and a full 50 Gal Fuel tank at 350 Lb (7 Lb per gallon of diesel). This totals 1,860 Lb and so combining that with the trailers pin weight of 3,360 Lb has the grand total at 5,220 Lb for my payload.
My GCWR would be Truck Base Weight (8,429 Lb)+ Misc Payload (1,860 Lb) + Trailer GVW (16,800) for a grand total of 27,089 Lb. In this case, every well-equipped 1-ton truck with a single rear wheel would be sufficient from a GCWR standpoint. However, it's the payload that is the limited factor. With that mind, only Dually 1-tons would be enough truck to handle my payload requirements.
Important Note: Fifth wheel trailers typically have a pin weight of 15-20% of their gross trailer weight (GTW) rating. The most accurate way to gauge your 5th wheel trailer's loaded pin weight is by utilizing a commercial semi-trailer scale. To do this, you first attach the trailer to your truck and drive onto the scale so that only the 4 wheels of your truck are positioned on it. Make note of this weight, then detach the trailer and weigh just the truck; The difference between these two numbers will be your trailer's loaded pin weight. Although OEMs generally show towing capacities with a 15% pin weight that is considered the ideal level, your value will differ depending on how the trailer is loaded and your hitch height in relation to the trailer. I suggest using 20% for safety reasons.
PICKUP TRUCK SIZES
Decades ago, the truck naming convention arose from the original payloads these trucks could carry. For example, a half-ton truck could transport 1,000 lbs (half a ton) in its bed. Similarly, a three-quarter-ton truck could hold 1,500 lbs and a one-ton truck 2,000 lbs.
The original truck model names indicated the maximum payload weight that the truck could carry. However, as technology progressed, newer trucks are now able to hold much more than their predecessors. For example the payload of a 2022 Ram 3500 diesel can be up to 6,170 lbs., making it more comparable to a "three-ton" truck than a one-ton.
In today's trucks, the main distinction between a three-quarter ton 250/2500 and a one-ton 350/3500 is the beefiness of the rear end suspension, which must support a heavy load and hence has more leaf springs on the rear axle. To me, if you're going to spend the money on a three-quarter-ton truck for towing, you might as well go all out and get a one-ton.
I've put together a list of the most popular vehicles that fifth wheel owners are thinking about as they look hunt down the best tow vehicle for their needs. Please keep in mind that these values are from 2021/2022 model years and this is only meant to be used as a reference guide. When you're looking for your vehicle, make sure to double check the specs so that it meets your specific needs.
LONG BED vs. SHORT BED PICKUPS: WHICH IS BETTER?
Pickups have two bed sizes to pick from. A “short bed” truck has a box that is approximately 6' long, and a “long bed” truck's box is 8', give or take. Keep in mind that a fifth-wheel hitch is installed over the rear axle in the bed of a pickup so that the kingpin will be directly above it. This leaves less distance between the hitch and back of the cab if you have a short bed truck as opposed to a long bed truck.
The main advantage of having a compact bed truck is that the two axles are closer together. This means that the truck can turn tighter, which comes in handy when parking or executing u-turns. When parked, it takes up less space overall; this works well in congested areas where there is little room to maneuver.
When towing a fifth-wheel trailer, the front of the fifth-wheel cap might hit the rear of the pickup cab during tight turns. To prevent this, there are special fifth wheel hitches that slide.
The main advantage of a long bed truck is that it can not only carry more stuff in the bed, but also turn tightly without damaging the fifth wheel trailer against the back of the truck cab.
Additionally, you can open and close the tailgate even when the fifth wheel trailer is hitched up. We can walk from one side of our trailer to the other through the space between an open tailgate and front of trailer - even while truck is making a tight turn.
If you don't plan to tow often and only go camping a few weekends per year, then a short-bed truck will likely suffice. However, if you do tow frequently or are an RV enthusiast who travels long distances, we recommend opting for a long-bed truck.
Even though we have to park away from the crowd and walk a bit further, and even though we occasionally struggle with u-turns and tight maneuvering (a long bed pickup without the trailer attached still takes almost four lanes to do a U-turn), we have never once regretted having a long bed truck.
SINGLE REAR WHEEL vs. DUALLY - What's the better choice?
In the one-ton category, there's another factor to bear in mind: single rear wheels on the truck (SRW = “single rear wheel”) or two pairs (DRW = “dual rear wheel" aka, "Dually" )
A single rear-wheel truck has the following advantages:
-
Fewer tires to maintain - Only 4 tires instead of 6
-
No inner tire to change out
-
There's no need to worry about a big rear fender while paying tolls or going to a drive-through restaurants.
-
The truck grips the road better than a dually in icy, snowy and muddy conditions. Can handle rough two-track roads better because the rear wheels fit neatly into the ruts
-
You can still go through most Automated Car Washes. Dually Trucks cannot.
Advantages of the dually:
-
A wider stance provides better support for the weight of a kingpin or bumper hitch.
-
Can tow a heavier trailer or camper due to increased payload capacity.
-
Redundancy. If a blowout happens on one of the back wheels, you're much safer and can still drive for some time.
-
Increased stability in a crosswind situation or when a Semi-Truck is going the other way on a two-lane highway.
-
The space between the 2 tires helps to drain water, snow and mud away, reducing the risk of hydroplaning.
-
The increased width of the wheel tracking lowers the center of gravity for the overall load, making it more stable.
-
With a One-ton pickup, your payload goes up by an additional 1,000 lbs. or more, making it the perfect choice for towing a heavy 5th wheel trailer. Weight adds up fast when you're planning to full-time in your RV! You will welcome the extra headroom!
DIESEL TRUCKS ON THE MARKET
It's no secret that people are fiercely loyal to their preferred brands, especially when it comes to big diesel pickup trucks. With Chevy/GMC, Ford and Ram all being reputable makes, it can be tough to decide which one is right for you. I'm not trying to start a truck brand war here! Ultimately, I chose RAM for a few key reasons I'll explain below.
​
My 3 Key Deciding Factors
​
FIRST, The Cummins Engine
In the end, the most important factor for me was a Cummins engine. Many people want a pickup truck that has both the Cummins engine and Allison transmission, which is common in commercial trucks. Unfortunately, no such model exists for pickups.
The simplicity of the inline 6-cylinder Cummins engine (as opposed to the more complex V8 engines in the Chevy and Ford) as well as its longer stroke (inherently higher torque) makes perfect sense. Inline engines are employed commercially in large trucks and tractors, and the 6.7 liter Cummins engine has a long track record of success, not just in Ram vehicles but also in many commercial applications. The quality control and production at Cummins appear to be world-class.
The Inline 6-cylinder Cummins 6.7 liter engine has been in production since 2007 back then it was producing 350HP and 650 ft-lbs of torque. Through continued refinement, the 2022 High Output Engine is at 400 HP and 1,075 ft-lbs.
SECOND, The Proven Transmission.
The Aisin AS69RC transmission, which is considered commercial grade is more durable and dependable and has been used for over a decade in the 3500s.
The AS69RC replaced the AS68RC in the 2013 model year and has been used ever since. It was made available on the Ram 3500HD, as well as the Ram 4500 and 5500 chassis cabs. The AS69RC included a new input shaft size, a modified torque converter design, and a deleted F1 sprag clutch for first and reverse gears, among other improvements. The Tow/Haul Mode of the AS69RC is also distinctive. To activate overdrive gears while preserving optimum performance from the Cummins Smart Diesel Exhaust Brake, simply press a button on the center stack.
​​
THIRD, The Proven Chassis and overall assembly.
After a near-decade run of the fourth generation trucks, Ram unveiled its new fifth generation HD truck line in 2019. To reduce weight and engine robustness, they use a compacted graphite block--75% stronger and 60 pounds lighter than before. Additionally, the chassis was modified to enhance its capabilities. The new rear axle allows for increased tow capacity and has larger bearings, housing, shafts, and brake rotors than the previous generation.Additionally, the engine modifications and exhaust updates work together to improve NVH (Noise, vibration and harmonics), which results in a quieter ride.
​
Other Specs to Consider when buying your Truck.
​
REAR AXLE GEAR RATIO
The number given as the "rear axle gear ratio" (4.10 or 3.73, for example) refers to the proportion of teeth on the ring gear attached to the rear axle compared with those on the pinion gear connected to the driveshaft. So, if a 4.10 rear axle ratio has a driveshaft that must rotate 4.1 times in order for its back wheels to turn one revolution, then it follows that at any given speed, that same drive will shaft will be turning faster than one with a 3.73 ratio-- whose driveshaft only has to rotate 3.73 times total for complete wheel revolution. So what's the point...... Keep reading!
Towing Heavy Loads vs. Driving Fast on the Highway
On a truck, the higher turn ratio (4.10) is best for towing heavy loads because it takes more turns of the driveshaft to rotate the rear wheels. In turn, the engine enters a higher RPM and more optimal power range for increased torque. However, top speed and fuel efficiency are slightly diminished.
If you frequently tow the heaviest trailers, it's best to get a truck with a 4.10 rear axle gear ratio. If you only tow occasionally and with lighter trailers mostly on highways, then you'll probably want a 3.73 rear axle gear ratio.
FOUR WHEEL DRIVE (4×4)
If you live the RV lifestyle like I do, then four-wheel drive is an absolute necessity. When traveling down steep, dangerous roads with grades, it's best to put your truck in low gear and creep down the mountain while using the exhaust brake. You'll also find yourself pulling into some RV parks with relatively steep gravel driveways that require four-wheel drive.
EXHAUST BRAKE
The 2022 Ram trucks come with an exhaust brake that has two modes: Full Exhaust and Automatic Exhaust braking. When you take your foot off the accelerator, the full exhaust mode will slow you down to a stop. When you're in Automatic mode, it will maintain your speed, which is ideal for downhill descents. In effect, you have redundant brakes ,which is a huge safety factor when towing .
By supplying negative torque to slow down the vehicle, this will help extend the life of your mechanical brakes and reduce brake fade.
AUTO-LEVEL SUSPENSION
You can now choose to have four leaf springs with computer-controlled air bags on the 2022 Ram trucks. This option will provide for auto-leveling of the rear suspension, as opposed to the standard sixleaf springs without airbags that come with a fixed height suspension.
The truck's on-board compressor activates when the trailer is hitched, filling the air bags and steadily elevating the back end until it reaches its regular one inch rake.
Test driving both trucks with and without a load, we found the dual auto-leveled suspension model rode much smoother than the leaf spring only one.
​
​
My 2022 RAM 3500 TRUCK Options & Comments:
-
Ram Laramie Crew Cab 4×4 3500 Long Bed
-
Engine: 6.7L I6 Cummins HO Turbo Diesel Engine
-
Alternator: 220-Amp (Sufficient option, but having the dual Alternator is ideal for 5th wheel power when you're driving down the road)
-
Exterior Color: Delmonico Red Pearl-Coat
-
Transmission: 6-Speed AISIN AS69RC HD Automatic Transmission
-
4.10 Rear Axle Ratio
-
5th Wheel / Gooseneck Towing Prep
-
50-Gallon Fuel Tank (Must have - it should be a standard option)
-
Dual Rear Wheels
-
Auto-level rear suspension (This provides the smoothest ride for any heavy duty on the market. Get it! You'll thank me later.)
-
Adaptive Cruise Control w/ Stop (Unfortunately, this option was very disappointing and not worth the money.)
-
HD Snow-Plow Prep Group
-
Chrome Appearance Group w/ Chrome side steps
-
Backup Camera
-
Instrument panel auxiliary switches
-
ParkSense Front and Rear Park-Assist System (If you don't have surround view cameras, this parking assist feature is a must-have.)
-
Spray in bedliner by Mopar
-
LT235/80R17E BSW All-Season Tires (I would have preferred the On/Off Road Option)
-
Interior Color: Black Leather-Trimmed Bucket Seats
-
Heated/Vented Leather Seats and Heated Steering Wheel
-
20K Direct Mount 5th-Wheel Hitch by Curt
-
Power adjustable pedals
-
UConnect 5 Nav w/ 8.4-inch Touch Screen Display w/ CarPlay (Works great!)
-
9 Alpine Speaker w/ Subwoofer
ENJOY THE JOURNEY!