A tow vehicle needs to have enough power to tow a trailer. If that is not the case, some states will fine you heftily, and you have to park your trailer until you get a tow vehicle with enough power. If you have a heavy trailer, more than 7,000 pounds, finding an appropriate tow vehicle becomes challenging. Most of the tow vehicles are rated lower than 7,000 pounds.
Table of Contents
- What Size Engine Do You Need For Towing?
- Minimum Engine Size For Towing – Petrol vs Diesel vs LPG?
- What Size Engine To Tow A Horse Trailer? HP Vs Torque For Towing
- What Size Engine Do You Need To Pull A Boat?
- What Size Engine Do You Need To Tow A Trailer?
- Besides the Engine, What Else Affects the Towing Capacity of a Vehicle?
- Engine Size For Towing
What Size Engine Do You Need For Towing?
You need one horsepower to tow about 25 pounds. You will need at least 100 horsepower to tow a 2,500-pound trailer, but not all 100-hp engines can pull such a trailer. There are several other factors that affect how much a truck can pull besides the horsepower.
While comparing horsepower to towing capacity is usually a good way to ballpark your maximum towing capacity, you need more information before you can safely tow with your vehicle.
You can tell a vehicle’s towing capacity by looking at its user manual. The manual will show you the year, the model, and other details on how to tow a trailer or a boat behind your vehicle.
If you are comparing different vehicles, it is easier to check the towing information online. To be sure, check the manufacturer’s website, and you will have the right details.
Manufacturers always list the vehicle’s max towing capacity. To achieve the max capacity, you need to fit your trailer with brakes and have a specialized towing setup.
With normal towing, the vehicle might not reach the recommended maximum towing capacity.
After you establish your towing needs, you need to pick a vehicle whose towing capacity is above your needs. This way, you will not have issues with overloading your vehicle.
Minimum Engine Size For Towing – Petrol vs Diesel vs LPG?
Diesel engines are the best when you need to tow heavy loads and you tow often. Diesel engines produce high torque, making them ideal to tow heavy loads.
The flat torque curves that the diesel engine produces make them more suited for the tasks.
With a high torque, the truck has the capability to start moving from a stop. However, you may not get the true picture of the power of a vehicle by looking at the specifications in the manual.
It is not uncommon to find vehicles with 2.0 or 2.5L diesel engines generating as much torque and power as larger petrol engines.
However, if you get a small diesel engine that relies on its turbocharger to generate power, it may not offer as much torque as a larger engine that doesn’t rely on a turbocharger.
While there are smaller diesel engines that tow more than some larger engines, we recommend you go for a larger unstressed engine for your camper.
If you know someone with a smaller diesel vehicle that they use for towing, you can ask them about the performance of the vehicle before you buy one.
Diesel engines are more fuel-efficient than petrol engines. However, fuel efficiency alone may not be a justification to pay thousands of dollars more than you would for an equivalent petrol engine.
Unless you are always on the road, fuel efficiency should not be a big concern when choosing the best engine for towing.
If you decide to go for a diesel engine, you need to know that these engines are expensive to maintain. Parts, such as filters and other components, will be expensive for diesel engines.
Petrol engines may not offer as much torque as diesel engines, but they are more affordable to buy and maintain.
However, fuel consumption might be higher when you tow your camper with a petrol engine. Note that fuel efficiency is also dependent on the make and model of the vehicle you use to tow.
LPG-powered vehicles are an affordable alternative to expensive diesel engines. LPG doesn’t work for every vehicle, but it reduces fuel costs significantly when you are towing.
How Heavy Are Campers?
Campers and their hitches are available in different configurations and size classes.
Class A campers are the largest you will see on the road. These beasts weigh between 13,000 and 30,000 pounds. These campers have several amenities, including king-size beds, mobile garages, washers and dryers, and many more.
Class B campers are between 4,000 and 9,000 pounds. They are also known as camper vans. They are smaller than Class A campers.
Class C campers are bigger than class B campers but smaller than class A, making them a good mid-size option. Most of them weigh between 10,000 and 13,000 pounds.
These RVs come with a separate bathroom area and several other amenities. To tow these and the class A campers, you need the engine in a heavy-duty truck.
What About Pop-Up Campers?
Popup campers are light; most of them weigh between 500 and 3,200 pounds. You can tow these with a compact or midsize truck.
What Size Engine To Tow A Horse Trailer? HP Vs Torque For Towing
Horse trailers carry one or more horses. The weight of the trailer will be between 1,300 and 10,000 pounds when empty, depending on the number of horses they accommodate.
A one-horse trailer weighs between 1,300 and 2,700 pounds without a horse inside. The horse adds about 800 pounds, and you may have other items such as food and water inside the trailer.
Two-horse trailers weigh between 2,000 and 10,500 pounds.
The huge weight difference is a result of the construction materials and style, with fiberglass and aluminum trailers being lighter than steel trailers.
A three-horse trailer will weigh between 3,000 and 7,500 pounds, while a four-horse trailer can be between 3,000 and 15,000 pounds.
Most of the heaviest multiple-horse trailers do not go beyond 15,000 pounds. These large trailers need a heavy-duty or super-duty truck to pull.
Some midsize trucks can pull small one-horse trailers, while full-size trucks can pull some two-horse and three-horse trailers. Ensure you consider the horse’s weight and any load you will carry in the trailer.
How much torque for towing a horse trailer? Is torque more important than power when towing a horse trailer?
Torque is more important than power when you are towing. It gives you the ability to accelerate your vehicle at low RPM.
It is torque that starts your vehicle from a stop and the same that helps you take on a steep hill.
Granted, you need more torque to start a tow vehicle than you need to start a lighter vehicle. With more torque, your vehicle is able to pull even the heaviest horse trailers.
If you have ever been keen on TV ads on vehicles, manufacturers advertise horsepower for performance cars and torque for commercial trucks.
The towing capacity of the vehicle refers to the amount of weight that that vehicle pulls behind it. Trucks that have a high towing capacity have a high torque. This high torque turns the crankshaft, which connects to the transmission of the vehicle.
When the tow turns the crankshaft, the transmission gears convert the torque into energy to enable the vehicle to move and tow cargo safely.
Any driver who tows often knows that your vehicle is more powerful when on lower gears. You will also realize that when you are in high gear, you will not accelerate enough to overtake other drivers even if you have more horsepower than the other drivers.
When moving up a hill, you will need to move slowly. At these high RPM levels, having a lot of horsepower will not help.
Here, you need low-end power, which only comes when you have a sufficient amount of torque.
Horsepower is important when you are driving at high speeds or at high RPM levels.
It is what helps you overtake other vehicles on the road. However, there are speed limits for when you tow, and you may never need to drive your tow vehicle at very high speeds.
The more you accelerate, the more the RPM levels rise, and the more you need high-end power.
If your engine doesn’t have enough horsepower, you may have the power to accelerate from a stop and drive up a hill, but the vehicle will not be fast enough to overtake other drivers on the road.
Because towing puts a lot of stress on your vehicle, you need a high-torque engine to reduce wear and tear. If you can go for a diesel engine, pick one as it offers more torque than a petrol engine of the same size.
What Size Engine Do You Need To Pull A Boat?
There are small boats that even a car (if well-equipped) can tow. However, there are also large boats that need the largest engines to tow.
Ski boats weigh an average of 3,500 pounds. These are easy to tow even with most midsize trucks and some compact SUVs. However, you have to consider the weight of the boat trailer.
Speed boats can weigh up to 8,000 lbs. For these, you need a full-size or a heavy-duty truck to tow. You also need accessories such as trailer brakes to ensure that you are safe on the road.
Small fishing boats are easier to tow. These have an average weight of about 1,700 pounds, and you can tow them with compact trucks and crossovers.
Sailboats and cabin cruisers are larger and weigh an average of 8,800 pounds. This is a heavy load that even some full-size trucks may not handle.
You need powerful full-size or heavy-duty trucks to tow such a boat.
Pontoon boats and deck boats weigh about 3,100 pounds. Most SUVs, some crossovers, and some midsize trucks can tow such boats.
PWCs are light boats that weigh less than 1,000 pounds, and you can tow them even with your car or your van.
What Size Engine Do You Need To Tow A Trailer?
What size engine is needed to pull a travel trailer? These trailers are available in different sizes, materials, and styles, and these factors influence the trailer’s weight.
Trailers can weigh anything between 200 and 16,000 pounds. The smallest kayak trailers only need a car to pull, but the largest fifth-wheel trailers need a heavy-duty or super-duty truck to pull.
Trailers come in different materials, including aluminum, steel, and fiberglass. The last two are relatively lighter, while steel is heavier but stronger and more durable.
The trailers are also available in different styles, from enclosed trailers to flatbed trailers, which can dramatically increase their maximum weight. The sizes will also determine how much engine power you need to tow them.
Check the size and weight of your trailer and compare that with your vehicle’s towing capacity. Always consider the weight of the hauling accessories, the weight of the cargo you carry in the trailers, and the payload capacity of your vehicle.
Besides the Engine, What Else Affects the Towing Capacity of a Vehicle?
The Transmission System
Automakers no longer fancy making vehicles with manual transmissions. Even when they use manual transmissions, they are used on smaller vehicles and not work trucks that need a lot of power.
There are lower internal power losses in manual gearboxes that only small cars can accommodate.
Automatic transmission offers the flexibility you need to handle large engines. You will find it easier to drive a vehicle with a large engine as long as the engine mates to an automatic transmission.
With an automatic transmission, your clutch will last for many years as you never have to use it during every hill start and when you need to maneuver in a busy street.
If you compare vehicles with an automatic transmission to those with manual transmission, you will see that those with an automatic transmission have a higher towing capacity.
If your tow vehicle has an automatic transmission system, and you tow often, the car vehicle should have a large cooler to ensure the system doesn’t overheat.
Which system should you go for? There is no direct answer to this, but the automatic transmission system has a host of conveniences that most drivers like.
FWD, RWD, or AWD for Towing?
For a long time, six- or eight-cylinder engines with rear-wheel drive have become popular for towing. However, today, manufacturers are fitting tow vehicles with a front wheel drivetrain.
You will come across so many six-cylinder engines with front wheel drivetrain that have ample towing capacities.
Whether your vehicle is a front wheel or rear wheel, it can tow perfectly as long as you do not exceed the manufacturer’s towing recommendations.
If your vehicle is front-wheel drive, it will be less drivable if load distribution is poorly done. Other drivetrains will suffer from poor distribution of load, but FWDs are more sensitive.
Again, four-wheel drive will have less traction if you drive them on slippery roads.
AWDs are better when you need more traction. However, these drivetrains have more technical sophistication, weight, and complexity of driveline. They will consume more fuel and their maintenance costs will be higher.
If you want more traction and more stability when towing, AWDs can be great choices for you.
What about 4WDs?
Four-wheel drives are popular in several tow vehicles. These 4X4 vehicles are ideal when you need to tow off-road or on ice and other tough terrains.
You may find passenger cars fitted with 4WD systems to make them better at pulling heavy loads off the road.
Trucks with 4WD systems are able to pull heavy loads without the speed restrictions that you see in passenger vehicles.
While a 4WD system is not essential when you need to tow heavy loads, it will come in handy for applications that need traction and when you drive off the road.
Does Displacement Matter?
Displacement refers to the cylinder volumes in a vehicle engine. Vehicles with more volume are able to hold more air in their cylinders and, consequently, burn more fuel and deliver more torque.
There is a direct correlation between the torque a vehicle produces and the displacement in its cylinders.
Vehicles with more displacement are able to drive more smoothly and will suffer less wear and tear.
For instance, if a 1.6L car and a 2.0L car all drive at 100 kilometers per hour, the 1.6L car will reach that speed with about 3,000 revolutions per minute.
The other car will reach the same speed at about 1,500 revolutions per minute.
Because the car with a lower displacement works harder to reach the top speed, there will be more wear and tear on its parts compared to the other car.
Tow Vehicle Weight
Your tow vehicle weight is very important. Further, the Gross Weight (GVWR) is also important, and it refers to the total weight allowed for your vehicle.
GVWR accounts for the curb weight, the trailer, the load, and the passengers in the vehicle.
You should never exceed the GVWR of a vehicle. There are many factors that affect the weight of your tow vehicle.
For instance, a 4×4 truck or SUV will be heavier than other vehicles, and this diminishes the amount of cargo you can carry and the trailer the engine can pull.
If you do not drive off the road, or you only do light off-roading, you can stick with a rear-wheel-drive to minimize the weight of the vehicle.
To calculate how much your vehicle can tow, you need to check its GVWR from the user manual. Next, check your vehicle’s curb weight.
The curb weight is the weight of a vehicle without any load but with the necessary fluids.
Subtract the curb weight from the GVWR and see what you have left. For instance, a 2020 Ford F-150 weighs about 4769 pounds and a gross weight of about 6,500 pounds. This truck, therefore, can only carry 1731 pounds in it.
When you tow, the tongue weight will be between nine and 15 percent of the trailer weight and the cargo in the trailer.
For instance, if the weight of a loaded trailer is 10,000 pounds, the tongue weight will be between 900 and 1,500 pounds.
With the Ford F-150 above, you can carry up to 1,731 pounds. The passengers in the cabin and any payloads will reduce the amount you can tow.
If the passengers weigh about 600 pounds and there are suitcases that weigh about 131 pounds, you will only have 1,000 pounds left to tow.
As a rule of thumb, avoid towing any weight that is close to the rated towing capacity.
The maximum towing capacities of vehicles consider the best appropriate towing conditions such as having trailer brakes. The recommended capacity also assumes the vehicle is in good condition.
Engine Size For Towing
Towing with any vehicle or any engine requires skills and caution. For starters, ensure you have the right accessories such as trailer brakes, the right hitch, and any other accessories you may need.
You also need trailer lights for safety when you tow at night.
In some states, you cannot tow unless you have the safety accessories such as lights and brakes.
However, these may not be requirements in some states. We recommend that you have these safety accessories on your tow vehicle so that you can tow safely.
Even if you have the most powerful engine, you still need to maintain your vehicle to ensure it is in good condition.
Although the size of the engine matters, there are so many other factors that determine how well a vehicle tows.
For instance, some small cars can tow trailers that are less than 1,000 pounds heavy.
However, the structure and frame of these cars were not engineered to tow.
Towing often with such a car will affect its durability and make maintenance more expensive. Further, the automaker may cancel your warranty if you tow with such a car.
Trucks and most SUVs, on the other hand, can tow every day without damaging their bodies.
Take your time and pick the best tow vehicle.