Is a 3.73 axle ratio good for towing?

A 3.73 axle ratio can be a good choice for towing, as it provides a balance between power and fuel efficiency. The axle ratio is an important factor in determining a vehicle's towing capacity and performance, and the optimal ratio can vary depending on the specific vehicle and towing needs.

Understanding Axle Ratios

The axle ratio refers to the number of times the driveshaft rotates for every single rotation of the vehicle's wheels. A higher axle ratio, such as 3.73, means the driveshaft rotates more times per wheel rotation, providing more torque and power for towing and hauling heavy loads. However, this also results in lower fuel efficiency at highway speeds.

Conversely, a lower axle ratio, such as 3.21 or 2.73, is better suited for highway driving and improved fuel economy, but may not provide enough power for towing heavy trailers or hauling large payloads.

Factors to Consider for Towing

When choosing an axle ratio for towing, there are several factors to consider:

• Towing Capacity: The axle ratio should be matched to the vehicle's towing capacity to ensure it can handle the weight of the trailer and cargo.


• Terrain and Driving Conditions: Steeper hills and mountainous terrain may require a higher axle ratio for more torque and power, while flat highways may benefit from a lower ratio for better fuel efficiency.


• Vehicle Type: Trucks, SUVs, and other larger vehicles typically have higher axle ratios to accommodate their towing and hauling needs, while smaller cars and crossovers may have lower ratios.


• Personal Preferences: Some drivers may prioritize power and towing performance, while others may value fuel economy more highly.

In the case of a 3.73 axle ratio, this is a common choice for many trucks and SUVs used for towing, as it provides a good balance of power and efficiency for a wide range of towing and hauling tasks.

Conclusion

A 3.73 axle ratio can be a good choice for towing, as it offers a balance of power and fuel efficiency. However, the optimal axle ratio will depend on the specific vehicle, towing needs, and driving conditions. It's important to carefully consider all the factors to ensure the right axle ratio is selected for your towing and hauling requirements.

What is a 3.73 gear ratio good for?

A 3.73 gear ratio is a good all-around choice for improving a vehicle's acceleration and towing performance without sacrificing too much highway drivability. It's considered a balance between gears focused on maximum fuel economy (lower numbers, like 3.55) and gears optimized purely for quick acceleration (higher numbers, like 4.10).
 
What a 3.73 gear ratio is good for

• Better acceleration: It provides more torque to the wheels, resulting in quicker off-the-line performance and a more responsive feel. 
• Improved towing: The extra torque makes it easier to tow heavier loads, as the engine doesn't have to work as hard. 
• Compensation for larger tires: It can help a vehicle with larger tires regain lost performance and acceleration. 
• Good for street/strip use: It offers a good compromise for performance applications like street trucks or drag strip use. 

What a 3.73 gear ratio sacrifices

• Fuel economy: The engine will have to spin at a higher RPM to maintain the same speed as a vehicle with lower gears, which can reduce fuel efficiency.
• Top-end speed: It can result in a lower top-end speed compared to higher gears because the engine will reach its redline at a lower vehicle speed. 

How it compares to other ratios

• vs. 3.55: A 3.73 ratio offers better acceleration and towing than a 3.55. A 3.55 is generally better for highway cruising and fuel economy. 
• vs. 4.10: A 4.10 ratio provides even quicker acceleration and more torque but at the cost of higher RPMs at highway speeds and reduced fuel economy. A 3.73 is often preferred for better highway comfort. 

What is the best axle ratio for towing?

The best axle ratio for towing is a higher, more numerically aggressive ratio like 3.73 or 4.10, as this provides more torque for pulling heavy loads. A ratio around 3.55 is a good balance for occasional or lighter towing, while a ratio around 3.23 or lower is best for fuel economy and not recommended for heavy loads. 
You can watch this video to learn how axle ratios affect towing: 59sGREYWOLF RVYouTube · Jul 20, 2025
For frequent or heavy towing:

• 3.73: A common and effective ratio for towing heavier loads. It offers a good balance of power and acceptable fuel economy for regular towing use. 
• 4.10 (or higher): Ideal for the heaviest loads, such as those exceeding 30,000 lbs. This ratio provides maximum mechanical advantage but will result in lower fuel economy on the highway, as the engine will run at higher RPMs. 

For occasional or light towing:

• 3.55: A popular choice that strikes a balance between towing capability and fuel efficiency, suitable for those who tow occasionally or with lighter loads. 
• 3.42: Often a good "all-around" ratio for a mix of daily driving and lighter towing, but may be underpowered for very heavy loads. 

Other considerations

• Transmission: Modern transmissions with more gears (8- or 10-speed) can help compensate for a lower axle ratio, allowing the truck to still perform well for towing. 
• Engine Type: Diesel engines typically have a high amount of torque, which may allow for a lower axle ratio without sacrificing towing performance. 
• Tire Size: Taller tires will increase the effective final drive ratio, making the vehicle's gearing "taller" and reducing torque output. A lower axle ratio may be needed to compensate. 
• Durability: Using a higher numerical gear ratio when towing heavy loads can improve the vehicle's durability and performance, as it provides a greater mechanical advantage. 

What is the 60/40 rule for trailer axles?

Before loading anything into the trailer, take a quick inventory of your cargo and roughly plan out where you'll be placing it in the trailer. The rule to follow is 60/40. 60% of the trailer load should be in front of the axle, and 40% should be behind. This will help ensure proper tongue weight to deter trailer sway.

What is the 80 20 rule for towing?

The "80/20 rule" for towing is a guideline suggesting you should not tow a trailer with a Gross Vehicle Weight Rating (GVWR) that exceeds 80% of your vehicle's maximum towing capacity. This provides a 20% buffer for safety, comfort, and to account for variables like extra gear, passengers, and road conditions. The primary benefits are improved safety, reduced wear and tear on the vehicle, and better control.
 
Why the 80/20 rule is recommended 
This video explains the 80/20 towing rule and why it's important: 54sThe Northwoods RV LifeYouTube · Jan 23, 2022

• Improves safety: It helps maintain better control, especially during emergencies, on steep inclines, or in windy conditions. 
• Reduces vehicle strain: Operating below the maximum limit reduces stress on your engine, brakes, and transmission, which can prolong their lifespan. 
• Accounts for real-world variables: The rule provides a buffer for factors not always accounted for in the manufacturer's ratings, such as cargo, passengers, and variations in road conditions. 
• Prevents overloading: It's a simple way to avoid exceeding your vehicle's limits, which can be illegal and dangerous, and could lead to breakdowns or frame damage. 

How to apply the rule

1. Find your vehicle's max towing capacity: Check your owner's manual or the sticker on the driver's side doorjamb for the maximum weight your vehicle is rated to tow. 
2. Calculate 80%: Multiply your vehicle's max towing capacity by 0.800.800.80 to find your recommended maximum trailer weight. 
   • Example: If your vehicle's max towing capacity is 10,00010 comma 00010,000 lbs, your 80% target is 10,000×0.80=8,00010 comma 000 cross 0.80 equals 8 comma 00010,000×0.80=8,000 lbs. 
3. Verify trailer weight: Ensure the trailer's GVWR is less than your calculated 80% limit.