What is a 3.73 gear ratio good for?

A 3.73:1 rear-axle gear is a balanced, mid-range gearing that boosts initial acceleration and towing capability without excessively compromising highway efficiency. It’s a versatile choice for everyday driving with moderate loads.

In automotive terms, the gear ratio describes how many engine rotations are needed to turn the wheels once. A 3.73 ratio multiplies engine torque at the wheels more than lower-numbered gears and reduces top speed slightly compared with taller gears. The suitability of 3.73 depends on engine size, transmission, tire size, and how you use the vehicle—whether you’re hauling, off-roading, or cruising on highways.

Understanding where 3.73 fits

To understand how this gearing translates to real-world driving, consider how the engine’s power is delivered to the wheels. A 3.73:1 ratio provides more torque multiplication at the wheels than lower gears, which improves launch and mid-range pulling ability, but it also keeps the engine rpm higher at a given road speed than taller gear ratios.

Performance implications

The following list highlights how a 3.73 ratio typically affects daily driving and performance.

• Quicker off-the-line acceleration and stronger mid-range torque, helpful in everyday merging and pulling away from stops.


• Enhanced towing and hill-climbing capability for moderate loads, especially in trucks and SUVs with V6 or smaller V8 engines.


• Higher engine RPM at highway speeds compared with taller gears, which can increase engine noise and fuel use on long highway trips.


• Better feel with moderate tire sizes (roughly 29–33 inches in diameter); larger tires raise the effective gearing and can offset some benefits.

In practice, these traits make 3.73 a solid choice for drivers who tow occasionally, drive in hilly or mountainous terrain, or want stronger acceleration without committing to a very aggressive gear like 4.10.

Who benefits from a 3.73 gear ratio

These scenarios describe typical users who gain the most from a 3.73 rear gear. The list highlights common vehicle types and use cases.

• Owners of mid-size trucks and SUVs with V6 or smaller V8 engines who tow or haul moderately heavy loads, such as trailers or boats.


• Off-road enthusiasts who need solid low-end torque for rock crawling, mud, and steep grades, while keeping highway performance reasonable.


• Drivers planning to upgrade tires from stock sizes (for example, moving to 31–33 inch tires) where a 3.73 helps maintain usable RPM without jumping to a much taller ratio.

For commuters who rarely tow or haul, or for those chasing maximum highway fuel economy, a taller ratio (like 3.31 or 3.55) or an even higher one (like 4.10) might be more appropriate depending on engine and tire size.

Trade-offs and considerations

Before selecting or changing to a 3.73 ratio, consider how it interacts with your engine, transmission, and tires, as these factors influence overall performance and efficiency.

• Fuel economy and highway RPM: a 3.73 gear typically raises RPM at highway speeds, which can reduce fuel economy and increase cabin noise on long trips.


• Tire size and final-drive effect: larger tires effectively raise the gearing, increasing engine RPM further; smaller tires dampen the effect.


• Vehicle weight and engine power: the benefits are more noticeable on heavier vehicles or those with smaller engines that struggle with load or steep grades.


• Speedometer and gearing calibration: changing gear ratios often requires recalibration of speedometers and odometers for accurate readings.

Ultimately, the decision to use or install a 3.73 ratio should weigh the need for better torque and towing against the desire for lower engine speeds and improved highway efficiency.

Summary

A 3.73 gear ratio is a versatile mid-range choice that enhances off-the-line acceleration, mid-range pulling power, and moderate towing capability, while sacrificing some highway fuel economy and top speed relative to taller gears. It suits drivers with daily use who also tow or venture into hills and rough terrain, especially when paired with appropriate tires and a compatible engine/transmission setup. For strictly highway-focused driving or frequent maximum-speed cruising, other gear choices may offer better efficiency.

Is a 3.73 ratio good for towing?

Yes, 3.73 gears are good for towing because their higher numerical ratio provides more torque, which improves performance when pulling heavy loads. While they offer better towing power and low-end acceleration, they result in higher engine RPMs, lower top speed, and poorer fuel economy compared to lower gear ratios like 3.55. 
This video explains the benefits of 3.73 gears for towing: 1mGetty's GarageYouTube · Jun 1, 2024
Advantages for towing

• More torque: The higher gear ratio gives the vehicle a mechanical advantage, translating more engine torque to the wheels for pulling heavy loads. 
• Better performance: They provide better performance for towing, especially for heavy loads and stop-and-go traffic, and are an upgrade for trucks with lower gears like 3.15 or 3.55. 
• Improved acceleration: They can improve off-the-line performance and acceleration, which is helpful when getting a heavy trailer moving. 

Disadvantages for towing

• Higher RPMs: The engine will operate at a higher RPM while cruising, which can lead to a less comfortable ride and worse fuel economy. 
• Lower top speed: The overall top speed is reduced. 
• Fuel consumption: Fuel economy is generally lower, especially on the highway, compared to a truck with a lower gear ratio. 

You can watch this video to see the effect of gearing on RPMs while towing: 58sGreat Lakes PowerstrokeFX4YouTube · Mar 14, 2025
When 3.73 gears may not be ideal 

• If you have a vehicle with a high-revving engine, like some V10s, 3.73 gears may keep the engine out of its optimal powerband, leading to a miserable towing experience, as detailed on Quora. 
• If your primary use is highway cruising and you rarely tow, lower gears like 3.55 are better for fuel economy and a quieter ride. 

What is the best gear ratio for burnout?

For burnouts, a higher number rear-end ratio like 3.73 or 4.11 is generally best because it increases torque to the wheels, making them spin faster and easier. A more aggressive ratio such as 4.56 or 4.88 is even better for burnouts and drag racing but can negatively impact highway cruising and fuel economy. For a compromise between daily driving and burnouts, 3.42 or 3.55 are good options. The ideal ratio also depends on your vehicle's engine, transmission, and tire size. 
Best ratios for burnouts
You can watch this video to learn about gear ratios for burnouts: 1mGearFX DrivelineYouTube · Feb 10, 2023

• 3.73: A popular and balanced choice that offers good acceleration for burnouts while still being manageable for daily driving. 
• 4.11: A step up in performance, providing even quicker acceleration and better tire spin for burnouts compared to 3.73s, but with a greater impact on highway RPMs and fuel economy. 
• 4.56 or higher: These are considered aggressive ratios that excel at burnouts and drag racing by providing maximum torque to the wheels. However, they are best suited for vehicles that do not see frequent highway use. 

Compromise ratios for daily driving and burnouts 

• 3.42: A significant upgrade from stock ratios, providing a noticeable improvement in acceleration for burnouts without sacrificing too much highway drivability. 
• 3.55: A good middle-ground ratio that offers better performance than stock but is still comfortable for highway cruising. 

How to choose the right ratio

• Prioritize: Decide whether your main priority is highway cruising or performance/burnouts.
  • If you drive a lot on the highway, a lower number ratio like 3.42 is more suitable. 
  • If your focus is on performance and burnouts, a higher number ratio like 4.11 or 4.56 is better. 
• Consider other components: Your vehicle's engine, transmission, and tire size will affect how a particular gear ratio performs. 
  • A transmission with an overdrive gear can handle lower, more aggressive ratios better for highway use. 
  • Engine specifications, such as camshaft profile, also play a role. 
• Use a calculator: Many online calculators can help you estimate the effect of different gear ratios on your RPMs at various speeds. 

Which is better, 3.73 or 4.10 gears?

Neither 3.73 nor 4.10 gears are inherently "better"; the choice depends on your driving priorities. 4.10 gears provide quicker acceleration and more torque, which is ideal for performance or heavy towing, but at the cost of lower fuel economy and higher engine RPMs at highway speeds. 3.73 gears offer better fuel economy and a higher top speed because the engine runs at a lower RPM on the highway, making them better for general cruising and long-distance driving. 
You can watch this video to see the difference in acceleration between 3.73 and 4.10 gears: 56sTheKingCoopaYouTube · Dec 17, 2021
4.10 gears

• Pros:
  • Quicker acceleration and a faster feel off the line. 
  • More torque, making them better for towing heavy loads. 
• Cons:
  • Lower fuel economy. 
  • Higher engine RPMs at highway speeds, which can lead to more engine noise. 

3.73 gears 

• Pros:
  • Better fuel economy. 
  • Higher top speed because the engine runs at lower RPMs on the highway. 
  • Quieter and more comfortable for highway cruising. 
• Cons:
  • Slower acceleration compared to 4.10 gears. 
  • Less torque for towing. 

This video demonstrates the difference in cruising speed RPMs between 3.73 and 4.10 gears: 1m2Val_bYouTube · May 29, 2020
How to choose

• Choose 4.10s if: Your priority is performance, and you want a vehicle that feels quick off the line. They are also a good choice if you frequently tow heavy loads. 
• Choose 3.73s if: Your priority is fuel economy and comfortable, quiet highway cruising. They are a better all-around choice for a daily driver or a vehicle that spends most of its time on the open road. 

What's the best gear ratio for highway driving?

The best gear ratio for highway driving is typically a numerically lower one to keep engine RPMs low, which improves fuel economy and reduces noise. For a vehicle with an overdrive transmission, a ratio like 3.25 to 3.70 is often a good compromise, while a ratio around 3.42 is a common and efficient stock setting for modern vehicles. 
This video explains the basics of gear ratios and how they affect performance: 1mGearFX DrivelineYouTube · Feb 10, 2023
Common gear ratios for highway driving

• 3.25: A good choice for pure highway cruising and long road trips, especially with a non-overdrive transmission, as it keeps RPMs very low. 
• 3.42: A popular and well-balanced ratio often found in factory vehicles, offering a good blend of fuel economy and acceleration for daily driving. 
• 3.55: A good option for prioritizing fuel economy on the highway, though it sacrifices some acceleration compared to higher ratios. 
• 3.70: A strong compromise that provides a good balance between highway cruising and better acceleration for daily driving or occasional spirited driving. 

Factors to consider

• Transmission: Vehicles with an overdrive gear (where the driveshaft spins faster than the engine's output shaft) can use a numerically lower gear ratio and still achieve low highway RPMs. 
• Tire size: Taller tires require a numerically lower gear ratio to avoid excessively high RPMs at highway speeds. 
• Engine and vehicle weight: A more powerful engine or a lighter vehicle can handle a numerically higher ratio without a significant penalty to highway performance, while heavier vehicles may need numerically lower gears for better performance. 
• Driving goals:
  • Maximum fuel economy: Go with the most numerically low ratio possible. 
  • Balance of fuel economy and acceleration: Choose a ratio in the 3.55 to 3.70 range. 
  • Frequent towing or heavy loads: You will generally want a more numerically high gear ratio for more torque, but this will result in higher RPMs on the highway. 

This video explains how to choose the right gear ratio for your vehicle based on your needs: 56sLate Model Restoration (LMR)YouTube · May 18, 2025