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What is the difference between 3.73 and 4.10 gear ratio?

The gear ratio of a vehicle's differential is a crucial factor that affects its performance and fuel efficiency. The difference between a 3.73 and a 4.10 gear ratio can have significant implications for how a vehicle behaves on the road. In this article, we'll explore the key distinctions between these two gear ratios and how they impact a vehicle's driving characteristics.

What is Gear Ratio?

Gear ratio refers to the relationship between the number of teeth on the ring gear and the number of teeth on the pinion gear in a vehicle's differential. This ratio determines how many times the driveshaft must rotate for the wheels to make one complete revolution. A higher gear ratio, such as 4.10, means the wheels will rotate more times for each rotation of the driveshaft, providing more torque and acceleration but lower top-end speed. Conversely, a lower gear ratio, like 3.73, results in fewer wheel rotations per driveshaft rotation, sacrificing some low-end torque for higher top-end speed.

Comparing 3.73 and 4.10 Gear Ratios

The primary differences between a 3.73 and a 4.10 gear ratio are as follows:

Acceleration and Torque: The 4.10 gear ratio provides more low-end torque and acceleration, making the vehicle feel more responsive off the line and during passing maneuvers. The 3.73 ratio, on the other hand, sacrifices some of this low-end power for higher top-end speed.

Top Speed: Vehicles with a 3.73 gear ratio will generally achieve a higher top speed compared to those with a 4.10 ratio, as the lower gear ratio allows the engine to reach higher RPMs before the vehicle reaches its maximum velocity.

Fuel Efficiency: The 3.73 gear ratio is typically more fuel-efficient than the 4.10 ratio, as the engine operates at lower RPMs at a given speed, reducing fuel consumption.

The choice between a 3.73 or 4.10 gear ratio ultimately depends on the intended use of the vehicle. If you prioritize acceleration and low-end power, the 4.10 ratio may be the better option. However, if you value top-end speed and fuel efficiency, the 3.73 ratio may be the more suitable choice.

Does a 4.10 axle ratio better for towing on a RAM?

With the available 4.10 axle ratio, it can tow between 16,920 lbs (Crew Cab 8′ Bed 4×4) and 17,750 lbs (Regular Cab 8′ Bed 4×2). The available 6.7L Cummins I6 Turbo Diesel engine can tow between 14,630 lbs (Mega Cab 6'4″ Bed 4×4) and 20,000 lbs (Crew Cab 8′ Bed 4×2).

What is a 3.73 axle ratio good for?

3.73 gears are a good compromise for improved off-the-line acceleration and towing while still providing reasonable highway performance and fuel economy compared to numerically higher gears like 4.10s. They are ideal for a daily driver that needs more power, particularly for towing or off-road use, but where maintaining highway fuel efficiency is still important. They are also a popular upgrade to compensate for larger tires and to make a vehicle feel more powerful.
Key benefits of 3.73 gears

Improved acceleration and torque: They provide a noticeable boost in off-the-line performance, making the vehicle feel more responsive.
Better towing and hauling: A higher gear ratio means more torque is sent to the wheels, making it easier to tow heavy loads.
Compensation for larger tires: They can be used to bring a vehicle's gearing back in line after installing larger tires, which would otherwise hurt acceleration and performance.
Versatility: They offer a good balance between performance and fuel efficiency, making them suitable for both street and occasional track or off-road use.

Considerations

Higher RPMs at highway speeds: Compared to lower gear ratios (like 3.55 or 3.08), a 3.73 gear will result in slightly higher engine RPMs at the same road speed, which can slightly decrease fuel economy on very long highway trips.
Trade-offs: Choosing 3.73 gears means a slight trade-off in top-end speed and fuel economy compared to lower gear ratios.

Is it better to have a higher or lower gear ratio?

Neither a higher nor a lower gear ratio is inherently better; it depends on the application. A lower gear ratio (numerically higher) provides more torque for better acceleration, ideal for starting from a stop, towing, or off-roading. Conversely, a higher gear ratio (numerically lower) provides more speed and better fuel efficiency, making it better for highway cruising.
Lower gear ratio (e.g., 4.11:1)

Benefits: More torque, faster acceleration, better for towing and climbing hills.
Drawbacks: Slower top speed, higher engine RPMs at highway speeds, which can decrease fuel economy.

Higher gear ratio (e.g., 3.08:1)

Benefits: Better fuel economy at highway speeds, lower engine RPMs.
Drawbacks: Slower acceleration from a stop, less torque for heavy loads.

Finding the right balance

Most vehicles use a transmission with a range of gear ratios to balance these needs, using lower gears for starting and higher gears for cruising.
For example, a vehicle might use a numerically high ratio like 4.11:1 in first gear for starting and a numerically low ratio like 3.25:1 in its highest gear for highway driving.

Which rear-end gear ratio is best?

There is no single "best" rear end gear ratio; the ideal choice depends on your vehicle's purpose, with lower numbers (e.g., 3.253.253.25) being better for highway fuel economy and top speed, and higher numbers (e.g., 4.104.104.10) being better for acceleration and towing. For a balanced daily driver that handles occasional hauling, a ratio like 3.553.553.55 is a popular and good compromise.

Gear ratio comparison

Gear Ratio	Numerical Value	What it's best for
Numerically lower ratios	e.g., 3.25,3.55,3.733.25 comma 3.55 comma 3.733.25,3.55,3.73	Highway driving, fuel economy, and top speed. A lower number means the engine will run at lower RPMs at highway speeds.
Numerically higher ratios	e.g., 4.11,4.56,4.884.11 comma 4.56 comma 4.884.11,4.56,4.88	Acceleration, towing, and off-roading. A higher number means more torque and faster acceleration from a stop, but higher RPMs at highway speeds.
Balanced ratios	e.g., 3.553.553.55 to 3.733.733.73	A compromise for daily driving. These ratios are often a good middle ground, providing adequate performance for daily use while still offering reasonable fuel efficiency on the highway.

For maximum fuel economy and highway cruising: Choose a numerically lower ratio, such as 3.253.253.25 or 3.553.553.55.
For better acceleration and hauling: Choose a numerically higher ratio, like 4.114.114.11 or 4.564.564.56.
For a mix of both: A ratio in the middle, like 3.553.553.55 or 3.733.733.73, is a great all-around choice for a vehicle that sees both city and highway use with occasional hauling.
For a drag strip or autocross: You will likely want a higher numerical gear ratio, such as 4.114.114.11 or higher, to keep the engine in its power band during acceleration.
For a heavy-duty truck: Consider the manufacturer's recommendations for towing capacity, which are often matched to specific gear ratios.

Kevin Bennett

Company Owner

Kevin Bennet is the founder and owner of Kevin's Autos, a leading automotive service provider in Australia. With a deep commitment to customer satisfaction and years of industry expertise, Kevin uses his blog to answer the most common questions posed by his customers. From maintenance tips to troubleshooting advice, Kevin's articles are designed to empower drivers with the knowledge they need to keep their vehicles running smoothly and safely.