3.73 vs 4.10 Axle Ratios: Which Is Better?

It depends on how you use the vehicle. A 4.10 axle ratio delivers roughly 10% more wheel torque than a 3.73, improving acceleration, towing, and off‑road control, but it raises highway RPM by about 150–250 rpm at 70 mph and can trim fuel economy. A 3.73 is typically the better pick for mixed driving and frequent highway use, especially on modern 8–10‑speed transmissions or with stock-size tires.

What an Axle Ratio Does

The axle (final drive) ratio multiplies the transmission’s output torque before it reaches the wheels. Higher numerical ratios (like 4.10) trade engine speed for torque, helping you get moving faster or maintain pace under load. Lower numerical ratios (like 3.73) keep RPM lower at a given road speed, favoring quieter cruising and potentially better fuel economy.

How 3.73 and 4.10 Differ in Practice

Switching from 3.73 to 4.10 increases wheel torque by about 9.9% (4.10 ÷ 3.73). The trade-off is proportionally higher engine speed in the same gear at the same road speed. With today’s transmissions—many with deep first gears and multiple overdrive ratios—the penalty of 4.10 on the highway is smaller than it used to be, but it still exists.

When 3.73 Is Usually the Better Choice

Choose 3.73 when your priorities tilt toward overall efficiency and relaxed cruising without a heavy, constant load.

• Daily driving with regular highway miles
• Stock or mild tire sizes (roughly 29–33 inches)
• Modern 8–10 speed transmissions that already provide strong launch gearing
• Turbocharged engines or broad-torque powertrains that don’t need extra final-drive help
• Desire for lower cabin noise and better highway fuel economy

In these scenarios, 3.73 typically offers a balanced blend of pep and economy, taking advantage of multi-speed transmissions to fill any low-speed gaps.

When 4.10 Is Usually the Better Choice

Pick 4.10 when you consistently need more low-speed torque and tighter control, or when larger tires and weight work against you.

• Frequent heavy towing or hauling near GVWR/GCWR
• Oversized tires (35 inches and up), which effectively “tall” the gearing
• Off-road crawling, steep grades, or soft surfaces where low-speed control matters
• Short-hop city driving or performance-focused builds seeking quicker acceleration
• Older 4–6 speed transmissions that lack very deep first/overdrive ratios

In these use cases, 4.10 supplies the extra leverage to keep the engine in its power band, reduces gear hunting, and improves drivability under load.

Highway RPM Comparison at 70 mph

Engine speed depends on overall gearing (transmission top gear × axle ratio) and tire diameter. As a rule of thumb with 33-inch tires: on a 6-speed auto with a 0.67 top gear, 3.73 turns roughly 1,780 rpm at 70 mph, while 4.10 is about 1,960 rpm; on a 10-speed with ~0.63 top gear, 3.73 is about 1,675 rpm and 4.10 about 1,845 rpm. The common formula is RPM = (MPH × transmission top gear × axle ratio × 336) ÷ tire diameter (inches).

Real-World Fuel Economy Impact

Expect a modest hit with 4.10s—often around 0.5 to 1.5 mpg on the highway versus 3.73s, depending on vehicle, speed, and wind/tire setup. In city driving, the difference may be smaller, especially if the shorter gearing prevents lugging and allows earlier upshifts. EPA window-sticker differences for trucks with alternative axle ratios typically range from zero to about 1 mpg, but your results depend on load and speed.

Towing and Ratings

Manufacturers often rate higher tow capacities with numerically higher axle ratios because of improved launch and grade performance. However, with modern 10-speed transmissions and powerful engines, some trims show little difference in rated capacity across ratios. Always confirm the exact tow rating from the vehicle’s door jamb and the maker’s towing guide for your configuration.

Tire Size and “Effective” Gearing

Bigger tires lower your effective axle ratio because each revolution covers more ground. You can estimate the change by multiplying the axle ratio by the stock tire diameter, then dividing by the new tire diameter. For example, moving from a 31-inch to a 35-inch tire on a 3.73 axle feels like dropping to about 3.30. The same tire on a 4.10 feels like about 3.63.

Quick Decision Guide

Use these checkpoints to match the ratio to your real-world use case.

1. If you tow/haul heavy or drive in steep terrain regularly, choose 4.10.
2. If you run 35-inch or larger tires, choose 4.10; with 33-inch tires, it depends on load and transmission; with stock tires, 3.73 is usually fine.
3. If you drive long highway distances at steady speeds, choose 3.73.
4. If you have an 8–10 speed transmission and don’t carry heavy loads, 3.73 is typically optimal.
5. If you have a 4–6 speed transmission or want snappier acceleration from a naturally aspirated engine, 4.10 will feel stronger.

Following these steps aligns the axle ratio with how the vehicle is actually used, minimizing compromises.

Bottom Line

Neither ratio is universally “better.” 3.73 is the sensible default for mixed driving and highway efficiency, especially on modern multi-speed automatics and near-stock tires. 4.10 shines when you need maximum low-speed torque—heavy towing, off-road work, or oversized tires—accepting a small highway RPM and fuel-economy trade-off in return for stronger, more controllable performance under load.

Summary

Choose 3.73 for balanced daily driving and highway economy; choose 4.10 for stronger launch, towing, off-road control, and big tires. The right answer depends on your transmission, tire size, engine characteristics, terrain, and how much time you spend under load versus cruising.

Are 373 gears good for racing?

Yes, 3.73 gears are often good for racing because they provide a good balance of improved acceleration and reasonable top speed for many performance-oriented vehicles, but whether they are “good” depends on the specific vehicle, its powerband, transmission, and intended racing application. Higher gear ratios like 3.73 deliver more torque to the wheels for quicker launches, but they increase engine RPM at highway speeds, which can limit top speed and fuel economy compared to lower gear ratios.
 
Benefits for Racing

• Improved Acceleration: A higher number for the gear ratio (like 3.73) transfers more torque to the drive wheels, resulting in faster acceleration from a stop. 
• Faster Shifting: The improved acceleration can make the vehicle feel more punchy, and the gears will shift more quickly. 
• Good for Drag Racing: For drag strip racing or 1/4 mile runs, 3.73 gears are often suitable as they provide the necessary acceleration without running out of gear too early. 

Considerations

• Vehicle-Specific: Opens in new tabThe ideal gear ratio depends heavily on the vehicle’s engine powerband, vehicle weight, and tire size. 
• Balance of Acceleration and Top Speed: Opens in new tab3.73 gears are often considered an all-around compromise, offering a significant boost in acceleration over lower gears but with less top speed than lower ratios. 
• Engine RPM: Opens in new tabHigher RPMs are needed to maintain a certain speed, which can increase fuel consumption and potentially lead to higher oil temperatures. 
• Transmission Type: Opens in new tabA close-ratio transmission, common in manual cars, might experience too many shifts with 3.73 gears for some driving scenarios. 
• Type of Racing: Opens in new tabFor drag racing, 3.73 gears can be ideal. However, for road course racing or roll racing, a different ratio might be better depending on the car’s powerband and the length of the track, according to a Facebook post. 

What gear ratio is best for performance?

For High-Performance Cars: Ratios like 4.10 to 4.30 are common. For Street Cars: Ratios around 3.73 to 4.10 can provide a balance between performance and drivability. Ultimately, finding the optimal ratio often requires testing and tuning based on your specific vehicle setup and performance goals.

What is a 3.73 axle ratio good for?

3.73 gears are good for improving a vehicle’s acceleration and towing power by increasing low-end torque, making them a good option for off-the-line performance in sports cars or for heavy-duty towing in trucks. While they provide better acceleration than higher gears (lower number), 3.73s sacrifice some top-end speed and fuel economy compared to lower gears (higher number), such as 3.55 or 3.31. 
Benefits of 3.73 Gears

• Improved Acceleration: A higher numerical gear ratio like 3.73 provides more torque to the wheels, resulting in quicker acceleration from a standstill and a more “punchy” feel. 
• Better Towing Capacity: For trucks, 3.73 gears offer more pulling power and a mechanical advantage for moving heavy loads, making them ideal for towing. 
• Agile Performance: In sports cars or trucks, 3.73 gears can provide a more aggressive feel and improved handling in certain driving conditions. 

Considerations

• Reduced Fuel Economy: Because the engine needs to work harder to achieve the same road speed, fuel efficiency decreases with a higher numerical gear ratio. 
• Lower Top Speed: A 3.73 gear ratio will result in a lower overall top speed compared to vehicles with lower (numerically higher) gear ratios, as the engine reaches its RPM limit sooner. 
• Higher Engine RPMs: The engine will operate at higher RPMs at any given road speed, which also contributes to lower fuel mileage and can increase oil temperatures. 

In Summary
Choose 3.73 gears if your priority is enhanced acceleration, better towing capability, or a more spirited driving experience. If your primary goal is highway cruising and maximizing fuel economy, a numerically lower gear ratio, such as 3.55, would be a better choice.

Should I get 3.73 or 4.10 gears?

Neither 4.10 nor 3.73 is universally “better”; rather, 4.10 gears are better for acceleration and torque, while 3.73 gears are better for highway fuel economy and top speed. Choose 4.10 if your priority is quicker starts and better performance in city driving or towing, and choose 3.73 if you prioritize lower highway engine speeds, better fuel efficiency on the highway, and higher top speed. 
Choose 4.10 gears if:

• You want better acceleration: Opens in new tab4.10s provide more torque to the wheels, resulting in faster acceleration from a standstill. 
• You drive mainly in the city: Opens in new tab4.10s can improve city driving by reducing engine lugging and downshifting. 
• You plan to tow heavy loads: Opens in new tabThe increased torque from 4.10s makes them a good option for towing. 
• You have an automatic transmission: Opens in new tabSome users suggest 4.10s are a great choice for automatic transmissions to improve performance, notes Reddit users. 

Choose 3.73 gears if:

• You do a lot of highway driving: The higher number for highway driving offers better fuel economy and more comfortable cruising. 
• You want a good balance: 3.73s provide an aggressive feel off the line but still allow for comfortable highway driving, making them a versatile “all-around” option. 
• You are concerned about noise and vibration: Lower engine RPMs at highway speeds with 3.73 gears can lead to a quieter and smoother ride. 
• You want a higher top speed: 3.73 gears allow the engine to reach a higher top speed before hitting its redline.