What is my axle ratio on a Ram 1500?

Your Ram 1500's axle ratio is the gear reduction between the driveshaft and the wheels, and it varies by year, trim, and drivetrain; common options you may see include 3.21, 3.55, and 3.92, but the exact ratio for your truck can be found on the door sticker, build sheet, or rear differential tag associated with your VIN.

Understanding what the axle ratio means for a Ram 1500

The axle ratio determines how many turns the driveshaft must make to rotate the wheels once. A higher numerical ratio (for example, 3.92) provides more torque for towing and acceleration but typically lowers highway fuel economy and higher engine RPM at a given speed. A lower numerical ratio (for example, 3.21) generally improves fuel economy and highway gearing but reduces low-end torque. The right ratio depends on your truck’s intended use, engine choice, and whether you have 4x2, 4x4, or a towing package.

How this affects your truck in practice

- Towing and hauling: trucks with higher ratios tend to pull heavier loads more readily at lower speeds.

- Fuel economy and highway drive: lower ratios usually deliver better mpg on long highway trips.

- Off-road or heavy-duty use: some configurations balance torque and gearing for expected terrain or payload.

How to find your exact axle ratio

To confirm the precise axle ratio for your Ram 1500, use one or more of these sources. Before you start, gather your VIN so you can cross-check with official build data.

• Open the driver-side door jamb sticker and look for a line that reads “Axle” or “Axle Ratio.” This is the quickest in-vehicle confirmation for many models.


• Check the rear differential tag or cover stamping. Some vehicles have the ratio stamped or labeled on the differential housing.


• Review the vehicle build sheet or window sticker (Monroney label) from when the truck was manufactured. These documents list the factory axle ratio.


• Contact a Ram/Chrysler dealer with your VIN or use an online VIN decoder to retrieve the exact axle ratio for your configuration.

Conclusion: The exact axle ratio on a Ram 1500 is specific to your truck’s year, drivetrain, and options, so use these sources to confirm rather than assuming a default.

Common axle ratios by configuration (typical, not guaranteed)

Below are the axle ratios that Ram has used in various configurations for the Ram 1500. These figures can vary by year and market, so verify with the sources above for your exact truck.

• 3.21 — Often seen on base or economy-focused configurations and some 4x2 setups.


• 3.55 — A common mid-range ratio found on many mid-grade trims and a mix of 4x4/2WD models.


• 3.92 — Frequently chosen for tow-focused builds, some 4x4 versions, and trucks outfitted with heavier payload or towing packages.

Concluding: While 3.21, 3.55, and 3.92 are the most commonly encountered ratios on Ram 1500s, the exact figure for your vehicle must be confirmed via the door sticker, VIN-based build data, or the rear differential tag.

Summary

In short, your Ram 1500’s axle ratio is a vehicle-specific number that affects towing, acceleration, and fuel economy. To determine it accurately, check the door sticker, differential tag, build sheet, or VIN decode through a dealer or official service sources. If you share your year, trim, drivetrain, and VIN, I can help you pinpoint the exact ratio and discuss its practical implications for your use case.

How do you tell if you have 3.73 or 4.10 gears?

You can tell if you have 3.73 or 4.10 gears by manually counting, checking the differential cover for a tag, or finding the ratio stamped on the ring gear. The most direct method is to lift the rear wheels, rotate one tire one full revolution, and count how many times the driveshaft turns; 3.75 turns indicates 3.73 gears, while slightly over 4 turns indicates 4.10 gears.
 
This video demonstrates how to check your gear ratio by counting the driveshaft turns: 48sBent Motorsports OffroadYouTube · Sep 22, 2023
Method 1: Manual count (with the vehicle jacked up)

1. Jack up the vehicle: Safely lift the rear of your vehicle and secure it on jack stands. Ensure the wheels are off the ground. 
2. Mark the driveshaft and a tire: Place a mark on one of the rear tires and a corresponding mark on the driveshaft. 
3. Rotate the tire: Rotate the marked tire forward one full revolution. For an open differential, you may need to lift only one wheel and have someone hold the other stationary, or lift both wheels and rotate one tire twice while the other tire is on the ground. For a locked differential, lift both rear wheels and have one tire rotate once while the other rotates once in the opposite direction. 
4. Count the driveshaft turns: Count how many times the mark on the driveshaft has rotated. 
   • 3.73 gears: The driveshaft will turn approximately 3.753.753.75 times for one full tire revolution. 
   • 4.10 gears: The driveshaft will turn a little over 444 times for one full tire revolution. 

Method 2: Check the differential cover tag 

1. Locate the tag: Look for a small metal tag that is usually bolted to the differential cover. It may be on one of the bolts. 
2. Read the ratio: If the tag is still present, the gear ratio will be stamped on it. It will likely be a number like "3.73" or "4.10". 

You can watch this video to learn how to find the differential cover tag: 51sFlawed OffroadYouTube · Apr 18, 2022
Method 3: Read the ring gear stamps 

1. Locate the ring gear: This requires removing the differential cover to get a clear view of the ring gear.
2. Find the numbers: Look for two numbers stamped on the teeth of the ring gear, such as "41" and "11". 
3. Divide the numbers: Divide the larger number (teeth on the ring gear) by the smaller number (teeth on the pinion gear). 
   • 41÷11≈3.7341 divided by 11 is approximately equal to 3.7341÷11≈3.73 
   • 41÷10=4.1041 divided by 10 equals 4.1041÷10=4.10 

This video shows how to read the ring gear stamps to find the gear ratio: 46sJL LIFE OFFROADYouTube · Nov 18, 2022

How do I tell what axle ratio I have on a Ram 1500?

You can find a Ram 1500's axle ratio by checking the vehicle's window sticker or doorjamb sticker, looking for a small metal tag on the differential cover, or using the "tire and driveshaft rotation" method. The most accurate method is to count the teeth on the ring and pinion gears inside the differential.
 
Method 1: Check vehicle stickers

• Window sticker: This will be with your original paperwork from when you purchased the vehicle. Look for a "Monroney" sticker that lists the vehicle's original options, including the gear ratio. 
• Glove box or doorjamb: Some manufacturers place a sticker with the axle code or ratio inside the glove box or on the inside of the driver's side doorjamb or door frame. 
• Axle tag: Look for a small metal tag on the rear axle's differential cover. It may have the ratio stamped on it, often as a three-digit number like "355" or "392". 

This video shows how to find the axle ratio from a tag on the differential cover: 59sWebWheelerYouTube · Apr 10, 2018
Method 2: Rotate the tires and driveshaft 

• Safely lift the rear of the truck so both rear wheels are off the ground and can spin freely. 
• Mark one of the rear tires and the driveshaft with chalk or a paint marker. 
• Rotate the marked wheel one full revolution (360 degrees). 
• While the wheel completes its single rotation, count how many times the driveshaft also rotates. 
• Your axle ratio is approximately equal to the number of times the driveshaft rotated. For example, if the driveshaft spun about 3.55 times, your ratio is approximately 3.55:1. 

This video demonstrates the tire and driveshaft rotation method: 1mChris DukeYouTube · Nov 22, 2016
Method 3: Count gear teeth (most accurate, requires opening differential) 

• Locate the differential cover on the rear axle. 
• Remove the differential cover to access the gears. 
• Count the number of teeth on the large "ring gear" and the smaller "pinion gear". 
• Divide the number of teeth on the ring gear by the number of teeth on the pinion gear to get the ratio. For example, if the ring gear has 41 teeth and the pinion gear has 11, the ratio is 41÷11≈3.7341 divided by 11 is approximately equal to 3.7341÷11≈3.73. 

This video shows how to count the teeth on the ring and pinion gears: 1mWeekendHandymenYouTube · Apr 14, 2017

Does the VIN number tell you the gear ratio?

You may be able to tell the gear ratio from a vehicle's VIN by using an online VIN decoder, though not all manufacturers include this information in the VIN itself. If the gear ratio is included, it will likely be in the Vehicle Descriptor Section (VDS), which are the 4th through 8th digits of the VIN. For many vehicles, a sticker on the driver's side door jamb or on the vehicle's build sheet or owner's manual is a more reliable way to find the gear ratio. 
How to check the VIN

• Use an online VIN decoder: Enter the full VIN into a free online decoder. Some manufacturers have their own decoders, such as Mopar's decoder. 
• Look for the gear ratio code: Some VINs will have a code within the VDS that represents the gear ratio (e.g., "3731"). 
• Consult the manufacturer: If the VIN decoder doesn't provide the information, contact the vehicle manufacturer for assistance. 

Other methods to find the gear ratio

• Check the vehicle sticker: Look for a sticker on the driver's side door jamb or on the vehicle's build sheet. This sticker often contains detailed information about the vehicle's equipment, including the axle ratio. 
• Look at the differential: Some differentials have a metal tag with the gear ratio stamped on them, or there may be a sticker on the axle itself. 
• Consult your owner's manual: The owner's manual or other paperwork from the vehicle's purchase often lists the gear ratio. 

What is the 3.21 rear axle ratio?

A 3.21 rear axle ratio is a gear ratio where the driveshaft must rotate 3.21 times for every one full rotation of the rear wheels. This ratio is a standard option for many trucks, such as the Ram 1500, and is generally better for fuel economy and highway cruising, but provides less "pulling power" than more aggressive ratios like 3.92. The overall impact on performance can be offset by modern transmissions with more gears, such as an 8-speed automatic. 
You can watch this video to learn how the 3.21 gear ratio affects the performance of the Ram 1500: 1mB MasonYouTube · Jul 26, 2022
Advantages

• Better fuel economy: 3.21 gears are more fuel-efficient for daily driving, especially on the highway, because the engine operates at lower RPMs. 
• Quieter highway cruising: This ratio is well-suited for comfortable, long-distance highway driving. 
• Good for lighter loads: When not towing, the 3.21 ratio provides adequate performance. 

Disadvantages

• Less pulling power: It can result in less off-the-line acceleration and may struggle more when towing heavy loads or climbing steep inclines. 
• Potential performance loss with larger tires: With larger aftermarket tires (e.g., 35 inches), the truck will have noticeably slower acceleration and braking performance compared to a truck with a more aggressive ratio, say Reddit users. 
• Transmission hunting: The transmission may shift more frequently between gears when towing or under strain, note some YouTube commenters. 

This video demonstrates how the 3.21 gear ratio performs when towing a car trailer: 1m4-LOWYouTube · May 30, 2023
Who should choose the 3.21 ratio?

• Drivers who prioritize fuel efficiency and spend most of their time on the highway. 
• Those who plan to use their truck for general-purpose driving and only occasionally tow lighter loads. 
• Drivers who will be using the factory-sized tires that the vehicle came with.