Question: How to Find Gear Ratio by VIN (Ultimate Guide)

Does finding your car’s gear ratio seem like a mystery?

Many drivers struggle to determine this ratio to know how their vehicles will perform in various situations. The gear ratio can help you determine how your vehicle accelerates, the amount of fuel it consumes, and more.

Luckily, you don’t need a secret sauce to find this ratio. With the help of your Vehicle Identification Number (VIN), it’s easier to find your car’s gear ratio.

Our guide discusses how to find gear ratio by VIN. You’ll also know other methods you can use to come up with your gear ratio.

Answer: Gear Ratio Explained

Before finding your gear ratio by VIN, let’s see what the gear ratio in your car means. Typically, a gearbox with 1-5 gears has two different-sized cogs. These gears attach to one of these cogs to provide different ratios.

There’s a cog attached to your car’s engine side known as the input gear. The other cog linked to the road wheel side of your car’s gearbox is called the output gear.

When in 1st gear, a car will need a higher gear ratio to get it moving from a standstill. In this case, the input gear will be smaller than the output gear, resulting in a higher gear ratio. Such a ratio allows the engine to rotate more times than the wheels, providing more power (torque).

On the other hand, when in 5th gear, a car requires less torque because it’s already in motion. Here, the input gear will be larger than the output gear, providing the lowest gear ratio.

Question: What is a VIN?

The Vehicle Identification Number (VIN) is a 17-digit code comprising letters and numbers. As its name implies, VIN helps identify a specific vehicle. With a VIN, you can tell a vehicle’s make, model, year, engine size, and gear ratio.

The VIN code is grouped into the following three sections:

  • WMI or World Manufacturer Identifier
  • VDS or Vehicle Descriptor Section
  • VIS or Vehicle Identification Section

Here’s a breakdown of the VIN code to help you understand what the letters and digits imply:

  • The first digit: This digit denotes the vehicle manufacturer’s country.
  • Second digit: This digit represents the manufacturer.
  • The initial letter: This letter indicates the vehicle’s category or kind.
  • 4th to 8th characters: These characters provide the vehicle’s information regarding its make, model, gear ratio, transmission, and more.
  • The last number: This number represents the manufacturer’s security code.
  • 10th digit: This digit indicates the vehicle’s production year.
  • 11th character: It indicates the vehicle’s assembly line.
  • The remaining digits: These digits represent the unique car production number.

An online VIN checker or professional mechanic can help you decode your car’s VIN. But first, you must know where to locate this VIN in your vehicle. The most common areas to find the VIN plate in your car include:

  • The dashboard on the driver’s side
  • Under the hood (usually the front engine block)
  • A sticker inside the driver’s side door
  • A vehicle’s registration document

After locating the VIN, you can decode it to find your vehicle’s gear ratio.

Answer: How to Find Gear Ratio by VIN

The VIN code provides the easiest way to find your vehicle’s gear ratio. But that’s only possible if the manufacturer includes it there.

As mentioned earlier, the VDS of a VIN holds critical information about your car, including its gear ratio. The VDS is the 4th to 8th digits of the VIN. An online VIN decoder like the NHTSA’s VIN Decoder, Edmunds.com, or Decode This can help you know if the VDS includes a car’s gear ratio.

But we’ll explain how to decode the digits representing your car’s gear ratio. If you find a code like 3501 on the VDS as the gear ratio, it means the engine rotates 3.50 or 3½ times per complete wheel spin. So, the gear ratio should be indicated as 3:50:1

What if you can’t find the gear ratio on the VIN code or your car’s glove box? In such a case, you’ll need to work out this ratio manually.

Answer: How to Calculate Gear Ratio

Below are two methods you can use to determine your vehicle’s gear ratio without relying on VIN.

Count Your Wheel Turns

You can work out your vehicle’s gear ratio by counting the number of times your rear wheel rotates per driveshaft turn. To get the correct figure, you’ll need to follow these steps:

  1. Block your front wheels to prevent them from moving.
  2. Jack up your vehicle’s rear (the rear tires must be off the ground).
  3. Put your vehicle in neutral (the car must be off).
  4. Put a visible mark on the driveshaft.
  5. Rotate the rear wheel – one full rotation – towards the front of your vehicle. While rotating the wheel, check the driveshaft and take note of how many times it turns per wheel rotation. The visible mark on the driveshaft should help you know when there’s a full turn.

The number of rotations you’ll count from the driveshaft should help you determine the gear ratio. Here are examples to help you know your ratio:

  • 2¾ rotations (2.73 gears) = 2:73:1
  • Just past 3 rotations (3.08 gears) = 3:08:1
  • 3¼ rotations (3.27 gears) = 3:27:1
  • 3½ rotations (3.50 gears) = 3:50:1
  • 3¾ rotations (3.73 gears) = 3:73:1
  • Just under 4 rotations (3.90 gears) = 3:90:1
  • Just past 4 rotations (4.10 gears) = 4:10:1

Divide the Ring and Pinion Teeth

Another accurate method to calculate your gear ratio is dividing the number of ring gear teeth by the number of pinion gear teeth. In this case, you must remove the differential cover first. Then, count the ring gear teeth and pinion gear teeth.

If you can’t determine the gear ratio using the above methods, consult your car’s owner’s manual. Alternatively, contact your vehicle manufacturer’s customer service. Provide them with your vehicle’s VIN, and they’ll tell you what your gear ratio is.

Question: Why Find Your Car’s Gear Ratio?

Now that you know how to find gear ratio by VIN and alternative methods, why is it important to determine this ratio? Below are the reasons why determining gear ratio is vital.

  • Know your vehicle’s towing capacity: A higher gear ratio translates to more towing capacity. For example, a truck with a 4:10:1 gear ratio has more towing capacity than one with 3:15:1.
  • Determine vehicle’s speed: More towing capacity means low top speed. That’s why a car whose gear ratio is 2:73:1 is faster than a truck with 4:10:1.
  • Determine vehicle’s fuel economy: High gear ratio and more towing capacity come with lower fuel economy.
  • Make informed upgrade decisions: When upgrading your car gearbox, you’ll want to know the gear ratio to ensure you maintain an optimized performance.

Final Thoughts

You now know how to find gear ratio by VIN. If you’ve located the VIN in your car, check the VDS portion to know your car’s gear ratio. A free online VIN decoder can help you decode each letter and digit. But what if the manufacturer didn’t include the gear ratio in your VIN?

In this case, you can determine the ratio by counting the wheel turns or dividing the ring and pinion teeth. Still unable to find this ratio? If so, check the manual or contact the manufacturer’s customer service for help.