Upgrading your 4×4 with bigger tires is exciting – it looks great and performs better off-road. But many owners quickly notice a problem: the vehicle feels sluggish, loses acceleration, and fuel economy drops.
The solution? Differential re-gearing. Don’t worry if it sounds technical – here’s a simple explanation.
Simple Guide for 4×4 Owners
What is a Differential?
Your vehicle’s differentials are gearboxes in the axles. They:
- Send power from the engine to the wheels
- Allow wheels to spin at different speeds when cornering
- Contain ring and pinion gears that set your gear ratio
What is a Gear Ratio?
The gear ratio shows how many times the driveshaft spins compared to one wheel rotation.
- Lower ratio (3.55, 3.73): Better fuel economy, less torque.
- Higher ratio (4.56, 4.88): More pulling power and torque, less top speed.
Why Re-gear?
When you install larger tires, the factory gear ratio no longer matches. This causes:
❌ Sluggish acceleration
❌ Poor fuel efficiency
❌ Constant transmission shifting
❌ Stress on engine and drivetrain
Re-gearing means replacing the ring and pinion gears with a ratio that matches your new tire size.
Example: Bigger Tires, New Gears
- Stock Jeep: 3.73 gears + 31” tires → balanced performance
- Upgrade: 35” tires → power loss, sluggish on hills
- Solution: Regear to 4.56 or 4.88 → restores original performance
Benefits of Re-gearing
✅ Restores lost power after bigger tires
✅ Improves fuel economy
✅ Reduces stress on transmission & engine
✅ Better off-road performance and hill climbing ability
Recommended Gear Ratios for Tire Sizes
Use this chart to find the best ring and pinion gear ratio for your Jeep, SUV, or 4×4 after upgrading tires:
| Tire Size (inches) | Best Gear Ratio (Manual) | Best Gear Ratio (Automatic) | Notes |
| 31″ (stock size) | 3.55 – 3.73 | 3.73 – 4.10 | Factory setup usually fine |
| 33″ | 4.10 – 4.56 | 4.56 | Noticeable improvement |
| 35″ | 4.56 – 4.88 | 4.88 | Restores power & drivability |
| 37″ | 4.88 – 5.13 | 5.13 | Strongly recommended |
| 40″ | 5.13 – 5.38 | 5.38 | For extreme off-road builds |
Easy Analogy: Like Riding a Bicycle
Think of gears like a bicycle:
- Wrong gear uphill = heavy, slow pedaling (big tires without regearing)
- Right gear uphill = smooth and powerful (after regearing)
That’s exactly what happens to your 4×4 – re-gearing puts you back in the right gear.
Final Thoughts
Differential re-gearing may sound complex, but it’s simply about matching your gear ratio to your tire size. If your 4×4 feels sluggish after a tire upgrade, regearing with the right ring and pinion set will restore power, fuel efficiency, and off-road performance.
👉 At Offroad Zone Armenia, we offer professional re-gearing kits, ring and pinion sets, and installation services to keep your 4×4 running at its best.
