Mini-Z MR-03 vs MR-04: Which Chassis to Buy in 2026
MR-03 costs less with deeper parts availability. MR-04 has lower CG and newer electronics. Which chassis wins for your budget and track style in 2026.
MR-03 · MR-04
If you’re getting into 1/28 scale racing in 2026, you have two main choices from Kyosho: the legendary MR-03 platform (specifically the EVO/EVO2 chassis) or the newer MR-04EVO2.
The MR-03 has been the gold standard for over a decade. The MR-04 is the new flagship, designed to lower the center of gravity and improve cornering speed.
But “newer” doesn’t always mean “buy this one immediately.” If you’re still weighing whether Mini-Z is the right hobby, read why Mini-Z is the best entry point to RC first. Otherwise, let’s break down the differences, the costs, and who should buy which car.
Prices shown in USD. Check your local retailer for current regional pricing.
Key Differences at a Glance
| Feature | MR-03 EVO / EVO2 | MR-04 EVO2 |
|---|---|---|
| Motor Position | Higher CG | Lower CG (Motor mount redesigned) |
| Front Suspension | Standard Kingpin Coil | Redesigned Knuckles & Kingpins |
| Electronics | FHSS / ASF / MHS | FHSS / Noble NB4 / Futaba Support |
| Sensor Support | Sensorless Brushless | Sensored Brushless (Smoother low end) |
| Width Options | Narrow (N) & Wide (W) | Narrow (N) & Wide (W) - New offsets |
| Price (Chassis) | around $170 - $200 USD | around $230 - $260 USD |
1. Handling & Geometry
The MR-04 was built to fix the MR-03’s main weakness: high center of gravity (CG). The batteries sit lower, and the motor mount is redesigned to drop the motor closer to the ground.
- Cornering: The MR-04 feels more “planted” out of the box. It has less tendency to traction roll on high-grip RCP tracks.
- Steering: The MR-04 uses a new knuckle design that changes the scrub radius. It feels more direct but requires specific MR-04 front springs and knuckles. MR-03 front springs do not fit the MR-04.
The MR-03 is a solved problem. With a brass front bulkhead and the right tires, it handles beautifully. It’s “tippier” than an MR-04, but 10+ years of setup guides exist to tame it. On both platforms, the T-plate is the primary rear suspension tuning lever. Stiffness selection matters more than most beginners expect.
2. Parts Compatibility (The Big One)
This is where the decision gets tricky.
What Fits Both?
- Bodies (mostly - check motor mount clearance)
- Wheels (Standard offsets, though MR-04 sometimes needs different offsets for the same body)
- Rear Tires (Radial/Slicks)
- Differentials (Ball diffs / Gear diffs usually swap)
- Rear Suspension (T-Plates are generally cross-compatible or adaptable)
What DOES NOT Swap?
- Front Springs: Different lengths/diameters.
- Knuckles: Totally different geometry.
- Motor Mounts: MR-04 mounts are specific to the chassis layout.
- Bearings: MR-04 uses smaller/different bearings in the front knuckles.
- Sensored Motors: You need an MR-04 specific harness/ESC to run sensored.
Warning: If you have a box full of MR-03 spares, very few of your front-end parts will work on an MR-04.
3. Electronics & Radio
Both chassis use Kyosho’s receiver unit system. You buy the chassis without a receiver, then plug in the module for your radio (Flysky Noble NB4, Futaba, KO Propo, or Kyosho Syncro).
The MR-04 difference: It supports Sensored Brushless Motors.
- Sensorless (MR-03): Can “cog” or stutter at very low speeds.
- Sensored (MR-04): Butter-smooth startup and throttle control, essential for technical tracks or drifting (though this is a RWD race chassis, not a drifter).
Cost to Race-Ready
MR-03 Path:
- Chassis: around $180 USD: → Kyosho MR-03EVO Chassis Set on Amazon
- Radio Module: around $50 USD
- Tires/Wheels: around $25 USD: → Kyosho Mini-Z Radial Tires 30° on Amazon
- Bearings: around $15 USD: → FastEddy Sealed Bearing Kit for MR-03 on Amazon
- Total: around $270 USD (plus transmitter)
MR-04 Path:
- Chassis: around $240 USD: → Kyosho MR-04EVO2 Chassis Set on Amazon
- Radio Module: around $50 USD
- Tires/Wheels: around $25 USD (same Kyosho 30° radials as MR-03 path above)
- Total: around $315 USD (plus transmitter)
The price gap isn’t huge, but the availability gap can be. MR-04 parts are sometimes out of stock as manufacturers ramp up.
Final Recommendation
Get the MR-03 if:
- You are buying used (great deals available).
- You want to build a specific “weird” wheelbase or narrow car (more aftermarket support).
- You are on a strict budget.
→ See the MR-03 Upgrade Guide for the full build path once you have it.
Get the MR-04 if:
- You want the best performance potential right now.
- You already own a high-end radio (Noble NB4 or Futaba 10PX).
- You hate “cogging” and want that sensored smooth feel.
→ See the MR-04 Upgrade Guide for platform-specific setup notes.
Whichever platform you choose, the First 5 Upgrades apply to both. Bearings, tires, and T-plate are the foundation. Working with a limited budget? The Best Budget Setups Under $50 covers both platforms. Planning to use the car for both racing and casual driving? The Racing vs Bashing Setup guide covers how tire strategy, gearing, and gyro settings change completely depending on what you’re asking the car to do, and how the MR-03 and MR-04 respond differently to those changes. Once you’re past the basics and comparing notes at club night, the How to Read a Setup Sheet guide explains every field you’ll encounter (T-plate flex, spring rates, diff preload, camber clicks) so borrowing a fast driver’s baseline actually gets you somewhere.
Product images courtesy of Kyosho.