6 I (GG) vs C-Class W203: which is better?
Mazda 6 I (GG) (2002–2008) vs Mercedes-Benz C-Class W203 (2000–2007): specs, fuel economy, tax and common problems.
Mazda 6 I (GG)Specifications
| Mazda 6 I (GG) | Mercedes-Benz C-Class W203 | |
|---|---|---|
| Production years | 2002–2008 | 2000–2007 |
| Body | sedan | sedan |
| Fuel | petrol | petrol |
| Engines | 2.0 | 1.8 Kompressor (C180) |
| Power, up to | 141 hp | 143 hp |
| Torque, up to | 181 Nm | 220 Nm |
| Gearbox | automatic | automatic |
| Drive | front-wheel drive | rear-wheel drive |
| Length | 4 670 mm | 4 526 mm |
| Width | 1 780 mm | 1 728 mm |
| Height | 1 435 mm | 1 426 mm |
| Wheelbase | 2 675 mm | 2 715 mm |
| Fuel tank | 64 L | 62 L |
| KZ tax 2026 (car under 10 years) | ≈ 16 475 ₸ | ≈ 15 075 ₸ |
The better value is highlighted in green.
Pros, cons and common problems
Mazda 6 I (GG)
Pros
- Conventional automatic, no robotized gearbox or CVT
- Sold in all major markets of the region — parts and mechanics available
Cons
- Mazda Z6 / LF / FS engine: oil consumption at high mileage
Engine (Mazda Z6 / LF / FS): oil consumption at higher mileage; carbon buildup and ring coking.
Mercedes-Benz C-Class W203
Pros
- Gearbox Mercedes 722.x (4–5-speed automatic): very reliable
- Sold in all major markets of the region — parts and mechanics available
Cons
- Engine Mercedes M271 (1.8): timing chain stretch
- Gearbox Mercedes 722.x (4–5-speed automatic): leaking connector adapter and wiring
Engine (Mercedes M271 (1.8)): timing chain stretch; oil leaks from the heat exchanger and oil separator.
Gearbox (Mercedes 722.x (4–5-speed automatic)): very reliable; leaks from the connector adapter and wiring.
Which one to choose
- 6 I (GG) — if you care more about: fuel tank.
- C-Class W203 — if you care more about: power, torque, wheelbase, kz tax 2026.
The condition of a specific car matters more than the model: check the service history and get the engine and gearbox inspected before buying.
FAQ
Which is more powerful: 6 I (GG) or C-Class W203?
6 I (GG): up to 141 hp, C-Class W203: up to 143 hp.
What is the vehicle tax in Kazakhstan?
For 2026, for a car under 10 years old: 6 I (GG) — about 16 475 ₸, C-Class W203 — about 15 075 ₸ (base engine). A 0.7 factor applies to cars aged 10–20 years and 0.5 to cars over 20.