When comparing the maintenance costs of kei cars and standard cars, kei cars are overwhelmingly more advantageous in three key areas: taxes, insurance, and fuel costs.
Here is a breakdown of the main maintenance cost items.
1. Taxes
Taxes are where the biggest difference between a kei car and a standard car lies.
- Automobile Tax (by Type)
- Kei Car: A flat rate of ¥10,800 per year (for private-use four-wheeled kei cars registered on or after April 1, 2015).
- Standard Car: The tax amount is determined by engine displacement. The larger the displacement, the higher the tax. Even the cheapest category (1.0L or less) costs ¥25,000 per year, and for a 1.0L to 1.5L engine, it is ¥30,500, which is about 2 to 3 times more than a kei car.
- Automobile Tonnage Tax
- Kei Car: Regardless of the car’s weight, the tax is ¥6,600 for two years (excluding vehicles eligible for eco-car tax reduction).
- Standard Car: The tax is added for every 0.5 tons of vehicle weight. For example, a 1.5-ton car costs ¥24,600 for two years, which is about four times more than a kei car.
| Item | Automobile Tax (by Type) | Automobile Tonnage Tax |
| Payment Timing | Once a year (May) | At new car purchase and during vehicle inspection (every 2-3 years) |
| Tax Amount Based On | Engine displacement | Vehicle weight and age |
| Recipient | Prefectural or municipal government | National government |
2. Insurance
- Voluntary Insurance: Kei cars tend to have lower premiums because they have a lower accident rate and the repair and compensation costs in an accident are generally cheaper. The annual difference is often in the range of several thousand to tens of thousands of yen.
- Mandatory Liability Insurance: There isn’t a significant difference between a kei car and a standard compact car, but the kei car is slightly cheaper.
3. Fuel Costs
- Fuel Efficiency: Since kei cars are lightweight and have small engines, many models offer better fuel efficiency than standard cars. The greater your annual mileage, the larger the difference in fuel costs will be.
4. Vehicle Inspection and Maintenance Costs
- Vehicle Inspection (Shaken) Costs: Since the statutory costs paid during the inspection (automobile tonnage tax, mandatory liability insurance, stamp fees) are lower for a kei car, the overall inspection cost is also cheaper.
- Maintenance Costs: Parts for kei cars are smaller, and their structure is relatively simple, so replacement part costs and labor fees tend to be lower than for standard cars.
A 1-Year Maintenance Cost Simulation
Let’s do a concrete 1-year simulation comparing the maintenance costs of a kei car and a standard car based on common conditions.
[Simulation Assumptions]
- Car Types:
- Kei Car: A typical kei car (e.g., engine displacement of 660cc or less)
- Standard Car: A compact car (e.g., engine displacement of 1.5L, vehicle weight of 1.5t or less)
- Annual Mileage: 10,000 km
- Gasoline Price: ¥170/L
- Fuel Efficiency:
- Kei Car: 20.0 km/L
- Standard Car: 15.0 km/L
- Parking Fee: ¥10,000 per month
- Voluntary Insurance: Based on a 20-30 year old driver, new contract (6th grade), gold license, and standard coverage.
1. Taxes (for 1 year)
- Automobile Tax (by Type)
- Kei Car: ¥10,800
- Standard Car: ¥30,500 (1.0L to 1.5L)
- Automobile Tonnage Tax
- This is paid for two years at a time during the vehicle inspection, so we will calculate the per-year cost.
- Kei Car: ¥6,600 ÷ 2 years = ¥3,300
- Standard Car: ¥24,600 ÷ 2 years = ¥12,300 (for vehicles 1.5t or less)
2. Fuel Costs (for 1 year)
- Kei Car: 10,000 km ÷ 20.0 km/L × ¥170/L = ¥85,000
- Standard Car: 10,000 km ÷ 15.0 km/L × ¥170/L = ¥113,333
3. Insurance Premiums (for 1 year)
- Mandatory Liability Insurance: Calculated per year since it’s paid for two years at a time.
- Kei Car: ¥17,540 ÷ 2 years = ¥8,770
- Standard Car: ¥17,650 ÷ 2 years = ¥8,825
- Voluntary Insurance: This varies greatly by driver, so we will use an average estimate.
- Kei Car: Approx. ¥50,000
- Standard Car: Approx. ¥70,000
4. Other Costs
- Parking Fees:
- Kei and Standard Car: ¥10,000 × 12 months = ¥120,000
- Maintenance Costs: Oil changes, tires, battery, etc. Varies depending on the car and usage.
- Kei Car: Approx. ¥20,000
- Standard Car: Approx. ¥30,000
- Vehicle Inspection (Shaken) Reserve:
- The inspection occurs every two years. Here, we calculate the annual amount to save.
- Kei Car: ¥80,000 ÷ 2 years = ¥40,000
- Standard Car: ¥120,000 ÷ 2 years = ¥60,000
Annual Maintenance Cost Comparison (Total)
| Item | Kei Car | Standard Car | Difference |
| Automobile Tax | ¥10,800 | ¥30,500 | +¥19,700 |
| Automobile Tonnage Tax | ¥3,300 | ¥12,300 | +¥9,000 |
| Fuel Costs | ¥85,000 | ¥113,333 | +¥28,333 |
| Mandatory Insurance | ¥8,770 | ¥8,825 | +¥55 |
| Voluntary Insurance | ¥50,000 | ¥70,000 | +¥20,000 |
| Parking Fees | ¥120,000 | ¥120,000 | ¥0 |
| Maintenance Costs | ¥20,000 | ¥30,000 | +¥10,000 |
| Inspection Reserve | ¥40,000 | ¥60,000 | +¥20,000 |
| Total | ¥337,870 | ¥444,958 | +¥107,088 |
*This simulation is an estimate, and actual costs can vary depending on the car model, year, insurance class, gas price, and location.
Analysis of the Simulation Results
This simulation shows that the annual maintenance cost difference can be over ¥100,000. The main contributing factors to this significant difference are taxes, fuel costs, and voluntary insurance premiums.
These results confirm that a kei car’s biggest advantage is its cost-effectiveness. On the other hand, standard cars offer performance and safety benefits that kei cars lack. The choice between the two should ultimately be based on an individual’s lifestyle and priorities.
