Diesel cars are popular with many people because of their fuel efficiency and torque. However, there are also many people who say, ” Don’t buy a diesel car .” In this article, we will explain in detail the disadvantages and points to be aware of before purchasing a diesel car.
Diesel cars have an image of being fuel-efficient and powerful, but I also hear people say, “Don’t get one.” What exactly is true?
“I’ve heard that diesel cars are fuel-efficient and powerful, but is that really true?”
“Some people say you should avoid diesel cars, but are there any drawbacks?”
For those of you with questions like these.
In this article, we will explain in detail not only the advantages of diesel cars, but also the disadvantages and points to be aware of before purchasing . If you are considering purchasing a diesel car, please use this article as a reference to make a decision you will not regret.
What is a diesel car? The current state of clean diesel
Diesel vehicles are automobiles that run on diesel fuel . They use a different combustion method than gasoline vehicles, and achieve powerful driving through spontaneous ignition due to a high compression ratio.
The evolution of clean diesel technology
The “clean diesel” cars available on the market today are a significant improvement over conventional diesel cars:
- Significant reduction in exhaust gas emissions : DPF (diesel particulate filter) and urea SCR system significantly reduce PM (soot) and NOx (nitrogen oxides)
- Improved quietness : The common rail high-pressure fuel injection system significantly reduces the conventional “rattle noise.”
- Improved fuel efficiency : Achieves 20-30% improvement in fuel efficiency compared to gasoline vehicles
- Environmental performance : CO2 emissions are approximately 20% lower than gasoline vehicles
Why are people told to avoid diesel cars?
Diesel cars have some drawbacks and points to note:
- High vehicle prices: Diesel vehicles are more expensive than gasoline vehicles and have higher initial costs.
- High fuel prices: The price difference between gasoline and diesel fluctuates, but diesel is generally more expensive.
- High maintenance costs: Maintenance costs tend to be high because diesel vehicles require replacement of parts specific to the vehicle, such as engine oil and filters.
- Loud noise and vibration: Compared to gasoline vehicles, the engine noise is louder and vibrations are more noticeable.
- Strict exhaust gas regulations: Environmental regulations require vehicles to be equipped with exhaust gas purification devices, and if they break down, repair costs can be expensive.
- Poor starting in cold temperatures: The engine may be difficult to start, especially in cold climates.
- Pay attention to the quality of the fuel: Poor quality diesel can have a negative effect on your engine.
- Used car prices are more likely to fall: When selling in the future, used car prices tend to fall more easily than gasoline-powered cars.
Why people say “avoid diesel cars”
Diesel cars are characterized by better fuel efficiency and stronger torque than gasoline cars. Therefore, they are suitable for long-distance driving, and diesel cars are more economical for people who drive a lot on highways.
However, diesel vehicles have some disadvantages, such as higher vehicle prices and louder noise than gasoline vehicles. In addition, there are concerns that the use of diesel vehicles may be restricted in the future due to the recent strengthening of environmental regulations.
High purchase costs
Diesel engines are more complex and expensive to manufacture than gasoline engines, so diesel cars are generally priced higher than gasoline cars. Because the initial investment is large, it takes a long period of use to recoup the difference in fuel economy.
Maintenance costs
Diesel vehicles have complex engine structures, so regular maintenance is important. In particular, cleaning and replacing the diesel particulate filter (DPF) and changing the engine oil are necessary, and these maintenance costs are often higher than for gasoline vehicles.
AdBlue is required
Some diesel engines use AdBlue to purify their exhaust. AdBlue is a high-quality urea solution used as a reducing agent in the urea SCR system, which is used to reduce air pollution from diesel engines. While this varies depending on the vehicle model and driving conditions, it will reduce by approximately 1 liter per 1,000 km.
The price is about 2,000 yen for 10L.
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— トトロ🍃 (@TOTORO_JZX100) July 6, 2024
Vibration and noise
Diesel engines tend to vibrate and make more noise than gasoline engines. Some people complain about the rattle they make when idling or accelerating. If you value quietness, diesel cars may not be for you.
Engine life and durability
Diesel engines are said to be more durable and last longer than gasoline engines, but neglecting maintenance increases the risk of breakdowns, so care is needed.
Diesel cars in the used car market
Compared to the past, diesel cars are becoming less popular, and as a result, their resale value in the used car market may be lower than that of gasoline cars.
Strengthening environmental regulations
As environmental regulations become stricter worldwide, emissions standards for diesel vehicles are also becoming stricter. This will further increase the development and manufacturing costs of diesel vehicles, which may affect new car prices and maintenance costs. In addition, regulations on diesel vehicles in urban areas may be tightened in the future, which may limit their range of use.
Six advantages of diesel cars
1. Extremely low fuel costs
Fuel efficiency : 20-30% improvement compared to gasoline vehicles Fuel price : Diesel is about 20 yen/L cheaper than regular gasoline
Comparison example with Mazda CX-5
- Diesel car: 17.4km/L, diesel 154 yen/L → about 89,000 yen for 10,000 km
- Gasoline vehicle: 14.6km/L, gasoline 175 yen/L → about 120,000 yen for 10,000km
- The difference is approximately 30,000 yen per year
2. Powerful torque from low revolutions
- Starting acceleration : Powerful acceleration with just a light press of the accelerator
- Climbing performance : Ample power to climb uphill
- Expressway : Smooth acceleration for merging and overtaking
- Compatible with SUVs and large vehicles : Accelerates easily even with heavy vehicles
3. Excellent economic efficiency
The more mileage you drive per year, the better
- Over 15,000 km: Diesel is the clear winner
- Over 20,000 km: The difference in vehicle price can be recovered in 3 to 4 years
4. High structural durability
- Robust design that can withstand high compression ratios
- With proper maintenance, it can run 200,000 to 300,000 km.
- Use in the low rotation range reduces engine load
5. Tax benefits (conditions apply)
Clean diesel vehicles are eligible for the following incentives:
- Eco-car tax reduction (automobile weight tax)
- Reduction of environmental performance tax
- Greening Special Measures (Automobile Tax)
6. Environmental performance (CO2 reduction)
- CO2 emissions are approximately 20% lower than gasoline vehicles
- Meets the latest emission regulations
- Contributing to carbon neutrality
Important points to note about diesel vehicles
When purchasing a diesel vehicle, you should also pay attention to the following points:
The importance of mileage
Diesel cars are suitable for long distance driving, and short distance driving or urban use are more likely to cause engine deterioration and clogged DPFs. If you are a weekend driver or have a short commute, a petrol or hybrid car may be a better choice.
Diesel soot problem
It seems that some cars have diesel soot problems.
I switched from a CX-5, and personally, I don’t mind it! I don’t think diesel has that problem these days either!
Mazda’s diesel has engine soot issues. 🥹 I wouldn’t recommend it for people who only commute short distances, drive around town, or rarely drive long distances. 😅— Maitan (@maitan_dwnq) July 3, 2024
Fuel quality
Diesel engines require high-quality fuel. Using low-quality diesel fuel can cause carbon buildup inside the engine, reducing performance and increasing repair costs. It’s important to buy fuel from a reputable gas station.
Winter use
In cold climates, there is a risk of diesel fuel freezing. This can reduce engine starting performance, especially in the middle of winter, so preventative measures are necessary. This problem can be mitigated by using diesel fuel specifically designed for cold climates and an engine block heater.
Diesel vehicle maintenance and repair costs
Maintenance precautions
Diesel vehicles require more maintenance than gasoline vehicles, such as changing engine oil and filters, and failure of the exhaust gas purification system can lead to expensive repair costs.
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— 南行@旅人投資家（FIRE生活3年目） (@mxa03032) June 29, 2024
Repair costs
Diesel vehicles tend to be more expensive to repair than gasoline vehicles because the parts themselves are more expensive.
Manufacturer Support
Maintenance support for diesel vehicles varies depending on the manufacturer, so be sure to check the dealer’s support system before purchasing.
Diesel vehicle fuel efficiency and fuel costs
fuel economy
A major advantage of diesel cars is that they offer better fuel economy than gasoline cars, and this difference is particularly noticeable when driving long distances.
diesel price
Diesel tends to be more expensive than gasoline. Also, be aware that some gas stations do not carry diesel.
How to maximize fuel economy?
You can maximize the fuel efficiency of your diesel vehicle by driving eco-friendly. Avoid sudden acceleration and braking, and choose the appropriate gear.
Diesel vs. Gasoline Car Comparison {#Diesel vs. Gasoline Car Comparison}
| Comparison items | Diesel vehicles | Gasoline vehicles |
|---|---|---|
| Vehicle price | Expensive (+200,000 to 500,000 yen) | cheap |
| fuel cost | Cheap (difference of about 30,000 yen per year) | expensive |
| Driving feel | Powerful torque | Smooth rotation feel |
| Quietness | Improved but still slightly inferior | Excellent |
| maintenance | It is time-consuming and costly | Relatively easy |
| durability | High (200,000-300,000 km) | Standard (150,000-200,000 km) |
| Environmental performance | Low CO2/NOx measures needed | High CO2/Low NOx |
Break-even point estimate
Break-even years by annual mileage
- 10,000 km/year: 7 to 8 years
- 15,000 km/year: 4 to 5 years
- 20,000 km/year: 3 to 4 years
- 30,000km/year: 2-3 years
Who is suitable for diesel cars and who should avoid them?
People who are suited to diesel cars
✅High annual mileage (over 15,000 km) ✅Do a lot of driving on highways and suburban roads ✅Prioritize power in an SUV or large vehicle ✅Carry a lot of luggage for outdoor activities and leisure ✅Like long-distance driving ✅Want to save on fuel costs ✅Plan to keep the car for a long time (over 5 years)
People who should avoid diesel cars
❌ Low annual mileage (less than 10,000 km) ❌ Mainly short-distance driving (a few kilometers each day) ❌ Quietness is the most important factor ❌ Want to keep initial costs down ❌ Don’t want to bother with maintenance ❌ Mainly use in cold climates ❌ Not knowledgeable about cars/not interested in maintenance
Diesel selection checklist
Points to check before purchasing
- Do you drive more than 15,000km per year?
- Do you run continuously for more than 20 minutes at least once a week?
- Do you understand DPF regeneration and AdBlue refilling?
- Can you afford the increased maintenance costs?
- Are there any repair shops that can handle diesel?
Why you shouldn’t buy a diesel car
Environmental regulations in urban areas
Some cities are imposing stricter regulations on diesel vehicles, which may limit their use in the future.
Taxes and car insurance
Diesel vehicles may be subject to higher automobile tax and automobile weight tax than gasoline vehicles.
In the past, diesel vehicles were taxed at a higher rate of about 15% than regular vehicles. However, the system changed significantly in October 2019, and new diesel vehicles registered after March 31, 2009 are now taxed at the same rate as regular vehicles, with no additional tax.
Motor vehicle tax rate table for newly registered private passenger cars
This is an automobile tax that applies to both regular cars and diesel cars, which are private passenger cars classified by engine displacement.
| Engine displacement | automobile tax |
|---|---|
| 660cc | 10,800 yen |
| 1,000cc or less | 25,000 yen |
| More than 1,000cc but less than 1,500cc | 30,500 yen |
| More than 1,500cc but less than 2,000cc | 36,000 yen |
| More than 2,000cc but less than 2,500cc | 43,500 yen |
| More than 2,500cc but less than 3,000cc | 50,000 yen |
| More than 3,000cc but less than 3,500cc | 57,000 yen |
| More than 3,500cc but less than 4,000cc | 65,500 yen |
| More than 4,000cc but less than 4,500cc | 75,500 yen |
| More than 4,500cc but less than 6,000cc | 87,000 yen |
| Over 6,000cc | 110,000 yen |
Automobile tax from October 2019
Reference: Ministry of Internal Affairs and Communications
Tax incentives for clean diesel vehicles
From January 2024, the fuel efficiency standards for vehicles eligible for tax incentives will be raised, and it appears that the number of eligible vehicles will be significantly reduced.
| 2030 fuel efficiency standards | tax rate |
|---|---|
| 120% achieved | duty free |
| 90% achieved | duty free |
| 80% achieved | 50% reduction |
| 70% achieved | 25% reduction |
Vehicle weight tax rate for green diesel vehicles (if acquired between January 1, 2024 and April 30, 2025)
- *The reduction is limited to vehicles that meet the 2020 fuel efficiency standards.
- *For private passenger cars that comply with 2018 exhaust gas regulations
- *Including hybrid vehicles
Reference: Ministry of Economy, Trade and Industry
clean diesel vehicles
Clean diesel vehicles are diesel vehicles that have reduced their environmental impact through exhaust gas purification technology, but they still have a higher environmental impact than gasoline vehicles.
Durability and driving performance of diesel vehicles
durability
Diesel engines are designed to be robust and withstand the stresses of high compression, so with proper maintenance they will last a long time.
Long-distance driving
Diesel cars are ideal for long-distance driving because of their strong torque and good fuel economy. You can enjoy stable driving on the highway and powerful acceleration.
Torque and acceleration
Diesel engines generate large torque from low revolution ranges, giving you a powerful acceleration feeling. You can experience smooth acceleration when starting off or overtaking.
Popular diesel cars
In the Japanese market, diesel vehicles, especially SUVs, such as the Toyota Land Cruiser Prado, 70/250/Hiace, Mazda CX-5, and Mitsubishi Delica D:5, are gaining popularity.
What are the benefits of choosing a diesel car?
In addition to the drawbacks, diesel vehicles also have the following advantages:
- Fuel efficient: Compared to gasoline vehicles, it has better fuel efficiency, helping you save on fuel costs.
- Strong torque: It delivers powerful torque even at low revolutions, providing excellent acceleration and traction.
- Suitable for long-distance driving: The fuel efficiency of diesel vehicles is put to good use when driving long distances on highways, etc.
- Stable fuel supply: In times of disaster, diesel may be more stably supplied than gasoline.
What to check before buying a diesel car
When considering buying a diesel car, here are some things to consider:
- Annual mileage: If your annual mileage is short, there is little benefit in fuel costs, and due to the high vehicle price and maintenance costs, a gasoline vehicle may be more cost-effective.
- Usage environment: When using in cold climates, be aware of poor starting performance at low temperatures. Also, in areas with strict exhaust gas regulations, it is necessary to select a vehicle that complies with the regulations.
- Budget: Consider not only the price of the vehicle but also maintenance and fuel costs, and choose a car model that you can comfortably purchase within your budget.
- Test drive: Take a test drive in a diesel vehicle to check the noise, vibration, driving feel, etc.
Comparison of diesel and gasoline vehicles
Diesel and gasoline cars each have their own advantages and disadvantages, so you need to consider which car to choose based on your needs and budget.
Advantages of diesel cars
- Good fuel economy
- Strong torque
- Suitable for long distance driving
Disadvantages of diesel cars
- High vehicle prices
- It’s noisy
- Sensitive to fuel quality
- Poor starting in cold climates
- Tighter environmental regulations may limit future use
Advantages of gasoline cars
- Low vehicle prices
- Low noise
- Not very sensitive to fuel quality
- Easy starting even in cold climates
- Less susceptible to strengthening environmental regulations
Disadvantages of gasoline cars
- Poor fuel economy
- Low torque
- Suitable for short distance running
The lifespan and future prospects of diesel vehicles
Physical life of the engine
General lifespan guideline
- Diesel vehicles: 200,000 to 300,000 km (15 to 20 years)
- Gasoline vehicles: 150,000-200,000 km (10-15 years)
Reasons for long life
- Robust structure that can withstand high compression ratios
- Use in the low rotation range reduces engine load
- Track record in commercial vehicles (over 500,000 km is not uncommon)
Lifespan trends by manufacturer
| Manufacturer | Lifespan trends | Features |
|---|---|---|
| Toyota | Over 20 years and over 300,000 km | The Land Cruiser Hilux is particularly sturdy |
| Nissan | 15-25 years/300,000km class | High reliability, especially for commercial vehicles |
| Isuzu | More than 500,000 km possible | Top class in trucks |
| Mazda | New technology promises the future | Evolving with Skyactiv-D |
| European cars | Over 200,000km possible | High precision, but caution is required regarding the electronic control system |
Future regulatory trends
Japanese policy
- 2035: Target for electrification of new car sales
- 2050: Carbon neutrality goal
Current situation
- No driving restrictions as of 2024
- Clean diesel will continue to be sold for the time being
- Strong demand in the used car market
FAQ
Q1. Which is more economical, a diesel car or a gasoline car?
A. It depends on the annual mileage:
- Over 15,000 km : Diesel cars are a good deal
- Less than 10,000 km : Gasoline cars are a good deal
- 10,000-15,000 km : Depends on how you use it
Q2. What happens if the DPF gets clogged?
A. The following symptoms may appear:
- Warning lights are on
- Decrease in engine power
- Deterioration in fuel economy
- In the worst case scenario, the engine will stop
Countermeasure : Periodically drive the vehicle continuously for 20 to 30 minutes or more to complete DPF regeneration.
Q3. What if I run out of AdBlue?
A.The engine will not be able to restart.
- If a low-level warning appears, replenish as soon as possible.
- Can be refilled at dealers and gas stations
- The cost is around several thousand yen to 10,000 yen per year.
Q4. What if I put gasoline in a diesel car?
A. Avoid at all costs:
- The engine is not running properly
- Produces white smoke and stops
- Expensive repair costs
What to do : Stop the engine as soon as you notice it and have the fuel drained.
Q5. How long can I drive a diesel car?
A. Current Regulatory Status:
- No driving restrictions as of 2024
- 2035 new vehicle electrification target
- Carbon neutrality goal by 2050
- Can continue to be used for the time being
summary
Diesel cars have both advantages and disadvantages.
Diesel cars have many advantages, but it’s also important to understand why people say, “Avoid diesel cars.” Before purchasing, you need to be fully aware of the disadvantages, such as high initial costs, maintenance costs, and stricter environmental regulations, and carefully consider whether a diesel car is suitable for your lifestyle and driving environment.
Diesel vehicles are economical vehicles that are suitable for long-distance driving. However, they also have disadvantages such as high vehicle prices and loud noise. Furthermore, there are concerns that the use of diesel vehicles may be restricted in the future due to the recent strengthening of environmental regulations.
When choosing a diesel car, you need to consider factors such as mileage, fuel quality, cold weather use, and environmental regulations. You should also compare diesel and gasoline cars to see which one is right for you.
When considering a purchase, be sure to refer to the precautions and points to check explained in this article and choose a model that suits your lifestyle and usage environment. For those who can make the most of the benefits of diesel cars, this should be an attractive option.
Who can recommend a diesel car?
- Drive more than 15,000 km per year
- Lots of long-distance driving
- Looking for a powerful ride
- I want to save on fuel costs
- I plan to drive the car for a long time
People who should avoid diesel cars
- Mainly short distance driving
- Quietness is paramount
- I hate the hassle of maintenance
- Want to reduce initial costs
Key points for success
- Understand your usage correctly
- Understanding DPF regeneration and AdBlue
- Establish a maintenance system
- Test drive to check noise and vibration
Modern clean diesel vehicles have evolved so much that they can be considered a completely different beast from conventional diesel vehicles. With proper use and maintenance , they can be excellent companions that offer fuel-efficient, powerful driving for a long time.
When considering a purchase, we recommend that you make a careful decision based on your lifestyle.
I hope this article helps you choose your car.
Diesel vehicle recommended products
5W-30 Hayabusa Engine Oil DL-1/CF-4 5W30 for Japanese Diesel Vehicles, 1 Can (20L)
- High-spec Japanese-made engine oil “Hayabusa ver.2.0”
- Ideal for Japanese passenger cars and Hiace vehicles
- For Japanese clean diesel passenger cars (oil for vehicles equipped with DPF/GPF)
- “Hayabusa” is a high-spec engine oil made in Japan that has been researched and developed to suit the characteristics of Japanese cars and ensure the vehicle achieves maximum performance in any driving environment!
- It provides excellent lubrication and sealing performance even at high speeds, providing the driver with the best driving experience!
- Not only does it contain less sulfated ash, which can cause DPF clogging, but it also uses a synthetic oil (VHVI, Group III) that is more powerful than regular mineral oil as its base oil, which reduces filter clogging due to oil evaporation.
- This high-performance DL-1 compliant oil also contains molybdenum to protect your engine!
