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Comment by junto | Hacker News Reader

Many people who have bought diesels have made the decision based on the wrong criteria. They bought it because the fuel is cheaper and you get more miles to the gallon.

However people that only drive short distances daily (less than 15 minute trips. I.e. the school run), are damaging their diesel engines because the DPF (diesel particulate filter) needs at least 15 minutes to get to a temperature that can burn off the particulates.

People who don't regularly drive long distances in their diesels are therefore driving on false economy. The repair bills will end up outstripping the fuel savings. Also, as the article points out, cheap diesel is artificially cheap due to government incentives, which could (and probably will) be taken away at any time. People driving diesels in Europe are sitting on a financial time bomb.

http://www.thisismoney.co.uk/money/cars/article-2332107/Petr...

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In the Netherlands, government is actually incentivising people who drive a lot to buy diesel cars, but not those who drive only a little, and that is going on for quite a while already. Here is how it's done:

- Diesel fuel is considerably cheaper at the pump [0], plus diesel cars have better per-liter mileage. Thus per-mile expense for a diesel car is roughly 1/2 of that for a benzine car.

- Diesel car is roughly twice as expensive in yearly road tax (EUR 1580 / year for a 1500kg diesel car vs. EUR 808 / year for a 1500kg bezine car in Amsterdam) [1], plus a diesel car would typically be slightly heavier. Thus per-year expense is much higher for diesel.

Two observations above combine in a well-known locally rule of thumb - if you drive >20000km/year, buy a diesel; otherwise you're better off with a benzine car. This matches perfectly with the inherent technical requirement for a diesel car to be driven mostly in long trips to be efficient or relatively clean.

[0] http://www.anwb.nl/vakantie/reisvoorbereiding/brandstofprijz...

[1] http://www.belastingdienst.nl/rekenhulpen/motorrijtuigenbela...

The criteria aren't wrong: I want to save money on my car.

Diesel fuel is cheaper, by a lot. Diesel cars drive further than a petrol car (I get about 3.7l/100km). A diesel car produces less CO2, which makes it cheaper to lease (14% instead of 20%-25% for added tax).

If the government taxes the diesel car equally to a petrol car, then people will pick the cheapest.

Just get a cheap decent EV out there with similar properties of a fuel car, and people will pick that. And cheap is in the range of 20000-25000eu, not 60000eu like a Tesla.

Fuel is already taxed heavily here (just compare Europe fuel prices to US fuel prices).

And I don't know what a DPF is, how it works, or that my car has it. I shouldn't have to care about all the hundreds of components in my car. I have enought things to worry about already.

If the startup time is 15 minutes for that filter and that is too long, maybe there should be some force applied to reduce this startup time to say 5 minutes.

I didn't know what a DPF was, nor what an injector was. This January, a 4000+ euros repair bill educated me. This is a seven years old car and taking this bill and the higher car price in consideration, I would have been better buying a regular fuel car.

The particulate filtering technology for Diesel engines has been rushed to market. As well as DPF filters, EGR valves are another thing that get clogged with soot and fail if you do too many short trips. The diesel engines Vauxhall/Opel use are particularly susceptible to it. I had one fail in a 5 year old car, bought the part myself for £200 and my father in law helped me change it but that would have been a £500 garage bill in itself.

> Just get a cheap decent EV out there with similar properties of a fuel car, and people will pick that. And cheap is in the range of 20000-25000eu, not 60000eu like a Tesla.

Absolutely. I was quite disappointed with the $130k price tag on the new Tesla X. Brilliant car, but way too expensive.

The way you build cheap cars is to make expensive cars first.

The $130K Model X is the signature version. There are 1000 of them, and you had to pay $40K to claim a spot. They are fully loaded with every option. The lower trim packages will be available after those first 1000 are shipped.

The decision was made on right criteria. Usually, it is economy.

Diesel cars are more expensive than petrol cars. That means, you must make math, how much are you going to drive, in order to break even on the savings on diesel.

Usually, the break even point is about 20 000 km/year. You aren't going to make 20k km every year by doing school runs.

About the DPF filter burning: it does not burn all the time. Yes, it needs warm engine, but it needs it once for every few hundred kilometers (in my car, cca every 750 km). That is doable, even when living in the city. Combine that with the break even point mentioned above - it means, you are going to have some longer trip every week or two anyway, so it will burn out the DPF.

There are many other, more probable ways to damage your car by neglect or ignorance, resulting in expensive repairs, not only DPF ;).

"cheap diesel is artificially cheap due to government incentives, which could (and probably will) be taken away at any time."

The french govnerment has already announced it will remove the tax advantages on diesel by 2020, thanks to the Volkswagen scandal.

On the other hand, many newer diesels have cam chains instead of belts, which will just mean the big service at 100k miles (say) is a DPF service instead of a cam belt service. Costs are comparable (This is assuming the cam chain is trouble free and lasts forever, which isn't entirely true of course).

Even if the DPF is abused by short trips, there isn't even a scheduled inspection until over 100k miles, so if there are no noticable issues with it, it might just do a worse job for the environment but not incur higher ownership costs.

Over half of new cars here (Sweden) are leased by companies, and bought with very strict CO2 emissions guidelines, but no other guidelines. That means you either have to buy a hybrid or a diesel, there is basically no way you can get under 120g/km otherwise. Since there is of course also a price treshold, the hybrids are usually out of the question and the end result is that most new cars will be diesels.

How cute and naive, when DPF fails you simply CUT IT OUT (or hollow it out), problem solved.

How will the car pass inspection after that?

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