Diesel cars under fire in the UK press

[Stuart]

This article only applies if you choose to buy a new diesel car. But I found all the comments were good reading

http://www.dailymail.co.uk/news/article ... s-car.html

[Rhynri]

I see a post from one of our own in there, the cheeky bastard!

[Tamber]

Hmm, looking at the nice little graphic they've got there, and one thing stands out to me: They don't seem to be comparing things entirely fairly; careful choice of models to get the best results for their survey, perhaps? Surely it's common sense that a vehicle with a larger engine is going to cost a little more to run, unless you're careful? It also amuses me somewhat how much less 'scary' it gets if you look at how long it takes to 'break even' with urban driving.

If I were a somewhat more tinfoil-hatted type, I'd suspect someone's worrying about the apparently growing market for biofuels; of which there is more choice for diesel vehicles. But going down that route of thought leads to strange, worrying places.

I still think that diesels are the way to go, though; as much as you can try to squeeze more eco-friendliness out of petroleum distilliates, diesel engines still give you more choice for alternate fuels. (At least, with my understanding of it. With petrols, you have petroleum distilliates, or alcohols; with diesels, you have petroleum distillates, alcohols, various vegetable oils, etc.)

...Yes, I have my tinfoil ready; but it's for my sandwiches. :p

[Rhynri]

I would also like to note that diesels almost always exceed their posted MPG figures whereas petrol vehicles rarely make them. You have longevity, you have the fact you can make the fuel yourself, longer oil change intervals, etc. Not to mention the MOUNTAINS of low range torque, which makes those little bitty cars feel faster than they are. Also, that Peugot in the article is sexy, I want one.

[oldbmw]

Pity they neglected to include the Fiat panda.

Diesel = 76mpg
petrol 51 mpg

One of the real advantages is the range on a tank full of fuel.

[Rhynri]

That's true in most of those cars, I would imagine. they also don't mention how much zippier the diesels feel than the petrol engines, which is a big part of the driving experience, nor do they mention the fact that many diesel cars (including the jetta) are tow rated for up to 3k pounds.

[Dan J]

This article misses the crucial point for me regarding the diesel/petrol debate which weighs significantly in favour of petrol today - overall cost of ownership.

Euro 5 and (due 2014) Euro 6 diesel engines are massively complicated beasts built to comply with emission regulations. Engines are invariably fitted with particulate filters and run on very high pressure common rail principles with specialist injection equipment. In the quest for ever greater fuel economy and lower emissions the simple and infinitely reliable diesel engines of old have long gone. People are obsessed with fuel economy, CO2 figures and their annual licence costs but don't look at the bigger picture. When something goes wrong with one of the plethora of sensors on new diesels, the complex injection systems and computers controlling it or the emission reduction system you are looking at a very significant bill to sort this out. In many cases this makes a 7+ year old car irrepairable if at least from an economical perspective. If you have a company car or change cars regularly you're only affected by the points raised in the Which?/Daily Mail article as your car is under warranty the whole time and you're probably paying less benefit in kind. Pity the poor sods who buy "nearly new" or cars that are a few years old off a dealer (franchise or not) forecourt that have very limited warranties or even decent ones for only 12 months. The fuel economy and what you saved there is going to be quickly forgotten when you're getting your second £1,500 bill to replace the particulate filter in 4 years. You only need to spend several moments looking through any modern day car forum to see all the problems people are having with recent diesels and that will only get worse with Euro 6.

The manufacturers love this right now (I used to work for one and my wife still does). It is pushing cars down the route of consumable goods like smartphones and computers where several years down the line you don't repair and keep going you merely throw away and buy another. The downside is that it is costing more and more to produce diesel cars which will always be passed back to the consumer hence the original Which article.

Back to my original point, petrol technology hasn't massively changed in the last few years and neither have the (already very low) emissions limits. Modern petrol cars are fitted with catalytic convertors and have pretty careful fuel injection keeping them within limits. There's still much to go wrong but it things are much simpler and certainly cheaper when they do. I'd always take a diesel car as a company car (I love the driveability of the big-engined autos) but if it was my own money? Petrol every time.

And I guarantee you my comments on reliability and cost of ownership will start filtering to used car values once people have realised modern diesel cars are not the most reliable of prospects...

[Rhynri]

The flip side of that coin is the longer warranty intervals on powertrains that are popping up. My car is covered to 100k with no time limit on the whole beastie, and farther on the power train. While I'll likely own it for longer, I also have a VAG-COM, which is capable of telling you down to the relay what is wrong with the vehicle, so I can do a lot of the repair work myself. And until that 100k mark, I'm not even paying for oil changes. It's an interesting thought though, and I am not sure I could give up all the torque for a gasoline engine on a daily basis.

[Stuart]

Well put there Dan. As someone who's kept a 1.4 Peugeot going since 2000 I can see the advantages of staying away from the more complex and costly cars. That said, I'm still a diesel fan for the economy and have been considering going the Toyota route after the Pug dies because they are supposed to be pretty reliable. But for the moment the Pug is still passing it's emissions tests so I won't be splashing the cash just yet

[Rhynri]

It just occured to me that perhaps an electric vehicle is the ultimate solution. Aside from battery replacement (which research in progress right now should solve) there are almost no moving parts, so it is perhaps the best of all worlds (torque, reliability, efficiency).

[Crazymanneil]

Nicely written post Dan. Captures the scene pretty well at the moment IMHO.

n

[BertTrack]

In response to Dan and the Particulate filter business.

I wish the manufacturers would tell their customers or at least show them how and when the filter is regenerating. I'm lucky enough to have a DashDyno computer extra in my car so i notice from watching the numbers that the engine is regenerating. I can then assist it to keep on doing that until it's all done.

Trick with the particulate filters is not to hammer the engine in low revs (unlike what the manufacturer would like you to believe) especially when the engine is cold. And i mean cold as in under 20 minutes runtime.

My mom has a 1.4tdi Ibiza ecomotive and pulls a caravan. Despite my advice she continued to drive to south of France following the board computers advice for gear selection. She didn't make it far into France. Then had some garage try a different turbo pressure controller. (Standard solution to all problems they think) And then i told them on the phone to just drive it around for 30 mins over 3000rpm. (which causes the egr valve to remain shut) Not hammering it but just riding normal speeds. After that it was all done.

Since then she keeps the engine over 2200 when pulling the caravan and never had a problem anymore. And 5th gear is no longer an option then.

I have the 1.2 tdi Skoda Greenline and never have problems with it. I have noticed that aborting the regeneration cycle will cause the engine to restart it very soon during the next ride.

Diesels have never been build to be sporadic use engines. But it's easy to forget.

[Rhynri]

Yeah, I hate the short trips I'm having to take in mine on base. Every week I make sure to get it out, get it warm, then drop the hammer a bit. It seems to love it, especially breaking loose those grippy tires in the first three gears. The thing pulls like God's own hand is pushing you.