They cut down on emissions which means lower road tax but thats about it really. They are only really suitable if you do a lot of driving and regularly go on motorways.
Renault and the Diesel/Petrol decision
- Thread starter AndrewSchofield
- Start date
They cut down on emissions which means lower road tax but thats about it really. They are only really suitable if you do a lot of driving and regularly go on motorways.
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Renault own a controlling share in Nissan, so over the last 5 years or so, there has been a gradual rationalising of models between the two. Depending on age, you migh find that the Nissan will have a Renault engine anyway. They certainly share diesels these days.
If anything, I'd expect a diesel to give a bigger improvement in fuel economy compared to the petrol in town than on a mpotorway. Diesels do really well at part-throttle motoring, so any sort of driving where you're at small throttle openings will be much better in the diesel. Obviously, if you drive on the motorway with your foot almost to the boards, the difference in fuel consumption might not be quite as good as expected.
The DPFs get rid of the black, sooty smoke that diesels make when you boot them. I don't think they help with tax in any way - just the environment. They do, however, have a reputation (and not just on Renaults) for being troublesome. I don't think the technology is quite mature yet, and would think twice about buying an early DPF car.
With ANY second hand diesel, beware of one that a hard-up owner has tried to run on "chip fat" - the modern "common rail" diesels can't handle it and a new injection pump costs thousands.
Renault generally have a poor reputation for reliability with members of the trade that I've spoken to - but are improving. We hired a Grand Scenic on holdiay this year and I was very impressed. Overall, however, I rate the VAG diesels as about the best around at present (VW, Skoda, Seat).
If anything, I'd expect a diesel to give a bigger improvement in fuel economy compared to the petrol in town than on a mpotorway. Diesels do really well at part-throttle motoring, so any sort of driving where you're at small throttle openings will be much better in the diesel. Obviously, if you drive on the motorway with your foot almost to the boards, the difference in fuel consumption might not be quite as good as expected.
The DPFs get rid of the black, sooty smoke that diesels make when you boot them. I don't think they help with tax in any way - just the environment. They do, however, have a reputation (and not just on Renaults) for being troublesome. I don't think the technology is quite mature yet, and would think twice about buying an early DPF car.
With ANY second hand diesel, beware of one that a hard-up owner has tried to run on "chip fat" - the modern "common rail" diesels can't handle it and a new injection pump costs thousands.
Renault generally have a poor reputation for reliability with members of the trade that I've spoken to - but are improving. We hired a Grand Scenic on holdiay this year and I was very impressed. Overall, however, I rate the VAG diesels as about the best around at present (VW, Skoda, Seat).
When you consider how far diesels have developed in just a few years, its amazing how good they are......personally I like the PD diesel in VAG products but they can be a little smoky at times.
Thats a very valid point about the chip oil - maybe ok in the old idi engines but has absolutely no place in modern diesels.
I had a Citroen C3 Picasso hired in Spain earlier this year - what a superbly accomplished vehicle it was, too.
John
Thats a very valid point about the chip oil - maybe ok in the old idi engines but has absolutely no place in modern diesels.
I had a Citroen C3 Picasso hired in Spain earlier this year - what a superbly accomplished vehicle it was, too.
John
Yes, the arguments for buying a petrol car get weaker by the year as the diesel evolves. I think the Peugeot / Citroen / Ford diesels are probably the most refined that are currently available, but I like the VW ones a bit better. They're harsher, smoke a bit more, and seem to have less torque just above tickover (very easy to stall) but they rev-out more nicely and seem to be a bit better on fuel size-for-size than the French offerings.
I imagine the recent transition to Euro 5 emissions levels will mean they all have particulate filters and smoky diesels will be a thing of the past, it's just a question of geting the bugs out of the particle filter susyem.
It's a hard thing for a convicted petrolhead such as myself to have to admit, but my new(ish) company Peugeot 1.6 diesel is now more refined than my own (22 year old) petrol V6!
I imagine the recent transition to Euro 5 emissions levels will mean they all have particulate filters and smoky diesels will be a thing of the past, it's just a question of geting the bugs out of the particle filter susyem.
It's a hard thing for a convicted petrolhead such as myself to have to admit, but my new(ish) company Peugeot 1.6 diesel is now more refined than my own (22 year old) petrol V6!
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Avocet - its not so much "in town" driving, as lots of short journeys where the engine never gets chance to warm up. Her journey's will range from 30mph to 50/60mph in approximately equal measure and there wont be much sitting in traffic or at lights, but if she makes 20 journeys a week, probably 18 of them will be less than 4 or 5miles. Are diesels still more economical on fuel than petrols before they've had chance to warm up?
I agree with Peter, yes they would definitely be more economical under those conditions. HOWEVER, if you are considering buying a new car, I would urge you NOT to go for a diesel just yet. All the manufacturers are now being forced to bring out their new "Euro 5" models (The European Commission has just raised the bar again for its type approval emissions requirements) and that means all new diesels being fitted with particulate filters. These stop the black smoke on hard acceleration that you often see on diesels.
Unfortunately, I'm hearing reports of problems with them - ESPECIALLY under the driving conditions that you describe! They need a good 40-50 mile motorway thrash at least once a month, or some of them are experiencing problems with the filters getting clogged. Personally, I would steer well clear of any diesel with a particulate filter for a few years yet, while they get the technology sorted out. Remember also, that some diesels were fitted with them in advance of this Euro 5 deadline, so it would pay to ask the dealer whether it has one or not!
Unfortunately, I'm hearing reports of problems with them - ESPECIALLY under the driving conditions that you describe! They need a good 40-50 mile motorway thrash at least once a month, or some of them are experiencing problems with the filters getting clogged. Personally, I would steer well clear of any diesel with a particulate filter for a few years yet, while they get the technology sorted out. Remember also, that some diesels were fitted with them in advance of this Euro 5 deadline, so it would pay to ask the dealer whether it has one or not!
The only proven good common rail engines are the Peugoet/Citroen 8 valve 2.0 litre. They have no particulate filter and are very reliable. You will see 406s for sale with over 300,000 miles on them, I have a 200,000 miler which doesn't look as though the engine has been touched and they will do 60+ mpg driven carefully. They are only available up until about 04 after that they start to become problematic.
Peter
Peter
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