I've just bought a VW Caddy with a 1.6 TDI diesel engine, having not had a diesel engine before I'm wondering how they differ from petrol.
One thing I've noticed is that if I'm driving slowly for example through a car park and I put it into second gear, even before I've applied any "gas" it'll be pulling quite strongly whereas a petrol car would be coming close to stalling in my experience.
Can anyone comment on what kind of revs a diesel engine like this will be producing maximum power - I've found it'll cruise happily in 5th at 60mph on just less than 2000 RPM
The other thing you'll find different is engine braking, It's much more effective than on a petrol car. I drove various diesel cars for about 30 years, so have forgotten how a petrol car went. I'm now using an EV - which I've had for 2 years.
Yes, when I first got a diesel car (Peugeot 306 with 1.9 non-HDI engine) in 1995, it was a revelation that it would pull on the level in 1st or
2nd with no throttle input and the engine at idling. Makes it very easy to crawl along in a queue of traffic: foot off throttle, lift clutch until car is going at speed of car in front, drop the clutch and let the car roll.
Not sure what the max-torque and max-power engine speeds are for a diesel, but they will be a lot less than for a petrol. At a guess, maybe
3000 rpm.
When I took my second diesel car (Pug 306 with 2.0 HDi engine) into the garage, I was loaned a 1.8 petrol. Its 0-60 and indeed 0-20 times were superb, and took some getting used to, but on the motorway the engine was screaming away at about 4000 rpm in top gear (5th? 6th?) and the car had bugger-all 50-70 acceleration in any gear when I came to overtake a lorry that I'd got stuck behind. I was glad to get my own car back:
50-70 acceleration and quieter engine at 70 are far more important to me than 0-60 time.
My present car, Pug 308 with 1.6 HDi, is now 15 years old and has done
190,000 miles. And its acceleration and low-speed torque are still damn good, and its fuel economy still averages about 50-55 mpg (average over
650 miles / 60 litre tankful) as it did when the car was new.
The low-speed torque of a diesel make it a doddle to do a hill start on a steep hill. I was going up a 1:3 / 33% hill near me and the car in front ground to a halt. When he eventually got going, after a lot of engine racing and rolling back towards me several times, I set off. In first, the car set off with the engine going not much above idling, so I didn't have to slip the clutch as much as I would in a petrol where you might need 1500-2000 rpm to avoid stalling when letting the clutch up on a 33% hill.
The only diesel that defeated me was a Mark IV VW Golf which had a very odd engine whose engine-management system seemed to be programmed to cut the fuel completely (so the car stalled) if you let the clutch in too far or didn't have high enough revs, where most cars would just labour a bit, giving you chance to dip the clutch or apply more engine revs. I was test-driving it with a view to buying it, and the salesman said that every one did it until they got used to it. Not a well-programmed ECU if it sulked and threw its toys out of the pram because I got things slightly wrong, rather than failing gracefully. The later model, Mark V, had a much nicer engine that behaved like a proper diesel.
In message snipped-for-privacy@googlegroups.com, Murmansk snipped-for-privacy@gmail.com writes
Have a dip through the VW forums. I use voltswagen Forum.co.uk but there is a choice.
The 1.6 Peugeot diesel is an excellent engine now hampered by CO2 and NOX emission boltons:-(
We have one fitted in a 2009 Fiesta and one in a 2012 VW Passat Estate. Ample torque for such a big vehicle.
The early versions have issues with MOT smoke failures due to soot collecting in the DPF. (diesel particulate filter) The cure is to use low Sulphur fuel (expensive) and do a long motorway run prior to the test. Ours have both had recent necessary trips to the Suffolk coast:-)
Modern dual mass flywheels don’t like slogging at very low revs. The do a great job of damping vibrations but can be damaged if the revs drop too much, hence some manufacturers fit a low rev engine cut out to protect the flywheel.
Driving through town, I missed a gear change and instead of going into
2nd, went into 4th. There was a lot of clattering for a short time. After that, there was a lot of vibration at certain revs. It took a lot of thought at the local garage before they diagnosed a broken dual mass flywheel.
I wonder if that's why my 2010 1.6 fiesta cuts out if I keep it in too high a gear. Unlike Tim Lamb's mine had no dpf from new and that's why I am keeping it. It still manages 71mpg.
The main difference is they love low rpm. Lower rpm for the same power out is more fuel efficient. Treat over 2k rpm as unnecessarily fast if you want economy. Some can run on free alternative fuels, but do your reading to avoid problems.
Some garages even replace with a nom-dual mass clutch and flywheel, but the dual mass jobbie is part of the overall emissions calculations for that model.
I had to have my DPF replaced some time ago (my car has done 190,000 miles now) and the bill was nasty. They had to replace the catalytic converter at the same time because a thread stripped on a connection between the two, though the garage consoled me with the thought that the cat probably didn't have much more life in it so would have needed replacing fairly soon. The total bill was £1000. That's by far the biggest single bill I've had to pay for the car. It's still on its original clutch and as far as I know the dual-mass flywheel is OK, though I'm not sure what the symptoms of a failing/failed DMF are.
I didn't know that DMFs don't like very low engine revs under heavy load - rather makes them a silly choice for a diesel-engined car ;-)
71 mpg is pretty damn good. My car, a Peugeot 308 1.6 HDi, has averaged about 55 mpg over the 180,000 miles that I've had the car. That's with very little around-town driving, mostly motorways, A roads and country lanes, so not much constant 30 mph driving and stop/start.
The car still goes like a bomb - plenty of acceleration out of bends and pulling up hills when I need it. The only fault it has now is rather lumpy running at low speeds - eg approach a hazard with my foot off the accelerator, then apply a bit of power to maintain constant speed to to accelerate very slightly - this sometimes causes a lag of about a second before the engine responds. It improved after the garage replaced the air filter (due to a misunderstanding, this had not been replaced for several services) but seems to have come back again.
I'm keeping the car "forever" because it is worth a lot more to me as a working car than for its negligible second-hand value. When I come to replace it, I imagine I'll be looking for the newest second-hand diesel that I can buy once sales of new diesel- and petrol-mechanical cars are banned and you can only buy petrol-electric hybrids and pure-electric cars. I'm scared stiff with a pure-electric than I might find myself stranded somewhere or have to break a long journey for longer than a normal pee-and-coffee break while the car is recharged. There is also the interesting social problem of how you pay to use a friend's electricity if you go to stay with them: it's not just a case of stop at any reasonably-priced garage somewhere on the journey, fill up and be on my way again in five minutes.
I pour a lot of maintenance money into mine, to keep it reliable and smart, but it's still way less than the HP on a new one would be, or the contract hire, and besides, the newer ones aren't so fast :-)
There is a sweet spot with old luxury cars where the resale value is practically nothing even on a low mileage example, but you still have
100k+ in the engine and gearbox.
And you get to drive a £40k+ car for less than £4k...
Both our diesel cars are used mostly for short, local trips. Bad news for exhaust filter blockage. When new, 12 or so years back, the Fiesta engine management would trigger a *burn* cycle where the coolant fan ran at full speed and excess fuel was put through the injectors. Performance would be way down until the next engine switch off so I learned to do this on the move:-) Not noticed this happen for some years and followed up your annual engine oil/filter change with the MOT mechanic. He agreed and included engine air intake filter followed by a generous high speed run pre-test.
My intent has been to replace the Fiesta with an electric *shopping trolley* but new prices and user preferences make this a struggle:-)
I keep thinking about it, but frankly they are so dull ...and expensive...and depreciate even faster than a Jaguar.,..and they still need insuring and charging and and and they wont do the really long trips I do once or twice a year..
And are currently no cheaper than diesel even WITH fuel tax and VAT on top
Even though I can buy a pug/corsa EV new for £20k and by adding another 4kWp of PV panels I could run it for 9 months of the year without buying electricity it makes no sense until one of my other cars bites the dust. Also I do a fraction of the mileage I did before I retired. As it is I only use the diesel for trips exceeding 50 miles, it costs next to nothing in devaluation now, I service it every 8k miles and tax goes from free to a small amount in April. At 70mpg it cost only
10p/mile to run even at current prices and I like it.
I still don't understand how your 2009 fiesta has a dpf and my 2010 one doesn't. Same 1.6 pug engine.
Same basic engine but my car is an "eco" model, a bit lower power and low ground clearance. I seldom use motorways ( reminds me of commuting to work too much) and am generally not in a hurry but don't exceed an indicated 70mph or 60mph on single carriage ways. I switch off at traffic lights manually and try and anticipate the conditions ahead to avoid braking, as my mate says " driving uses fuel, braking wastes it".
I got slightly better economy from my work 206 van with the 1.4 hdi and that retired with me at 305k miles as no one else at the firm would take it on.
Exactly but I am completely sanguine about an all electric EV, I have been tempted to treat myself to a Tesla Y extended range dual motor for £60k, it accelerates faster than my bike and out paces it by 15mph but my grand-kids may enjoy the money more.
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