Does a diesel vehicle (car) still stack up?

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#1456484 24-Dec-2015 12:37

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Aaroona:
alasta: I have a Mazda3 SP22 Limited diesel which theoretically has the same operating costs as the SP25 Limited, the petrol equivalent. Comparing the two:

- The petrol engine has 7% more power.
- The diesel engine has 68% more torque.
- The diesel engine is slightly clattery with the throttle open at low speeds, but smooth as silk at highway speeds.
- The diesel engine is prone to the particulate filter clogging up if driven continuously for very long distances in slow stop/start conditions.

The diesel suits me because I do very little urban driving, but I do quite a lot of mileage on steep windy highways. If you want to drive around town daily then petrol would be more suitable.

Although diesel engines are more efficient, NZ's RUC system is stacked against them. So, if you buy a diesel then buy it for the torque, not for low operating costs.

Thanks for the details. Not much of a power difference, but definitely a big difference in torque.
I think I'm leaning more towards the petrol version of the vehicle at this stage now. I'm not going to be doing many KM's to justify the diesel - and if I don't move, I will be doing probably no more than around 5000-10000km a year (I live in the CBD, so very rarely need to drive)

i'd still take the diesel option for a small car in the city, purely because of the torque. feels much more responsive that the petrol. give both a try before you choose - really the fuel type and economy aren't going to make that much difference overall - especially as your initial purchase price rises :-)

For a small car, I would probably consider it, but I am looking at the 3 series type size, if I go petrol, I'll be looking at at least the 2.5 litre (so probably 325).
based on fuel consumption etc. for this size vehicle and my estimated KM/travel, it may be worth still going petrol- but if I was to go like a Yaris or something, then the diesel might be worth it then

scuwp

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#1456490 24-Dec-2015 12:57

Costs have already been covered. If it's a regular/light car or average km diesel no longer stacks up on $$$. Larger SUV's and long distances perhaps a bit better.

Get the car checked out fully. Many a repair shop has built their business off the back of used euro imports, particularly BMW. Mechanics love em to bits.

Torque is one thing on a diesel, but don't forget about the lag if it's a turbo, that can really get you into trouble around town if you're not careful. Also consider the diesel engine noise with a good test drive (including a start from cold). They are not known for being particularly quiet around town, and some even on the highway still sound like an old Massey Ferguson.

Lazy is such an ugly word, I prefer to call it selective participation

lxsw20

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#1456515 24-Dec-2015 14:12

scuwp: Torque is one thing on a diesel, but don't forget about the lag if it's a turbo, that can really get you into trouble around town if you're not careful. Also consider the diesel engine noise with a good test drive (including a start from cold). They are not known for being particularly quiet around town, and some even on the highway still sound like an old Massey Ferguson.

True of older diesels for sure, newer ones not so much. I've got a Kia Carens 1.7 6 Speed Manual diesel rental here in the UK. It doesn't really drive any different to a petrol car. Super smooth, well equiped, goes well off the line and has plenty of pick up if you need it on the motorway.

nakedmolerat

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#1456523 24-Dec-2015 14:38

Aaroona: I was looking at buying second hand and likely imported- I can't bring myself to look at new vehicles- depreciation on a new vehicle is a lot harder to swallow than on a second hand one IMO....

Fair enough, I don't like the idea of not knowing who has been in that car and what they have done with them prior :-P

networkn

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#1456526 24-Dec-2015 14:45

I have had Petrols my whole life, I scoffed at Diesel until 2010 when I was taken for a drive in a diesel 3l 3 Series BMW. I now have a 2015 Diesel 335D and I LOVE it. It's economic (Relative to performance) and it has tons of get up and go (Peel your face off). I have always owned high performance cars and this is one of the best (My favourite ever was my Audi S4 Avant 4.2l V8.

Even with Hard Driving I am getting 500-550KM to a tank of gas which costs me about $55 give or take on the day + RUC.

nakedmolerat

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#1456528 24-Dec-2015 14:46

scuwp: Torque is one thing on a diesel, but don't forget about the lag if it's a turbo, that can really get you into trouble around town if you're not careful...

I disagree with this. Driving a diesel is definitely different from a petrol car. The lag is almost non-existence in newer car.

Also consider the diesel engine noise with a good test drive (including a start from cold). They are not known for being particularly quiet around town, and some even on the highway still sound like an old Massey Ferguson.

That is the beauty about diesel. It makes sure those cyclist give-way and the pedestrian takes extra notice before crossing the road

edit: Oh and the beauty of diesel - one whole tank for me is about 900km. Less trip to petrol pump!

mattwnz

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#1456555 24-Dec-2015 15:20

nakedmolerat:
scuwp: Torque is one thing on a diesel, but don't forget about the lag if it's a turbo, that can really get you into trouble around town if you're not careful...

I disagree with this. Driving a diesel is definitely different from a petrol car. The lag is almost non-existence in newer car.

Also consider the diesel engine noise with a good test drive (including a start from cold). They are not known for being particularly quiet around town, and some even on the highway still sound like an old Massey Ferguson.

That is the beauty about diesel. It makes sure those cyclist give-way and the pedestrian takes extra notice before crossing the road

edit: Oh and the beauty of diesel - one whole tank for me is about 900km. Less trip to petrol pump!

I think it all depends on the actual brand and model of vehicle. Some of the European diesels are excellent and cutting edge technology. While if you go for a ute, they tend to use pretty old technology, and even leaf springs, and sound like a tractor. I have had a diesel ute, and it was excellent in terms of reliability, but noisy and not great handling. It only had one $1000 repair in 10 years, and services were about 300-400 per year (non dealer serviced). The big thing was road user fees and licensing fees too, which were very high. I would suggest looking at what the annual licensing fee will be too.

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alasta

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#1456560 24-Dec-2015 15:30

nakedmolerat:
scuwp: Torque is one thing on a diesel, but don't forget about the lag if it's a turbo, that can really get you into trouble around town if you're not careful...

I disagree with this. Driving a diesel is definitely different from a petrol car. The lag is almost non-existence in newer car.

I don't notice any turbo lag on mine. I'm sure there is probably some small measurable lag there, but not enough for it to bother me.

MikeB4

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#1456564 24-Dec-2015 15:33

Driving a diesel the power comes in a clump then is gone. Peak power is at much lower revs and the power band drops away fast.

networkn

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#1456644 24-Dec-2015 17:23

MikeB4: Driving a diesel the power comes in a clump then is gone. Peak power is at much lower revs and the power band drops away fast.

Heh I think you might want to come and drive my Diesel, I can assure you, you will lose your license before you notice a loss of power :)

MikeB4

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#1456669 24-Dec-2015 18:03

networkn:
MikeB4: Driving a diesel the power comes in a clump then is gone. Peak power is at much lower revs and the power band drops away fast.

Heh I think you might want to come and drive my Diesel, I can assure you, you will lose your license before you notice a loss of power :)

My main experience with diesels has been 4WD's , trucks and a few small Euro boxes

alasta

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#1456758 24-Dec-2015 20:05

networkn:
MikeB4: Driving a diesel the power comes in a clump then is gone. Peak power is at much lower revs and the power band drops away fast.

Heh I think you might want to come and drive my Diesel, I can assure you, you will lose your license before you notice a loss of power :)

Yeah, on my Mazda the torque peaks at 2,000rpm and the power peaks at 4,000rpm and both seem to taper off reasonably slowly beyond those points. Basically you just drive it at low revs all the time unless you need to overtake quickly and then you crank it towards 4,000. Easy.

scuwp

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#1456792 24-Dec-2015 21:01

lxsw20:
scuwp: Torque is one thing on a diesel, but don't forget about the lag if it's a turbo, that can really get you into trouble around town if you're not careful. Also consider the diesel engine noise with a good test drive (including a start from cold). They are not known for being particularly quiet around town, and some even on the highway still sound like an old Massey Ferguson.

True of older diesels for sure, newer ones not so much. I've got a Kia Carens 1.7 6 Speed Manual diesel rental here in the UK. It doesn't really drive any different to a petrol car. Super smooth, well equiped, goes well off the line and has plenty of pick up if you need it on the motorway.

My experience has been with 2010 -14 Euro Fords new at that time (terrible lag) and now brand new Hyundai's (better but still there) and new Outlander (not as bad as the Fords but close). Just something to check out during test drive to make sure you can manage it or it isn't a problem.

Lazy is such an ugly word, I prefer to call it selective participation

jonathan18

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#1456869 25-Dec-2015 06:18

alasta:
meesham:
alasta:
- The diesel engine is prone to the particulate filter clogging up if driven continuously for very long distances in slow stop/start conditions.

The Mazda particulate filters are designed to burn off the excess soot when driving at highway speeds, if you buy one you need to make sure you drive it for a good drive every couple of weeks. The early CX-5 diesels were particularly bad for this, when it gets clogged up the car switches itself into limp-home mode.

Yes, it's not a problem for me because I use public transport around town and my car only gets used for highway driving, but for an Aucklander using the car daily in heavy traffic it could become a problem.

For me this reason alone is enough reason to think twice about buying a diesel again; the particulate burn off is a real PITA in my Mazda 6 diesel, as I use it as my daily commute car within a small city. Also agree the figures don't stack up unless doing high-sh ks. Until RUCs are sorted, the system's against smaller diesels.

All that aside, I love the engine. Used it for towing for the first time recently and didn't even notice the heavily laden trailer attached!

Geektastic

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#1459859 1-Jan-2016 15:32

I know that (depending on fuel costs etc) it can be not as clear cut as you might think.

For example, a Land Rover Discovery with a 4.4 petrol V8 obviously has worse economy than the V6 diesel.

However....the diesel requires regular belt changes and things that the V8 petrol does not and also is well known to be prone to requiring turbocharger replacements. Add those to the total use cost and it works out very similar.

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