Does a diesel vehicle (car) still stack up?

Forums › Transport (cars, bikes and boats) › Does a diesel vehicle (car) still stack up?

Aaroona

3196 posts

Uber Geek

#189289 22-Dec-2015 18:17

I've been looking around at a new (used) car to spoil myself.
I'm currently looking at two vehicles, one is diesel and the other is petrol.

I know back a few years, Diesel was considered a great purchase (in general) for cost of travel per/km (repairs aside), and I am wondering if this is still the case?

Has anyone purchased a new vehicle recently? what made you choose diesel over petrol, or petrol over diesel.
Is there anything I should consider when looking at Diesel vs. Petrol? Are the repair costs generally higher for one over the other still?

Realistically I'm probably going to put around 10000km-14000 in the first year of ownership (I will be of course finding excuses to use it, while the novelty wears off)

1 | 2 | 3

20143 posts

Uber Geek

#1455539 22-Dec-2015 18:22

You hear conflicting stories that they are better than petrol cars for emissions, then they are worse. The VW scandal possibly hasn't helped diesel reputation. They do tend to have better torque than petrol though, so I find them good for hill driving.
I have just got rid of a diesel, and replaced it with petrol. Mainly because the road user charges were so high. If I was only doing 10k I wouldn't buy a Diesel. They are also more expensive to maintain, in my case about double petrol. For some you also have to drive them regularly on highways to keep the air filters clean.

gbwelly

1243 posts

Uber Geek

#1455540 22-Dec-2015 18:29

Diesel only stacks up if you are carrying heavy loads or can disconnect the odometer.

MikeB4

18435 posts

Uber Geek

ID Verified

Trusted

#1455546 22-Dec-2015 18:42

Diesel is good for trucks and 4WD real SUV's due to the usually higher torque and peak power at lower engine revs, Also good if you are towing say boat or caravan.

If you are travelling long distances over a year there is an advantage with diesel. If you do low to average KM's and a lot of city driving stick with petrol or electric/hybrid.

If you get a diesel absolutely do not disconnect the odometer to cheat the RUC's

Jase2985

13459 posts

Uber Geek

ID Verified

Lifetime subscriber

#1455547 22-Dec-2015 18:44

http://www.transport.govt.nz/assets/Uploads/Our-Work/Documents/petrol-vs-diesel-calculator-2015.xls

try that and then compare them

Aaroona

3196 posts

Uber Geek

#1455556 22-Dec-2015 18:56

Thanks for the replies all.

I will likely be doing mostly city mileage, a smallish amount of highway travel and maybe a road trip or two (~500km).

It's sounding like petrol may be a goer - however, based on that spreadsheet from the govt, the cost of the diesel still seems to come out around $600 cheaper, over the course of 14000km. But i guess that may very well be evened out by he cost of repair for the diesel.

The torque would have been nice, and unfortunately it's not quite apples v apples in terms of the vehicles I am looking at, so that makes the choice a little difficult. But I'm not seeing any huge benefits of going diesel (other than the torque, and potential fuel saving)- $600, while not a small amount of money, could be justified to have a more "fun" vehicle, which I am looking at.

I shall do some more reading around, but I definitely agree- for a vehicle that would be traveling tens of thousands of km's a year, then diesel might be worth looking at, but at my rate of travel, may not be a huge deal.

xlinknz

1127 posts

Uber Geek

Trusted

#1455559 22-Dec-2015 19:00

As others has mentioned

1. The generally accepted rule is if you more than 14K per annum you are better off with a diesel taking into account RUCs
2. Diesels have more torque i.e. more powerful at lower rpm and better for towing
3. Arguably cleaner than petrol [esp if you use biodiesel]

Small diesels [<2.0] can be highly fuel efficient more so than hybrids esp. on open road [extra urban]

We have a diesel and have no regrets, our next vehicle will be a [petrol] hybrid or more likely electric

mattwnz

20143 posts

Uber Geek

#1455561 22-Dec-2015 19:03

Aaroona:

You may also want to look at depreciation as that is a cost. For example european cars tend to depreciate faster than japanese types I have found from personal experience. A popular car often holds it value better.

Equinox IT

Cloud spending continues to surge globally, but most organisations haven’t made the changes necessary to maximise the value and cost-efficiency benefits of their cloud investments. Download the whitepaper From Overspend to Advantage now.

Aaroona

3196 posts

Uber Geek

#1455562 22-Dec-2015 19:05

mattwnz:
Aaroona:

You may also want to look at depreciation as that is a cost. For example european cars tend to depreciate faster than japanese types I have found from personal experience. A popular car often holds it value better.

THat's a good point - both cars I am looking at are European - BMW to be exact, which aren't exactly great for holding value (being quite honest), but I have loved driving them (had an entry level 3 series previously, plus used a 5 series and Z4 in the past).

alasta

6703 posts

Uber Geek

Trusted

Subscriber

#1455604 22-Dec-2015 19:44

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.

Aaroona

3196 posts

Uber Geek

#1456463 24-Dec-2015 11:55

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)

nakedmolerat

4629 posts

Uber Geek

Trusted

Lifetime subscriber

#1456467 24-Dec-2015 12:04

Aaroona: ... I will be doing probably no more than around 5000-10000km a year (I live in the CBD, so very rarely need to drive)

Diesel is not for you if that is the case.

You will need at least 14000km a year to actually enjoy the cheap fuel cost (I did thorough calculation and even include the higher Rego cost etc when I was looking to replace my car last year). Less than that, you will be spending more than what a current fuel efficient petrol of the same class.

With regards to filter clogging up if you were to use it around town - it was a problem but not so much with the newer diesel range.

The other thing you need to be aware of (probably does not apply to you as you are buying a nz brand new car), I would be very cautious with second hand diesel. Diesel need regular and good service records to maintain the engine.

meesham

973 posts

Ultimate Geek

#1456468 24-Dec-2015 12:08

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.

Aaroona

3196 posts

Uber Geek

#1456469 24-Dec-2015 12:09

nakedmolerat:
Aaroona: ... I will be doing probably no more than around 5000-10000km a year (I live in the CBD, so very rarely need to drive)

Diesel is not for you if that is the case.

You will need at least 14000km a year to actually enjoy the cheap fuel cost (I did thorough calculation and even include the higher Rego cost etc when I was looking to replace my car last year). Less than that, you will be spending more than what a current fuel efficient petrol of the same class.

With regards to filter clogging up if you were to use it around town - it was a problem but not so much with the newer diesel range.

The other thing you need to be aware of (probably does not apply to you as you are buying a nz brand new car), I would be very cautious with second hand diesel. Diesel need regular and good service records to maintain the engine.

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.
Definitely agree on the service records though -I'm pretty picky on that. My last vehicle which was imported from the UK had a full service history, but was also a petrol.

Regs

4066 posts

Uber Geek

Trusted

Snowflake

#1456472 24-Dec-2015 12:13

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 :-)

Sales Engineer
Snowflake
www.snowflake.com

about.me/nzregs
Twitter: @nzregs

alasta

6703 posts

Uber Geek

Trusted

Subscriber

#1456483 24-Dec-2015 12:34

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.

1 | 2 | 3