How is a diesel car more expensive to run?

[ZephyR]

Very interesting and quite heated in places. I'm not a diesel fan and never have been, but as I've never owned a diesel car what do I know.
One thing I can say is that all through this thread people are comparing one model against another and making comparisons about their value. But in most of these cases it is like comparing apples with bananas. You are not genuinely comparing like for like.
There is no point in comparing residual values, running costs, insurance etc. between a car that does 0-60 in 8 seconds and one that does it in less than 7 seconds. Clearly all of these are going to be different.
Likewise in comparing the 140TDI against the 1.4 (160) there is a significant performance difference. And in motoring terms extra performance always costs more. Fact.

A comparison between the 170TDI and the 1.4 (160) would be a better match on performance levels. Only 1.7% difference on residual here by the looks of it. But even here there are differences. You are comparing a GT spec car with various extras including leather seats against a car with a more basic spec. Leather seats and full air con will always help sell a car so its residuals will consequently be more anyway.

At today's prices the 1.4 (160) costs £21,670 and the 170TDI costs £25,950. A price difference of £4,280.
If you took VW finance @ 7% the extra £4,280 would cost you £300 per year, £900 over 3 years. So you are paying £5,180 more for the 170TDI over 3 years.
Balanced against that the 1.7% extra residual value of the 170TDI is a petty £441 at the end of 3 years.

So how many tank fulls of fuel would you need to make up that kind of difference? And on top of that the insurance for the 1.4 (160) is usually less than for the 170TDI.

[tony4147]

Sensible post, and the previous.
I don't do the mileage hence why I bought the TSI, if I did the miles I would buy the TDI, you buy a car to suit YOUR needs.

I've had many a car that were supposed to have strong residuals until the day I come to sell and there not a strong as I was to believe.

It's all personal preference!

[Mark V]

Zephyr - I do appreciate your point re performance but I also think to be fair on the 160 to 170 comparixon you would at least need to factor in the options needed to make their specs the similar - OK maybe ignore the 'free' leather but consider 18"s, fogs, ACC, dual-zone climate etc as these are apprecialble differences.

[ZephyR]

Yes you’re right Mark about the cost of those extras and they need to be taken in to account. However I suspect that when leather, Interlagos and full aircon are added on to a 160 TSi its residual value will be equal to the 170 if not slightly better.

Anyway here’s my best shot at getting a fair comparison -
The cost of adding Leather, Interlagos wheels, rear tints, 2 zone climate control, fogs and ACC makes a 160 cost £25,590, almost as much as a 2.0 TSi which doesn't give a realistic figure to compare.
However comparing the 140 TDI to the 140 GT TDI the extra cost of all those extras is £2,550.
So a theoretical 160 GT TSi would be £21670 plus £2,550 = £24,220.
The 170 GT TDI is £25950.
A difference of £1,737 more for the diesel.
3 years interest @7% on £1,737 = £363 making a total price difference of £2,093 more for the 170 TDI.

Now for the fuel costs. Assuming an annual mileage of 10,000 miles per year, using VW’s quoted urban mpg figures and taking unleaded at £1.31 and diesel at £1.39 I work out that fuel costs £334 more per year for the 160 TSi than for the 170 diesel to cover those 10,000 miles. Over 3 years that’s £1,002 less for the diesel.

The 170 TDI cost £2,093 more to buy, minus the fuel savings of £1,002 means that over 3 years the diesel actually cost £1,090 more than a theoretically similar 160 TSi over an average 3 years.
Obviously variations in annual mileage and types of driving will affect these figures but they should be a fair average.
Please let me know if I've made any errors in my calculations.

[RisingRoc]

8p is quite a gap in fuel prices. I tend to see closer to 4p or 5p at the moment. Obviously this various geographically.

[Cuprabob]

It's around 8p up here in Scotland at the moment.

[RisingRoc]

It's around 8p up here in Scotland at the moment.

Not in Glasgow

[Cuprabob]

I filled up yesterday in Ayr and it was £1.309 for petrol and £1,389 for diesel.

I was in Glasgow last week and remember looking at the board in Tescos in Springburn and it was only 7p difference.

I've not seen it as low as 5p for a long time.

Where abouts are you seeing the difference and is it because petrol ismore expensive or is it the diesel that is cheaper?

[RisingRoc]

Saw petrol 1.34 and diesel 1.39 in the west end and Renfrew way yesterday.