Help with Man Maths (brain freeze)

[JohnBender]

Need help with some man maths;

Audi A6 (circa 2005/6) 3.2 diesel v petrol
All figures rounded up/down to nearest whole number.
Also using average pump prices and manufacturers claimed mpg figures

80 litre tank (17.5 gallons?)
Cost to fill:
Petrol £108 @ £1.35
Diesel £113 @ £1.42

Diesel
urban 33mpg = range 577 miles
xtra 45mpg = range 787 miles

Petrol
urban 26mpg = range 455 miles
xtra 34mpg = range 595 miles

So in theroy, my extra £5 at the pumps gets me an extra 122 miles urban, and an extra 192 miles extra urban.

The driving will be a mix of both.

Now here's the brain freeze bit:

There is £4000 difference bewteen the two cars I have been offered (almost identical in every other way).

How many miles need to be racked up before the extra outlay in buying the diesel before it balances out?

The diesel appeals, if nothing the else for the gains in bhp & torque from a remap, but is that worth the extra £4k outlay up front?

[Hugo a Gogo]

you've worked that out the most complicated way possible

say average between urban and extra:
D - 39mpg
P - 30mpg

D 1.40 per litre = 6.36 a gallon
P 1.32 = 6.00

D 0.163 a mile
P 0.187

2.5p a mile difference

= a metric fk-load of miles to break even

about 180,000

not counting residuals, or tax, or insurance, I dunno about that
or
http://www.virtualcarsuperstore.co.uk/petrol-diese...

[wheedler]

Don't worry much about the extra outlay, the 4000 is small price to pay not to hear no one wants petrol Sir, when it's time to sell.

[lostmotel]

Quick back of the envelope calculation suggests nearly 100,000 miles.

Consider the following:

£108 buys you (going on urban) 455 miles in the petrol. £113 buys you 577 miles in the diesel. We need to compare these in terms of mileage. So 455 miles in the diesel costs you (113/577)*455 = £89.11. So you save 103-89.11 = £18.89 if you drive 455 miles. 4000/18.89 = 211, meaning to make back £4000 in the diesel means you need to drive 455 miles 211 times = 96,347 miles.

I think that's right...

[Hugo a Gogo]

JohnBender said:

The diesel appeals, if nothing the else for the gains in bhp & torque from a remap, but is that worth the extra £4k outlay up front?

and if that knocks your MPG down?

[300bhp/ton]

JohnBender said:

The diesel appeals, if nothing the else for the gains in bhp & torque from a remap, but is that worth the extra £4k outlay up front?

Remember some of the extra £4k will be recouped come resale time. I don't know figures for sure, but I suspect the percentage difference in value will remain fairly constant and only go in the diesels favour.

So more outlay + more money back later on.

[wheedler]

300bhp/ton said:

Remember some of the extra £4k will be recouped come resale time. I don't know figures for sure, but I suspect the percentage difference in value will remain fairly constant and only go in the diesels favour.

So more outlay + more money back later on.

But that's not man maths is it?
Also, looking online at the 3.2 v6 seems a few issues with them, also not PH maths either.

[GAjon]

This is a blatant waste of man maths, which should only be used to explain to your wife or girlfriend why a RS6 is the best value all round.

[JohnBender]

GAjon said:

This is a blatant waste of man maths, which should only be used to explain to your wife or girlfriend why a RS6 is the best value all round.

[Pablo68]

wheedler said:

Don't worry much about the extra outlay, the 4000 is small price to pay not to hear no one wants petrol Sir, when it's time to sell.

What a bizarre way to lead your life. Do you worry about the resale price of everything you buy? Seriously would you buy a house you didn't like over one you did because you might get a bit more for it in 10 years time? Do you buy your clothes based on what looks good and feels good to wear or on which will get more at the second hand shop in a few years time? Surely unless you are buying just to sell on for a profit, and as long as you can afford it, buy whatever will give you the most pleasure during its ownership is the best option?

[300bhp/ton]

Pablo68 said:

wheedler said:

Don't worry much about the extra outlay, the 4000 is small price to pay not to hear no one wants petrol Sir, when it's time to sell.

What a bizarre way to lead your life. Do you worry about the resale price of everything you buy? Seriously would you buy a house you didn't like over one you did because you might get a bit more for it in 10 years time? Do you buy your clothes based on what looks good and feels good to wear or on which will get more at the second hand shop in a few years time? Surely as long as you can afford it buy whatever will give you the most pleasure during its ownership is the best option?

Surely this follows with purchase price though? And running costs.

Assuming many people only keep a car 12months - 3 years at a time. Then depreciation can be one of the biggest costs, not too mention ease of selling on.

I wouldn't say it should be the prime motive behind a purchase, but it should come into it, as it'll likely affect what you can or can't buy when you do replace it.

[Pablo68]

300bhp/ton said:

Surely this follows with purchase price though? And running costs.

Assuming many people only keep a car 12months - 3 years at a time. Then depreciation can be one of the biggest costs, not too mention ease of selling on.

I wouldn't say it should be the prime motive behind a purchase, but it should come into it, as it'll likely affect what you can or can't buy when you do replace it.

It does for some. Honestly I buy things to enjoy them and as long as I can afford them I tend not to consider the resale value...especially as there are often too many variables to actually know what the resale value of something may be in 1, 5, or 10 tens or so. Otherwise you just spend the entire time wishing you had bought what you actually wanted rather than what was the "best buy" value wise. Resale value is for stuff you actually intend to make a profit on, shirley?

[wheedler]

What's so "bizzare" about it? A car is not a house, "bizzare" is you thinking it is

[JohnBender]

To make things easier:

I have been offered the Diesel for circa £9000
The petrol for circa £5000

Assuming a run it for 1 - 2 years, I'm not too worried about depreciation.

Is the diesel worth shelling out an extra £4k up front, which I may/may not see most of it back come re-sell, but neither car has much further to fall now.

[Pablo68]

wheedler said:

What's so "bizzare" about it? A car is not a house, "bizzare" is you thinking it is

No but a car is something you spend a lot of time in.

Do you prefer to spend a noticeable amount of your time in something you enjoy being in or something that you might get more for when you eventually sell it?

[lestershaw]

i think resale value and residuals should be partly offset by joy and experience of ownership. If you actually enjoy the petrol car you have chosen over a diesel, then a possible £3000 saving over 3 years comes to about £20 a week, a small price to pay i would say.

[wheedler]

JohnBender said:

To make things easier:

I have been offered the Diesel for circa £9000
The petrol for circa £5000

Assuming a run it for 1 - 2 years, I'm not too worried about depreciation.

Is the diesel worth shelling out an extra £4k up front, which I may/may not see most of it back come re-sell, but neither car has much further to fall now.

No it's not. If you were spending 20k+ then possibly yes

[Pablo68]

JohnBender said:

To make things easier:

I have been offered the Diesel for circa £9000
The petrol for circa £5000

Assuming a run it for 1 - 2 years, I'm not too worried about depreciation.

Is the diesel worth shelling out an extra £4k up front, which I may/may not see most of it back come re-sell, but neither car has much further to fall now.

If it was me I would decide based on which I would prefer to spend a considerable amount of the next X years sat in.

[blueg33]

I have a 3.0tdi A6. You will not get 47mpg as an average ever. Best I have seen is 42mpg on a long mway run, my car current average is 35mpg. I have done 90k miles in it

[300bhp/ton]

JohnBender said:

To make things easier:

I have been offered the Diesel for circa £9000
The petrol for circa £5000

Assuming a run it for 1 - 2 years, I'm not too worried about depreciation.

Is the diesel worth shelling out an extra £4k up front, which I may/may not see most of it back come re-sell, but neither car has much further to fall now.

No!

And it's almost folly to justify a vehicles cost based on recouping it via fuel. This will never work.

Buy the diesel if you "want" the diesel. But buy if because you like the noise, power delivery with the added bonus it'll be better on fuel. Don't buy it under the (delusional??) belief that it'll be cheaper overall.

That said, if you can afford £9k instead of £5k on a vehicle you might want to consider what other petrol cars £9k might get you