- Sat Nov 23, 2013 7:51 pm
#3711540
karl wrote:No I haven't. I chose cars with as near as possible matching performance. The 1.2 diesel is 13.9 sec vs 11.9 and it is 10ps shy. The two I picked are 0.4 sec apart in performance and only 5ps apart.cheapskate wrote:you've deliberately chosen the more expensive 1.6 to make your calculation work, why not try it with the more evenly matched 1.2?karl wrote:the high MPG of dervs has saved me an absolute fortune over the years. I could, of course, take extreme metrics to calculate a fixed 'variable' in order to convince myself that my petrol car was cheaper to run, but I'm not Flipping stupid, I own a derv and am well aware of the savings :salut:Here are the figures and calculation method I used. Do please identify the 'extreme metrics':
From the VW site I chose petrol and diesel models that were within 5ps of each other. I took the combined cycle fuel economy figures as stated by VW and calcualated the the total cost of the fuel required to do 100K km. I used VW statement of the tax band to work out the total tax for each car for 5 years assuming 20K Km per year. So purchase price + fuel cost + tax = total.
http://www.volkswagen.co.uk/new/polo-v/ ... s/overview
I got the fuel price from the BBC website:The average price of petrol in the UK is about £1.30 a litre or £1.37 for dieselSo; the figures for the 1.4 85PS are:
Purchase price £13,520
L/100K 5.9
Fuel used 5900 L
cost per L £1.30
Total Fuel cost £7,670
Tax for 5Y £625
Total cost £21,815
For the 1.6 TDI 90Ps
£16,415
4.6
£1.37
4600 L
£6,302
150
£22,867
Where have I exaggerated or made an error?
As for matching the cars - I would have gone for an exact HP match but that wasn't possible. The acceleration times for the two cars are 11.9 sec and 11.5 respectively so they are a reasonably close performance match.
The cost savings for diesels are a myth as far as I am concerned, unless you can show me the numbers that would indicate otherwise.
My other Honda runs on grass.....cuts it too.