How to calculate future depreciation?

[sam303]

What's the best way to calculate future depreciation on a car I am thinking of buying?

Trying to weigh up total cost of ownership and obviously depreciation is going to be a major factor, but after various internet searches and trying online calculators I still haven’t found any way of calculating future depreciation. best I can do is assume a 15% reduction in value per year, but that's a bit finger-in-air. Really I'm trying to work out whether I should be buying a diesel: although there is a premium on buying a diesel, this is offset by the fact that you will receive a premium when you sell it, so to arrive at a true picture of the cost I need to know what the difference between buying and selling price is likely to be. Key facts:

- looking at used cars 5 to 10 years old
- budget of around £10k
- approx 9,000 miles per year
- term of ownership 2 years

So if I was looking at, say a 2006 XC90 at £10k how do I best calculate the depreciation that I will experience over the next 2 years, for both a petrol and a diesel version?

All help appreciated!

[ewenm]

You can't calculate it but you could estimate it. In your example, I'd try to find a 2004 model (if it exists) with roughly the predicted mileage and see what that is being advertised for.