Where did you get a 20-30% average depreciation on cars? Depreciation is not linear on vehicles. Most of the depreciation occurs in the first few years and then tapers off. Is this calculated into your algorithm?
Like someone else mentioned, there are better tools to calculate static ownership costs. This is definitely a good start.<p>I'm working on <a href="https://www.maintenr.com" rel="nofollow">https://www.maintenr.com</a> and we allow you to calculate your service and fuel expenses dynamicly.
The other week I was thinking about buying a car to save money on commuting... And I'm sure I am not the only one.<p>I definitely see value in this tool. I have 0 experience with cars, and I am sure I have no idea how much does it cost to maintain, repair. Again, I don't think I am the only one. So is £20 or so worth paying to get accurate numbers, tweaked for a specific country, with nice explanations why and how? I think so ;)<p>I would really consider experimenting to see if this could be monetized, whether people are willing to pay. It won't make millions, but as a passive income source? That might work.
Nice idea, but I actually think Edmund's TCO is a bit more comprehensive and uses real world data for each car.<p><a href="http://www.edmunds.com/porsche/911/2011/tco.html?style=101380348" rel="nofollow">http://www.edmunds.com/porsche/911/2011/tco.html?style=10138...</a>