From Parkers Online.
In any case, the economy is a relatively minor component of the overall expense of running a car. The Saxo VTS has a 3-year depreciation index of
0.45. Assuming a typical 3-year ownership period, the cost of depreciation would be £6600, the cost of fuel approx £3600 and the cost of tax etc.. would be ~£500. Averaged annual cost = £3580If the economy was the same as the Mini, that would change to approx £3400, i.e. by about 5%.
As a side note, this comparison is unfair. The VTR is a more suitable model for comparison with the Mini - it offers virtually identical performance and fuel economy, but costs nearly £2k less to buy and is significantly more practical.