You see evidence of this every time the price of gas spikes and you hear stories of people jumping to trade their gas-guzzling SUV for something more economical. Even when gas prices spiked to $1.40 per litre, making $100 fill-ups more common, taking a depreciation hit to trade earlier than you would have otherwise makes little financial sense unless you drive a LOT of kms. The fuel cost you will save over a year will be minor compared to the cost of the new vehicle. I honestly think it's because the closest tangible depreciation cost (measured monthly by your car payment) is usually an automatic withdrawal where people see the cost of fuel every time they fill up.