Best and worst…. residual values

Cars lose value over time, there's no getting away from it. In fact, depreciation is the biggest cost of ownership, so knowing which cars hold on to most of their value could save you a packet.

Here at whatcar.com we have resale values for every new car on sale, so arm yourself with the numbers you need with our depreciation tool – before heading into battle on the forecourt.

To make it easier, we've crunched the numbers to reveal the car with the best overall resale percentage, and the one with the worst.

Strongest resale percentage
The Porsche 911 has the strongest three-year resale value of any car currently on sale – at 64% for a GT3.

The car isn't cheap, of course, with a list price of more than £86,000, so although it will still be worth just over £55,000 after three years, you'll have to reconcile yourself to losing £30,539 over that period.

Weakest resale percentage
Citroen's C6 executive is at the bottom of the class and can't even hold on to a fifth of its original retail price after three years on the road.

Even though it's more than half the price of the Porsche, at £37,895, it sheds £30,420 in three years. That depreciation leaves you with a car worth just £7475.

The executive car market is a ruthless place that's packed with incredibly impressive models, so the C6 really suffers. It's not a bad car, though, so has the potential to be a great, quirky used car bargain.

Least cash lost
Spend a small amount of money on a new car with a reasonable resale value and you'll not suffer as much in the wallet.

At £6995, the Kia Picanto hits both nails on the head with its residual value of 43%.

That means it sheds just £3995 over three years and should still be worth £3000.

The Volkswagen Fox costs £500 more to buy, loses a little more at £4095, but is worth £3350 over the same period.

Most cash lost
So, which car do you think you could sell for more than £42,000 for after three years, but still have accumulated a loss of more than £115,000?

The answer is the absurdly powerful 65AMG version of the Mercedes-Benz SL roadster.

It might be a brilliant, fast car, but the second-hand market isn't great for the 603bhp SL, so it drops nearly three quarters of its original £157,510 purchase price, holding on to just 27% of what you paid for it.

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