_What is the optimum age when investing in a classic car?

As editor of the Knight Frank Luxury Investment Index (KFLII), which tracks among other things the value of classic cars, I’m occasionally asked what is the optimum age of car to purchase.

There are two answers: one very simple, one slightly more complicated. The first, of course, is that you should just buy whatever car you fall in love with, assuming it’s at a price you can afford, drives and stops in a straight line and is not going to bankrupt you with repair bills. The second assumes that as well as enjoying your car, you will also be viewing the purchase as some kind of investment.

Given the well-publicised growth in values – according to KFLII prices have risen by 334% over the past 10 years – it’s hardly surprising that there is more of a focus on the investment side of ownership these days. And where prices rise, the funds are sure to follow – classic cars are now being touted as an asset class in their own right.

So is there an “optimum” age of car to purchase if turning a profit is part of the buying equation? Well, this is where it can get slightly geeky. Talking to my number-crunching friends at specialist insurer Hagerty, most cars tend to follow a 20 to 25-year depreciation curve. After this time values will flatten out and potentially start to increase.

The big question is how much they will increase by and how quickly prices will rise – very few cars will actually end up being worth more than they were sold for plus inflation, which is a key requirement for entry into the exclusive Historic Automobile Group International (HAGI) Top Index, which KFLII uses to track the value of classic cars.

Every car follows a different curve – provenance, rarity and less tangible factors such as “coolness” and nostalgia will determine how quickly values rise. The most expensive car to go under the hammer last year had it all.

A 1956 Aston Martin DBR1, one of only a handful built and raced by legend Sir Stirling Moss, was sold by RM Sotheby’s for $22.6m.

But rarity doesn’t have to relate to the original production run. Take, for example, the quirky and much-loved Renault 4; over eight million rolled off the production line between 1961 and 1992, but relatively few have survived – around 500 are registered in the UK – and examples in good condition are for sale online now for over £5,000 and even north of £10,000.

Early Land Rovers are also undergoing a renaissance at the moment. So much so that the Classic Works department of Jaguar Land Rover will track down a Series 1 or Range Rover model for well-heeled enthusiasts and rebuild it nut by nut – in return for a substantial amount of money.

A “Reborn” Range Rover will cost the best part of £150,000. Of course a car that was produced in very small numbers in the first place will see its value appreciate much more quickly. The glorious Ferrari 250 GTO, of which only 39 were produced between 1962 and 1964, was selling for over its purchase price of $18,000 plus inflation by 1976, according to Hagerty’s Brian Rabold.

A fine racing pedigree helped and the model now holds the record for most expensive ever to sell at auction – $38m in 2014 – with cars reportedly sold privately for over $40m.

But is it possible for the impatient investor to bypass the depreciation curve altogether and see a return on their classic car investment immediately? The good news is that the answer is yes. The bad news is that you’ll need rather deep pockets and the right connections.

A new breed of hyper car is bucking the depreciation trend. Rather than shedding a bucketful of value as soon as they roll out of the showroom like most vehicles, these rare, extremely expensive and highly sought-after – forget about buying one if you’re not already a VIP customer – special editions are seeing their values rise from the get go.

A trio of cars launched in 2015 – the Porsche 918, McLaren P1 and La Ferrari – kick-started the “instant classic” phenomenon with prices for each model doubling within just 12 months. More recent launches such as the LaFerrari Aperta, Bugatti Chiron and Porsche 911R look set to follow the same journey. An Aperta sold for a sizzling $10m at a charity auction last year.

There is a catch of course. As HAGI’s Dietrich Hatlapa points out, the novelty of these cars when bought as investments is all in their newness – every mile or kilometre on the speedo will see their value fall. It’s a life of air-conditioned pampering, not the grit of the track, for these modernday monsters, which somehow seems to defeat the object of owning a tarmac-chewing sports car.

Nick Mason – 250 GTO owner, legendary Pink Floyd sticks man and dedicated amateur racing driver – summed it up neatly when we chatted about cars recently. “It’s a bit like buying wine even if you don’t like it. Cars need to be driven.”

So with that bit of advice ringing in your ears, the choice is yours. Get a new car that may rocket in value, but you can’t drive; or buy something that stirs your soul. If it rises in value, that’s great, but it’s the ride and cherished memories behind the wheel that will be your lasting investment.

Andrew loves talking about luxury investments and in particular classic cars.

To find out more about the KFLII email Andrew Shirley.