Exotic car depreciation and your loan: reading the numbers

The depreciation table shows how much value various exotic and luxury models have lost over five years, from two kinds of iSeeCars data, plus a few Hagerty collector-market figures. The study numbers come from real sales; the model-page numbers are estimates. The Porsche 911 shows 11.1% in one and 5.3% in the other, and the difference matters if you’re using either to size a loan.

Two kinds of iSeeCars figure

The rows marked as the study come from the iSeeCars 2026 cars-that-hold-their-value study. Its methodology says it analyzed over 950,000 five-year-old used cars sold from March 2025 to February 2026, excluded low-volume and discontinued models, and adjusted MSRPs to 2026 dollars. These are averages of what actual five-year-old cars sold for, compared with what they cost new. The page doesn’t show a publication date, so we cite the sales window.

The rows marked modeled come from iSeeCars’ per-model resale pages, such as the Ferrari Roma’s. Those pages say iSeeCars analyzed over 15 million vehicles and used the automaker and segment in a mathematical model to estimate resale value. They carry no date. Some of these cars, the Roma and the Maserati MC20 among them, haven’t been on sale long enough to have five years of real resale history, so their five-year figure is a projection, not an observation.

So the study tells you what happened to a specific group of cars over a specific window, and the model page tells you what a formula expects. Neither tells you what your car will do.

Why the 911 has two numbers

The study found the 911 lost an average of 11.1% over five years, or $15,533. The 911’s model page shows 5.3%. Our table uses the study figure for the 911 because it’s built on observed sales in a stated window, and we mark which source each row uses. If you want to see the more optimistic case, enter the modeled rate by hand.

Same company, same model, and one figure is less than half the other. Keep that in mind before you lean on any single depreciation number.

Hagerty’s rows are something else

The table also lists three cars from Hagerty’s Price Guide update of October 1, 2026, published October 8: the 2010 to 2012 Porsche 911 GT3 (997.2) up an average of 64%, the 1990 to 2001 Lamborghini Diablo VT up 40%, and the 1994 to 1999 Ferrari F355 up 19%. Those are value changes over a single quarter in the collector market, calculated across all conditions. They are not new-car depreciation, they cover one quarter rather than five years, and the calculator doesn’t use them as presets.

Hagerty described the market as split, with exotics and modern Ferraris rising while more attainable enthusiast cars “have begun to tread water or deflate.” Its Market Rating for September 2026 was 58.73, down 0.01 from the month before, in the 50 to 60 band Hagerty calls a flat market. A few models jumping in a quarter while the overall index sits flat is what Hagerty means by split, and it’s a good reason not to plan a loan around one quarter’s gain.

How the calculator converts five years to one

The calculator’s value line needs a yearly rate. It converts each five-year loss with this formula:

yearly change = (1 − five-year loss)^(1/5) − 1

For the 911’s 11.1%:

1. 1 − 0.111 = 0.889
2. 0.889^(1/5) = about 0.9767
3. 0.9767 − 1 = about −0.0233, or −2.3% a year

Check it the other way: 0.977 to the fifth power is about 0.890, so a car losing 2.3% a year keeps about 89% of its value after five years, which is the 11.1% loss the study reported (the small gap is rounding). A $200,000 car at that rate would be worth about $178,000 after five years.

For comparison, the 911’s modeled 5.3% works out to about −1.1% a year, and the Taycan’s 54.7% study figure to about −14.6% a year.

Dividing by five would be wrong. 11.1 ÷ 5 = 2.22% looks close here, but on fast-falling cars the gap gets large: 54.7 ÷ 5 = 10.9% a year, against the 14.6% the compounding formula gives. Value changes compound, so the yearly rate has to as well. Inside the calculator, the yearly rate is applied month by month, so the line is smooth rather than stepping down once a year.

What the conversion assumes

It assumes the car loses value at an even rate every year. Real cars rarely follow a smooth curve, and the Hagerty rows show older cars jumping in value inside a single quarter. A five-year average applied over 15 years is a simplification, which is why the calculator lets you type your own rate, including a positive one for a car you expect to appreciate.

It also assumes the price you pay is the car’s value on day one. If you’re paying over market, start your value line lower.

Using the table with a loan

Pick the closest model in the calculator, then try a faster rate from further down the table to see how much margin you have. If the shaded area appears, that’s the stretch where you’d owe more than the car would likely sell for. The long-term loan guide works through a 911 against a Taycan on a 144-month loan, and the balloon guide shows what a fast curve does to a balloon at the end. Past values don’t predict future ones; use the figures to test a plan, not to forecast a price.