In 2015, people owned their new cars an average of six-and-a-half years, a full two years longer than in 2006. The average age of cars currently on the road is about 11.5 years old, IHS Automotive reported.

By 2020, that number is expected to increase 15 percent. People are holding on to their cars longer because they are much more reliable than they were in the past. So, are Porsche owners also keeping their cars longer?

We know they’re buying more of them. According to Porsche Cars North America (PCNA), U.S. sales continue to increase. In 2016, 54,280 Porsches were sold in the United States, which was "a new record for U.S. Porsche sales and an increase of 4.9 percent over 2015."

A big part of the increase was due to sales of the compact SUV Macan, which saw a 30 percent boost in December 2016 over December 2015. In addition, Consumer Reports recently recommended 100 percent of the vehicles it tested from Porsche.

People love their Porsches. But what keeps them from trading up to a newer model?

For those who can afford high-end sports cars, there’s likely very little that keeps them from purchasing a new model every few years. It’s not just the lure of the new car smell. Older vehicles require more work, and once the warranty expires, expenses increase. Plus, it’s more convenient to have a car you can rely on every day.

I recently spoke to the owner of an independent Porsche shop in Connecticut who has owned, by his estimation, about 50 Porsches over the course of 35 years. At one point or another, he has owned nearly every model of 911.

Of course, he’s the exception. The majority of Porsche owners don’t own his type of business and won’t even come close to having access to the number of cars he encounters on a weekly basis. But there are many individuals who have the luxury of purchasing multiple Porsches in their lifetime.

Then there are those who simply get attached to their vehicles. PCA’s Panorama magazine often spotlights individuals who have lovingly cared for their vintage vehicles for years. Many own them until their deaths. There is a sentimental connection that keeps them bonded.

I own a 1976 911S that I’ve had for about five years. It’s not a new car, so the six-and-a-half-year statistic mentioned previously does not apply. I don’t have the wherewithal to trade it in for a newer 911, but that’s not what’s keeping me from selling it for something spiffier and shinier.

It’s my first Porsche, and it needs a bit of work. The paint is flawed, the suspension is not as stiff as it should be, and it’s leaking a bit more oil than it should.

But "Smoky" runs well overall, and someone needs to preserve the history of these vehicles. While it may take me a few years to make him concourse-ready, he will be lovingly cared for and driven with passion.

I have no plans on ever selling Smoky. There will be no upgrade. Do I envision myself buying a second Porsche? Absolutely. One with power steering would be nice. But in the meantime, I’m satisfied with the one I have.