It all boils down to altitude.
Let's say you've just moved here from Illinois. You're all settled in, you know where your favorite micro-breweries are, and you're still sending pictures of dispensaries to your friends back home. Then, one of them asks, "Have you been to (insert popular mountain town here)?" So you get the impetus to grab a local friend and take a drive. You pack up your trusty Subaru and blast down I-70. It seems like all is well, at least until you start climbing hills in the mountains and you start losing speed. So you mash the gas, the transmission downshifts, and the engine begins to hit the high notes yet your speed increases very slowly.
At this point, you might be thinking, "Is there something wrong with my car? This isn't that big of a hill. Why is it so slow?" Well, the answer is altitude. The theory is simple: in an internal combustion engine, air and fuel are mixed and combusted, sending the piston down the cylinder bore. The piston, which connects to the crankshaft via a connecting rod, then turns that motion into a rotational force that is transmitted to the wheels through the car's driveline. If the combustion lacks either fuel or oxygen, the explosion will be less explosive and create less power—think about what happens to a candle when you "suffocate" it—and in Colorado, we have quite a bit less oxygen in the air.
That means your car has less horsepower the higher you go. Generally, you'll lose three percent for every 1,000 feet you climb. If your car had approximately 200 horsepower at sea level, in Leadville (elev. 10,152 ft.), you've only got 140 horsepower and that's enough to feel. Yikes! What can you do to get your ponies back? The answer is turbocharging. Turbochargers use exhaust gasses to spin a compressor wheel, which is attached to another compressor wheel that forces more air into the engine. That means the turbocharger can stuff the engine full of our thin air to make things more like they would be a sea-level and make adequate power.
So if you're in the market for a new vehicle and are looking for effortless mountain travel look for something turbocharged, many SUVs are starting to feature turbocharged powerplants—including the Mazda CX-9, the Audi Q5, the Ford Explorer Eco-boost, and the GMC Terrain, just to name a few.
What are your thoughts? Did you notice your car was down on power when you came here? Did you upgrade to a turbo? If so, let us know how much of a difference that made in the comments below!