Tesla is about to report earnings - but no one will talk about its biggest competitive advantage

Tesla will report fourth-quarter 2016 earnings after the bell on Wednesday. And with Wall Street struggling to figure out the company's financial composition after the SolarCity merger, earnings are likely to be weird.

Analysts will obsess over how many vehicles Tesla expects to build and delivery in 2017, whether the carmaker will launch its $35,000 Model 3 on time later this year, what the cash-burn situation looks like. And perhaps analysts will even touch on the actual financial results, which are anticipated to be a big quarterly loss.

In the flurry of confusion that will define this earnings report, Tesla's biggest and most important competitive advantage is going to be missed.

It's the Supercharger network, Tesla's fast-charging infrastructure which used to be free to all owners, but will now cost a bit for new owners (understandably as Tesla can't afford to give away charging to the nearly 400,000 customers who have pre-ordered the Model 3).

There really is no substitute for Supercharging, which can re-juice your Tesla in about an hour, restoring the 200-plus-mile range the automaker's cars boast. I took an ill-fated road trip in a Model S sedan last year during which I experienced the full gamut of Tesla charging options. I charged the car using a wall socket (1 mile per hour of recharge), a Tesla partner charging station (non-Supercharger, slower, about 30 miles per hour), and of course a Supercharging station.

Unless you have time to kill, Supercharging is the only electric-car option that even comes close to pulling into a gas station and getting 300 more miles of range in five minutes of fueling - a familiar undertaking for anyone driving a conventional car.

Tesla has invested hundreds of millions in the Supercharger network, which is most fully built up in the US, where Tesla says it's possible to go almost anywhere and not be at a loss of fast charging. Europe is also expanding, as is China.

But Tesla had to do this, correctly recognizing that without fast charging, electric cars aren't competitive with gas-powered vehicles. No one has the hours to waste on charging.

This is a big deal because no other car company has to spend millions on fueling infrastructure - GM doesn't do gas stations.

It's a considerable cost, but it gives Tesla a huge leg up, sort of a like an embedded Starbucks for electricity. So even though it detracts from Tesla's bottom line, it adds an enormous amount to the ownership experience.