One of the main reasons Tesla (NASDAQ:TSLA) shares jumped earlier this month after the company reported fourth-quarter results was the electric-car maker's guidance for vehicle deliveries during 2016. With the carmaker expecting deliveries to grow from about 50,600 in 2015 to 80,000 to 90,000 vehicles in 2016, the guidance may have boosted confidence in the company's ability to execute, going forward.

But is this guidance realistic? After all, Tesla's actual deliveries by year-end have fallen short of initial guidance for two years in a row.

Model X Family Car

Model X.

Looking back
How did Tesla's guidance pan out compared to actual results in previous years? It's been a combination of hits and misses in the previous three years -- but the misses came in the latter two.

Year

Initial Guidance

Actual Vehicle Deliveries

2013

20,000

22,442

2014

35,000

31,655

2015

55,000

50,557

In 2013, Tesla was ramping production of Model S. The production ramp exceeded management's expectations, helping the company outperform its initial expectations.

In the following year, longer-than-expected factory shutdowns for tooling installation, artificially high demand in China from scalpers who didn't follow through with orders, and worse-than-expected year-end deliveries from weather hurdles and customer vacations, all played a role in the company's worse-than-expected annual deliveries. For 2015, a delayed Model X launch was the primary reason for Tesla's lower-than-expected deliveries.

With such a spotty track record on following through initial guidance, why should investors believe the company can deliver on its expectations for such considerable growth in 2016?

Is Tesla's guidance realistic?
The company's outlook for 80,000 to 90,000 Model S and X deliveries in 2016 is definitely worth taking a closer look. After all, the midpoint of this guidance -- 85,000 deliveries -- implies that growth in year-over-year deliveries will accelerate compared to growth achieved in 2015. If Tesla were to deliver this many vehicles, unit sales would increase by a whopping 68% compared to 2015, easily trumping Tesla's 60% year-over-year growth in vehicle sales in 2015.

Despite Tesla's spotty track record, and despite the fact that the electric-car maker's guidance is now as ambitious as ever, there are several reasons to believe management's expectations are achievable.

1. Tesla is now guiding with a range. Initial guidance for deliveries before this year has always been provided in the form of a specific target. It's likely the company wanted to provide a range this year to give more wiggle room for worst- and best-case scenarios.

2. Demand isn't a problem. Deliveries during the year won't require any changes to demand for Tesla's vehicles. Demand continues not to be a problem. Despite no paid advertising and still not showing Model X in stores -- not even in picture form -- order growth for Model S continues to rise, and Model X orders are up 75% compared to the year-ago period.

3. Tesla's production ramp has been underestimated before. Tesla's 2013 for Model S somewhat mirrors what 2016 represents for Tesla's Model X. Both Tesla and investors underestimated the company's ability to ramp production of its Model S sedan in 2015 -- and the same could happen this year.

Model X Production

Model X production. Image source: Tesla Motors.

4. Management has said it's factoring in more conservatism.
"Winning needs to feel like winning," Tesla CEO Elon Musk said during the company's second-quarter conference call last year (via a Reuters transcript) when he was explaining that Tesla would be more careful about guidance in 2016.

With these items in mind, I'm betting Tesla delivers 80,000 or more vehicles during 2016, driven primarily by a rapid ramp-up of Model X production.

Daniel Sparks owns shares of Tesla Motors. The Motley Fool owns shares of and recommends Tesla Motors. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.