Let me start this blog off by saying I would never, ever, bet against Elon Musk in the long run. The guy is clearly a certifiable genius. But, like a lot of hyper-intelligent people, he’s definitely “out there.” So I find myself wondering from time to time if the guy is flake, or if he’s finally taken on a challenge he can’t overcome.

And then he launches his personal roadster into orbit around the sun or something, and I go right back to believing that Musk is simply operating on a level that someone like me will never be able to fully appreciate or understand.

In fact, when I look at the vast array of technologies Musk is currently working on — the hyperloop, space-based internet for the entire planet, solar-panel roof tiles and residential battery packs to take homes and commercial buildings off the electric grid and them completely energy self-dependent — my sense is that when the historians finally getting around to writing about these decidedly crazy times we’re living through, Musk will probably be cited as the inventor/innovator/genius of the time who, more than anyone else, transformed the world of tomorrow into a better, cleaner, more modern society.

All that said, however, Tesla clearly has a problem on its hands with its again-delayed Semi long-range electric truck, which has once again had its launch date pushed back.

When the truck was unveiled to much fanfare in 2017 (I was there for that interesting event), Musk said the Semi would enter production sometime in 2019. Now, the somewhat fuzzy timeline for the truck’s launch is sometime next year.

For some context, consider that elsewhere, electric truck debuts are happening left and right. As I write this, on August 12, Volvo President Peter Voorhoeve is appearing on CNN, BBC, and other news outlets touting the coast-to-coast rollout of the new VNR electric Class 8 trucks. And that is to say nothing of Daimler Trucks North America, which has had similar successes rolling out its eCascadia Class 8 models. Peterbilt’s Model 579e, which is available for order, was in the nation’s capital last week.

So, what’s going on with the Tesla Semi? Why all the delays?

From the outside looking in, I’ve got a couple of educated guesses.

The first likelihood, in my opinion, is that Tesla over-promised on the Semi’s projected 500-mile daily range on a single battery charge. Optimism and an unshakable faith in the ability of technology to overcome problems is a cornerstone both for Musk and the company he founded. I’m guessing the company was banking on some major battery technology breakthroughs in terms of energy density and capacity that simply haven’t happened yet. And who knows? Maybe the battery wizards are close to that elusive breakthrough, and the extra time will be all they need to make the Semi live up to Musk’s initial performance promises.

Another possibility that’s occurred to me is durability issues with the Semi. Is this truck, despite all its vaunted new electric technology, tough enough to handle daily life in brutal Class 8 long-haul applications?

At the Semi launch in Hawthorne, California, back in the Fall of 2017, trucking journalists were given a rather brief, close-up look at the Semi truck prototypes. I remember being struck by the powertrain arrangement on the vehicle. The truck was (and presumably still is) powered by three Tesla Type S automotive electric motors that were married together and mounted laterally on the truck’s frame rails behind the cab.

And that struck me as odd.

Trucks aren’t simply scaled-up cars, as more than one manufacturer has discovered to its chagrin over the past century. And I remember wondering if those automotive motors would be able to handle the shock, vibration, dirt, dust, grime and water associated with Class 8 trucking. It just seemed to me that a single, larger, purpose-built, truck-optimized electric motor would be a better choice. And that such a choice would be obvious to a truck OEM with decades of experience working with fleets.

Neither of these two scenarios are fatal, of course. As I said from the outset, I wouldn’t advise betting against Musk or his team at Tesla. But for now, we’ll have to wait another year or so before we learn when and if the Semi will hit the road.