US stock analysts are being wary about the prospects for Tesla’s recently unveiled prime mover.

The company unveiled its new all-electric semi trucks recently to much fanfare last week but some analysts are advising caution when it comes to the future prospects for the new big electric truck.

Tesla says its trucks will be ultra fast, super smooth, and have a surprisingly long range. They’re also claimed they will be priced competitively at around $US200,000 line ball with their gas-powered equivalents.

Everything seems to be aligning for them to be a big hit, but as US media outlet CNBC notes, the long-haul trucking industry will probably be very slow to adapt.

Another analyst, Barclay’s Michael Cohen said in a piece he issued said mounting regulatory pressure and future policy changes may push freight carriers to adopt lower-emission power trains in their vehicles,.

However Tesla’s semitrailer might be aimed at the segment of the market that will likely be the slowest to transition to electric drivetrains.

“Constraints on price, range and payload capacity suggest the long-haul market may be the last to embrace electric trucks, after urban freight and other shorter-range, lighter-duty vehicle markets,” said Cohen.

While Cohen remains bullish on EV adoption in the trucking industry — especially considering regulatory changes coming down the pike — he still believes “displacing oil in long-haul trucking has the most daunting cost and technological challenges of all segments.” In other words, lighter trucks may have been a smarter choice for Tesla to attack first.

Other critics also note that Tesla hasn’t disclosed the weight of the battery on the truck, which could cut into its payload considerably.

The four-motor truck was announced with a 800km range and some self-driving capabilities. At the launch Elon Musk did not provide a price for the electric prime mover. However late last week the company revealed the regular versions of the 500km and the 800km trucks shoulc cost between $US150,000 and $US180,000 each.

They also revealed that there will also be a “Founders Series” which will cost $US200,000 per truck. Tesla says the prices are “expected” leaving the company some wiggle room on the final pricing.

If those prices and specs stick then Tesla has a potentially disruptive offering with Semi. Most long-haul diesel trucks are priced around a similar level in the US and cost tens of thousands of dollars to operate each year. Tesla claims its all-electric Semi will provide more than $200,000 in fuel savings alone over the lifespan of the truck.

Companies with fleets of trucks are already showing interest. Large transport carriers like JB Hunt Transport Services, NFI Industries, and Bison Transport have all reserved trucks  as have retailers like Walmart, Loblaw, and Meijer. Tesla says the first Semis are expected in 2019.