Tesla Inc. Chief Executive Officer Elon Musk has said his company was building advantages in the ability to make electric cars cheaply and efficiently. Those claims keep looking more questionable.

The latest knock against Tesla’s production credentials comes from Munro & Associates, a small Detroit-area firm that disassembles new cars and analyzes them down to the nuts and bolts. Founder Sandy Munro has picked apart a Model 3 sedan and praises its battery pack and electronics but pans much of the rest of the vehicle as costly, heavy and poorly built.

For Tesla, developing the ability to mass-manufacture cars is key to its viability. Musk, who predicted programmable robots would give his electric-car maker a leg up over the rest of the auto industry, has instead confronted repeated delays and steep losses. If Munro is right, Musk may have a more lasting problem on his hands: His first car for the masses could be weightier and more expensive to build than competing models that are on the way.

“Mechanically, I don’t have much good to say,” Munro said last week on “Autoline After Hours,” a Metro Detroit local television show. “If it would have come out even decent, they’d have mopped the floor with everybody. But they didn’t.”

A Tesla spokeswoman said the company has been refining its Model 3 manufacturing process since starting production last year and that the standard deviation of all gaps and offsets across the car has improved on average by almost 40 percent, with particular gap improvements visible in the area of the trunk, rear lamps and rear quarter panel.

NO 'MICKEY MOUSE'  

The Model 3 has great battery design and industry-leading electronics, according to Munro, who will elaborate on his findings at an Automotive Press Association briefing on Wednesday. Its packs are better in terms of power and efficiency than those built by Samsung SDI Co. or LG Chem Ltd., he said. The two companies supply the batteries for BMW AG’s i3 and General Motor Co.’s Chevrolet Bolt electric cars.

The circuit boards in Tesla’s newest sedan also are on par in terms of complexity with those used in cell phones, high-end computers or military fighter jets, Munro said. Other carmakers should take notice.

“This is not some Mickey Mouse outfit that you can just dismiss,” he said. “Ignore Tesla’s electronics, and you’re in peril.”

MUSK'S MISTAKE 

The challenge for Tesla will be figuring out how to efficiently build the car at its assembly plant that Musk himself has said employed too much automation. In an interview earlier this month with CBS This Morning, the CEO said that excessive use of robots has been one of the factors holding the company back from making more Model 3s.

Musk may have to follow his hunch and hire more humans. Munro said this wouldn’t be unprecedented. GM once called him in to inspect the robots the company was trying to use many years ago, before its 2009 bankruptcy.

The cars weren’t designed to be built with heavy use of robots, and the automaker ended up taking them out of the plant, he said.

BODY ISSUES

Munro also had some harsh words about the Model 3’s design, which he said appeared to be done by someone who lacked experience in body engineering. The car has eight or 10 panels welded together that all create weight without adding strength. For a vehicle of its size, the Model 3 is the heaviest and most expensive to build, he said.

The car Munro & Associates purchased and analyzed had inconsistent gaps between body panels, which Munro said may be an indication that people on the assembly line weren’t properly trained.

The Tesla spokeswoman said body production on newer models is competitive with German luxury cars. “Today, Model 3 panel gaps are competitive with Audi, BMW, and Mercedes models, but in the spirit of relentless improvement, we are working to make them even tighter,” she said in an email.

The silver lining for Tesla is that the company’s biggest weakness might be fixable: there are plenty of experts available to get Tesla’s factory humming.

“They have a hard time with what I would classify as the dinosaur technologies, the mechanical stuff,” Munro said. “There are hundreds of us in the field that could help them fix that. I hope they pick one.”