The head of the nation's largest auto retailer even joked that Tesla was "either one of the great Ponzi schemes of all time or it's gonna work out."
Jackson's comments follow a recent
This is despite the fact that Tesla produced only a fraction of the 10 million cars GM made last year. Tesla also has only had two profitable quarters in its history as a public company, while GM earned more than $9 billion last year alone.
Jackson said Tesla's valuation fails to recognize that the company can't seem to turn a profit regularly. Overall, he said he isn't impressed by Elon Musk's electric car company.
"What would impress me about Tesla?" Jackson said, speaking at the NADA/J.D. Power Automotive Forum ahead of the New York Auto Show. "Selling vehicles at a profit would be very impressive. Giving away vehicles at below what it costs you to make them is not very exciting."
And Jackson doesn't see a profit coming for Tesla anytime soon. If Tesla can't make money in the $100,000 price bracket, he's skeptical that moving down to the $35,000 price range with the Model 3 will make the company money.
Tesla is set to begin production on its more affordable Model 3 sedan this year.
Jackson also is doubtful of the consumer pull of fuel-efficient electric cars.
Consumers keep trending toward less fuel-efficient trucks and SUVs, implying that environmental factors aren't high on their list of purchasing priorities, he said. The proliferation of hydraulic fracking, he says, means that affordable gasoline is here to stay.
"It is underappreciated that gasoline is affordable in the U.S. as far as the eye can see," he said, saying that should factor into Tesla's valuation.
A severe gas spike, Jackson added, just isn't on the horizon. Through fracking, the U.S. has discovered "several Saudi Arabias" worth of oil to hold us over from other countries cutting output.
"If OPEC was ever to try a boycott again, we could simply look at them and say,
Tesla wasn't immediately available for comment.