Microsoft founder, Co-Chairman of the Bill & Melinda Gates Foundation, Bill Gates delivers a speech at the conference of Global Fund to Fight HIV, Tuberculosis and Malaria on Oct 10, 2019, in Lyon, central eastern France. (LUDOVIC MARIN / AFP)

Bill Gates paid Tesla Inc a compliment for coaxing the car industry to go electric. If he was expecting kind words in return from Elon Musk, he apparently shouldn’t have spoken about challenges that still lie ahead -- or about his new Porsche.

Bill Gates called the passenger-car industry “one of the most hopeful” sectors taking action in reducing emissions to slow climate change

Gates, the billionaire co-founder of Microsoft Corp, spoke with a YouTube influencer last week about the challenges of reducing emissions to slow climate change. He called the passenger-car industry “one of the most hopeful” sectors taking action in this regard.

“And certainly Tesla, if you had to name one company that’s helped drive that, it’s them,” Gates told YouTuber Marques Brownlee.

ALSO READ: Tesla new car registrations rise again in China despite slowdown

Tesla CEO Elon Musk speaks during the Tesla China-made Model 3 Delivery Ceremony in Shanghai. (PHOTO / STR / AFP)

Then Gates discussed recently buying a Porsche Taycan. While he called the electric sports car “very, very cool,” he acknowledged its premium price -- the initial Turbo S models start at US$185,000 -- and said consumers still have to overcome anxieties about EVs offering limited range and taking longer to recharge. Gasoline-powered cars travel longer between quick refuels at stations that outnumber charging points.

When a Tesla enthusiast posted about being disappointed in Gates’s decision to buy a Taycan instead of a Tesla and his comments about range anxiety, Musk replied: “My conversations with Gates have been underwhelming tbh.”

A Porsche AG Taycan all-electric luxury automobile sits on stage on the opening day of the IAA Frankfurt Motor Show in Frankfurt, Germany, Sept 10, 2019. (PHOTO / BLOOMBERG)

Musk, 48, is of course no stranger to tweeting dismissively about fellow billionaires. The Tesla chief executive officer questioned Facebook Inc. CEO Mark Zuckerberg’s understanding of artificial intelligence risks in 2017. Last year, he called Jeff Bezos a copycat after the Amazon.com Inc. CEO embarked on an internet-satellite project that could rival one that Musk’s closely held company SpaceX is pursuing.

READ MORE: SpaceX says 'picture perfect' test paves way for human mission

The Tesla CEO’s commentary on Porsche’s Taycan has been mixed. After chiding the sports car brand for using internal combustion engine nomenclature for the high-end version of its debut electric vehicle, he tweeted in September that it “does seem like a good car.”