Bill Gates co-founded America’s most valuable company and has become one of the world’s leading philanthropists. But Tesla CEO Elon Musk finds him “underwhelming.” In a tweet Tuesday morning, Musk dissed Gates after the Microsoft founder mentioned in a recent interview that he had bought an electric Porsche Taycan, rather than a Tesla. In the interview with Marques Brownlee on YouTube, Gates offered a great deal of praise for electric vehicles and for Tesla\n \n (TSLA). “Passenger cars is actually one of the most hopeful [sectors]” when it comes to making the changes necessary to reduce greenhouse gases and battle climate change,” he said. “Certainly Tesla, if you had to name one company that helped drive that, it’s them,” he said. And he said he’s enjoying his new electric Porsche. “I’ve got to say – it’s a premium priced car – it is very, very cool. That’s my first electric car and I’m enjoying it a lot,” he said. Gates said he believes the premium in pricing between gasoline powered vehicles and electric vehicles will disappear in the next 10 years, and that when it does, not much will stop people from buying electric vehicles. But he said one issue stopping some buyers from changing to electric is the more limited range for electric vehicles. Even if there is a charging station available, it is more time consuming to recharge an electric vehicle than it is to fill up a gas tank. “The amount of energy going in per minute of filling your gas tank is kind of mind blowing. Gasoline is very dense energy,” he said. Musk did, however, praise Bill Gates’ past chair-jumping abilities.