Hertz Global is renting a lot of Tesla vehicles. And they're making money, too.

On the company's fourth-quarter earnings call Tuesday, CFO Kenny Cheung said that Tesla (ticker: TSLA) vehicles currently make up roughly 10% of its fleet. Hertz (HTZ) has about 480,000 vehicles, which means their Tesla vehicle count comes out to about 48,000.

In October 2021, Hertz announced it would order 100,000 Tesla vehicles in total. At the current rate, it has been adding approximately 12,000 Tesla vehicles each quarter since the announcement.

Hertz didn't immediately respond to a request for comment about the exact figures.

The penetration of electric vehicles in the rental company's fleet is higher than broader EV penetration in the U.S. About 810,000 all-battery electric cars were sold last year, representing a little less than 6% of all light-vehicle sales. And there are roughly 250 million light vehicles on the road today. One tenth of that number is 25 million, or about 12 times the number of EVs currently in operation.

Those numbers show that EV penetration can still go higher. Hertz thinks so too: CEO Stephen Scherr says 25% of the Hertz fleet will be electric by 2024. Hertz also has plans to buy EVs from General Motors (GM) and Polestar Automotive (PSNY). If the entire stock of cars and trucks on roads were to be at 25% penetration by 2024, it would imply more than 100% average annual growth in EV sales for the coming two years.

Other EV makers would benefit from increased penetration. Ford Motor (F) and GM have announced goals to sell hundreds of thousands of EVs annually in the U.S. by mid-decade.

There is one other thing investors can take from Hertz: The company is making money and hasn't sacrificed earnings or cash flow. In its latest quarter, Hertz reported earnings of 50 cents a share, above Wall Street's expectations for 46 cents a share. Ebitda profit margins came in at 15% and free cash flow adjusted for fleet changes was $424 million in the quarter. Hertz generated about 6% Ebitda margins in 2018 and 2019, before the pandemic forced the company to restructure in 2021.

The outlook for EV sales is solid, at least based on this small example from Hertz.