On Tuesday, Tesla CEO Elon Musk took to Twitter to respond to queries from the company’s fans and followers. In his series of replies, Musk promised new software-based functionality and repeated a vague promise that he made back in April: that after a Model Y SUV, Tesla would introduce a pickup truck to compete with Ford’s F series.

The pickup truck promise was made earlier this year at the same time that Musk announced a semi from his electric vehicle company. Specifically, the CEO said that the semi announcement would happen in September 2017, and he promised a pickup truck announcement some time between October 2018 and April 2019. But the whole timeline was thrown off by the Model 3 passenger car, which was supposed to hit mass production in July 2017. It struggled to get off the ground due to manufacturing bottlenecks, and the semi announcement was delayed to November 2017.

Musk didn’t give a revised date for when Tesla would officially announce a pickup in his Tuesday tweet, but he said that the truck would start rolling off Tesla production lines some time after the Model Y.

“I promise that we will make a pickup truck right after Model Y,” Musk tweeted. “Have had the core design/engineering elements in my mind for almost 5 years. Am dying to build it.”

The Model Y is an unannounced future Tesla vehicle, likely a compact SUV. The CEO discussed it briefly in a May financial call in which he said the Model Y would come “sometime in 2020 or, aspirationally, sometime in 2019.”

In response to a question yesterday about whether the Tesla pickup would be comparable to the Ford F150, Musk tweeted: “Similar total size. Maybe slightly bigger to account for a really gamechanging (I think) feature I’d like to add.” The CEO didn’t elaborate on what the feature would be.

The CEO also gave a high-level view of the energy industry’s continued transition to renewable energy sources, saying, “Sustainable energy production with solar and batteries will grow much faster than auto on a percentage basis. That will be a big focus next year, with primary remaining Model 3 ramp.”

For the most part, however, Musk promised that Tesla would be releasing smaller software-based improvements, like rain-sensing windshield wipers (a function that has been on the back burner for some time), better maps and navigation, and browser updates.

He even responded to one request for an in-car “Disco Mode,” saying the idea “sounds like good, cheesy fun :).”