If Tesla's safety record applied globally, the company said it would result in 900,000 fewer vehicle fatalities every year and that those driving Teslas equipped with autopilot hardware "are 3.7 times less likely to be involved in a fatal accident".
Musk said in the memo that Tesla still plans to hire more people to help it ramp up its Model 3 production.
Last week, Tesla said Doug Field, senior vice president of engineering, was taking time off to recharge.
After a rough start to the week - Tesla shares closed down 3 per cent Monday after Chief Executive Officer Elon Musk announced a "thorough reorganization" - Jonas' latest call is further weighing on the stock Tuesday, with shares down as much as 3.9 per cent in morning trading.
And despite the company's claims that it would not need to raise money, Jonas raised his estimate for Tesla's capital raising to US$3 billion from previous US$2.5 billion, which he continues to expect in the third quarter of this year.
However, representatives of the company repeatedly warned the owners of electric Tesla, that when using the autopilot, they should still be careful and watch the road.
"It certainly needs to be better and we work to improve it every day, but ideal is the enemy of good", Musk tweeted. The CEO said Tesla vehicles were the safest on the road, four times better than average.
Despite the rocky relationship between Tesla and the NTSB, agency spokesperson Keith Holloway said he's still uncertain as to whether the agency will open an investigation into the accident.
Drive told investigators she had the vehicle's semi-autonomous Autopilot mode engaged when she slammed into the back of the truck. Police said the Tesla driver, who was reportedly looking at her phone before the crash, was taken to hospital with a broken ankle, while the truck driver suffered whiplash.
"Tesla has not yet received any data from the auto and thus does not know the facts of what occurred, including whether Autopilot was engaged", a Tesla spokesperson said in a statement on Sunday.
Tesla has been struggling to find solutions to manufacturing bottlenecks on the new assembly line that produces the Model 3, a sedan intended for volume production.
The National Transportation Safety Board said last week it was investigating a Tesla accident in Fort Lauderdale, Florida, on 8 May that killed two teenagers and injured another - the agency's fourth active probe into Tesla crashes.