I woke up April 1 and noticed an email from Tesla on my phone: What! Free self-driving mode on my Model Y for the entire month?

For the past four years, I'd used standard autopilot on every out-of-town trip. It has made longer drives so much less taxing. So how much better would full self-driving be? Could it really be worth the then $12,000 price tag?

Since it was April Fool's Day, I guessed Elon Musk was playing a joke on tightwad Tesla drivers. I'd hop in the car, fire up the feature and trigger a video on the center screen of Musk wagging his finger and laughing at me.

But no, he was good to his word. And now I'm no longer curious: It's cool but still a work in progress.

Key capabilities in Tesla's full self-driving mode

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A few numbers and initial thoughts about Tesla's full-self driving mode

◾ 10%: That's about how frequently I kept self-driving mode on when driving around town. It felt more as if I were playing a game of chicken with parked or oncoming cars than getting a helping hand. I probably wouldn't have kept it on that often if I weren't testing it out. Details below.

◾ 80%: About how often I used it on roads where speeds were consistently over 50 mph. That kept my stress levels in check until we neared cities where I trusted my fellow drivers even less than Tesla's system. Details below

◾ 100% amazing: The first moments of the experience never got old. After setting my destination and flicking a stalk on the steering column, the amusement-park ride started: The wheel turned in my hands and the car rolled forward. On went the turn signal. We glided to a stop at the intersection, paused and paused for traffic, and turned up the hill. Even on the unmarked road, the Tesla hung to the right side of the road – easily avoiding the parked cars.

Tesla's earnings and autopilot take turns for the worse

But even as Tesla was trying to tempt us owners to pay up for the full self-driving mode in April, the news hasn't been great for the feature or the company's financial results.

Just a few days ago, the National Highway Transportation Safety Administration said it's investigating an Autopilotfix Tesla made in December to the more than 2 million Teslas on the road. The over-the-air update sought to solve issues that led to nearly 1,000 incidents involving the three levels of the driver assist. Since the update, 20 more incidents have been reported.

Types of Tesla crashes when Autosteer was engaged

The most concerning accidents appear to stem from 211 drivers who weren't monitoring the system. The full self-driving system is clearly labeled "supervised," but it's pretty easy to get complacent. NHTSA wants assurances that drivers will remain attentive to potential dangers.

Part of that fix may already be made. On my final free-trial day, I received more frequent messages to keep my hands on the wheel. There's also a tiny camera in the rearview mirror that keeps tabs on you. If it decides you're checking your phone or not watching the road, you'll also get a blue-screen reminder.

Warnings drivers receive from the Autosteer technology

The renewed concerns about the Autopilot system came on the heals of Tesla's quarterly net profit tumbling 55% to $1.3 billion as revenue fell 9% from the first quarter of 2023. Tesla also trimmed prices of three of its models in April to goose demand. It also has cut the price of the full self-driving feature (something Musk suggested wouldn't happen).

That leaves one last number from my experience:

◾ 33% off: I still don't see spending $8,000 – down from $12,000 – for this feature. Maybe I'd pay the $99 a month for a road trip, but I'm not tempted to buy it because all I really need are the "Autopilot" driver-assist features that come standard. I wonder how many Uber rides $8,000 could buy?

News hasn't been all bad for the Autopilot system, though. In recent days, Tesla reached a deal with China to have full self-driving cars on its roads, according to Reuters. Since the deal, Tesla's stock price hit its highest levels since early March, according to Yahoo! Finance.

How Tesla's autopilot worked (or didn't) in local driving

If you've been wondering what's up with Tesla drivers in recent weeks, blame it on Autopilot. Going forward, it's probably on us.

Maybe the car in front of you seemed sluggish as it meandered through the neighborhood – seeming to sense every car parked along the unmarked street. Perhaps it actually stopped at a stop sign, sat there for a few beats, rolled up a few feet and then accelerated into the intersection.

Moments like those tested my patience and the drivers behind me. I felt as if I had to shut it down at times to be a good neighbor.

Note to self: You might be a little impatient. After editing these videos, the pauses at stop signs really weren't that long. That said, in the video above you might sense my alarm as two cars were fast approaching and my car still seemed to be assessing the situation.

A close call in full self-driving mode

Adam Neal, a USA TODAY Network editor in Florida, had a much closer call on his way to work in Vero Beach.

Neal tried out the full self-driving mode on the first day it was available. And with video rolling, Neal slammed on his brakes to keep his Model 3 from crashing into a truck.

Final impressions of Tesla enhanced autopilot

A few random thoughts:

◾ Right turns on red: Sure, the right turn on red has been around for decades. I just didn't expect the Tesla's sensors would have enough range to determine it was safe to make such a turn. I'm just sitting at a red light with the turn signal blinking and then all of a sudden we're going. Pretty cool and no close calls.

◾ Keeping pace – not the peace – on the highway: Without full self-driving, I keep pace with faster drivers in the left lane and slide to the right when real lawbreakers want to get through. Not my Tesla. Those back sensors don't seem to care if a big, pickup truck is inches from the bumper. It's all about maintaining your maximum speed, considering it also seems to sense when cars are moving faster in other lanes. On goes the turn signal, and seconds later you're in the next lane over. That may let your friend in the pickup offer you an inappropriate salute.

◾ You're leaving the highway too FAST! Exits bounded by solid white lines are probably the easiest part of the road for the Tesla to navigate. It's so easy that one moment you're flying along a road at high speed and the next you're barreling down the exit at whatever maximum speed you might have set. It can feel a bit like a runaway train, which your passenger(s) might enthusiastically point out.

So long to Tesla's full self-driving mode.

You made driving in April both a bit easier and little scarier, but now it's time to say goodbye. Well, once Tesla actually turns off. I didn't mind firing up one last time on May 1.