Tesla Model Y - 2 Year Review, Battery Degradation

Two years ago, we drove home in a new Model Y. It's been a great car for us. My wife and I both prefer to drive this vehicle over our 2nd car (2018 Model 3), so the Model 3 doesn't hasn't had much time out of the garage for the last 2 years.

As our Model Y celebrates its 2nd birthday, it has just over 17,000 miles on the odometer.

Let's look at where we've driven, the software and full self-driving (supervised) updates we've received, and the degradation of our pack.

Trip Check

Bend

In March, we took a 350-mile round-trip to Bend, Oregon to visit some old friends and do a little spring skiing. We were able to make the drive from Portland to Bend without stopping to charge. There are two Tesla charging locations in Bend. We stopped at the one closest to our friend's house to grab a few kWh before unloading. This was the first time that I've seen our car charging at more than 1000 miles per hour. This was impressive.

We charged to just over 50% and then headed to our friend's place. When we arrived, he was excited to see us, as well as to see the car. He had a NEMA 14-50 outlet installed in his garage for his future EV and wanted to know if it worked. I had my mobile charger (don't leave home without it) and the required adapter. We plugged it in and it worked fine.

The trip was great fun, and we had no issues getting home.

Corvalis

We've made multiple round-trip drives to Corvallis. The nice thing about this 160-mile drive is that we don't need to stop to charge at all. There are multiple places we could charge (Wilsonville, Woodburn, Salem, and soon Albany), but nothing's as convenient (or affordable) as charging up at home. 

Driving Stats

This year, we put over 8,000 miles on the odometer. In the first year, we put just under 9,000 miles on the road. 

We Supercharged 4 times this year, compared to just charging 1 time in our first year. This is a little ironic since we drove more in the first year.

Our longest non-stop leg of any drive was just over 100 miles from Mill City, OR (where we stopped for lunch) to Bend. This mountainous drive used 46% of our battery capacity. This is also when we hit our highest elevation of 4,807 feet on the Santiam Highway before passing through Sisters, Oregon. 

Tires

Our OEM all-season tires (Continental ProContact RX 255/45 R19 104W XL), which came on our Y when we picked it up, now have about 9,500 miles on them. Our winter tires (Michelin X-Ice Snow 255 /45 R19 104H XL BSW) have about 7,500 miles on them. 

The all-seasons are averaging 253 Wh/Mile (85% efficiency), while the winter tires are at 278 Wh/Mile (77% efficiency).

Accessories

In the first year, we installed a roof rack system on our Y, and it didn't significantly impact the range.

Firmware Updates and FSD 

We started our second year of ownership on software version 2024.21.5 and (21 updates later) we finished it on 2025.26.4.

These 21 updates improved the backup camera view, improved security, added a new owner's guide, better audio controls, forward collision warning improvements, made use of the mmWave radar for child left alone detection (more on this coming soon), and many more items.

The latest new feature of note is the addition of Grok in the vehicle. It will be interesting to see what this evolves into.

FSD (Supervised)

Many of these 21 updates included new FSD versions too. We're currently on FSD v13.2.9. This is the best version of FSD yet; autonomy is going to happen.

Battery Degradation

Below is an interesting Model 3 and Y battery degradation chart with several model years on it. As you can see, the 2023 and 2024 Model Ys have the lowest degradation rate. That's good news for us.

Now let's compare this to my measured results. 

As you can see, we have about 7% degradation here at the end of year two. EV batteries degrade faster in the first 2 to 3 years due to an initial chemical stabilization reaction. During early cycles, a solid electrolyte interphase (SEI) layer forms on the anode. This consumes some of the lithium in the battery and reduces capacity. When the SEI layer stabilizes, degradation slows. So, perhaps next year's degradation will be lower.

This degradation brings our EPA-rated range down from 330 miles to 307 miles. Still more than enough for our needs, even fully loaded in winter. The usable battery capacity is estimated at 74.5 kWh, down from its initial 80.2 kWh. This is one of the reasons that we purchased a long-range EV. Some degradation is normal, and if we bought a vehicle that could just barely do what we needed, and then the capacity reduced, we'd be unhappy with the vehicle. 

Referrals 

If you're interested in a Model Y (or any other Tesla), you can use my referral code and we'll both get perks (https://ts.la/patrick7819).

If you want to track your Tesla's battery degradation, highest elevation, or longest road trip (mine's easy to beat), you can use my TeslaFi referral to get all kinds of cool stats. Using a referral code gets you an extra month free, and I get one too.