2026-10-18

Why your Tesla shows less range than the EPA rating

One of the most common questions we get: "The EPA rating says one number, so why does the car show fewer miles on a full charge?" There's a lot of confusing information online about this. One big part of the answer is something most drivers never hear about: the hidden buffer.

What the hidden buffer is

Every Tesla keeps a small part of its battery in reserve. You can't see it on the screen. When the car shows 0% and 0 miles left, the battery isn't actually empty. That reserve is still there.

Why it matters for the EPA number

During the EPA test, a car is driven until it can't keep going, and that run includes the reserve. So the EPA range counts miles that are hidden from the driver.

The range on the car's screen is the battery from 100% down to 0% as displayed, without the reserve. That's one reason the full-charge number looks lower than the EPA rating, even on a car that's healthy.

Drawn to scale. The reserve is roughly 5–7% of the battery; Tesla doesn't publish the exact amount.

Don't drive into the reserve

This doesn't mean you should plan on using those miles. The reserve is there for emergencies. Running a battery all the way down can damage the battery and the car's electrical systems. Treat 0% as empty and charge well before you get there.

Other things that change the number you see

Battery age: like any lithium battery, it loses a little capacity over time.
Weather: cold weather lowers range until the battery warms up.
How you drive: high speeds, climate control and heavy loads all use more energy.

How to check a car's full range yourself

The car doesn't show a full-charge number unless it's charged to 100%. You can estimate it from any charge level: take the range the car shows right now, multiply by 100, and divide by the battery percentage shown.

For example, 240 miles at 80% is 240 × 100 ÷ 80 = 300 miles on a full charge.

Remember that this number won't include the hidden reserve, so it will usually be a bit below the EPA rating.

Comparing model years? See Why a 2024 Model X shows less range than older ones.

Questions about a specific car? Call or text us and we'll walk you through it.

We're a used-Tesla dealer, so we have an interest in the cars we write about. We aim to give you the same straight answer we'd give a friend, downsides included.