Mercedes-Benz has walked back an earlier plan to allow owners of certain electric vehicles to unlock maximum performance via subscription only.

The automaker on Wednesday said its Acceleration Increase feature for the EQE 350, EQE SUV 350, EQS 450, and EQS SUV 450 will now be offered via subscription or a one-time purchase.

The on-demand feature can be purchased online at the Mercedes Me Connect Store and installed via an over-the-air update, meaning a visit to a dealership isn't required.

For the EQE 350 and EQE SUV 350, Acceleration Increase boosts output from 288 to 348 hp, which results in the 0-60 mph time dropping by 0.9 second to 5.1 seconds for the EQE 350, and by one second to 5.2 seconds for the EQE 350 SUV.

For the EQS 450 and EQS SUV 450, the feature boosts output from 355 to 435 hp, and drops the 0-60 mph time by 0.8 second to 4.5 seconds for the EQS 450, and by 0.9 second to 4.9 seconds for the EQS SUV 450.

Acceleration Increase at a glance

Acceleration Increase at a glance

Buyers can choose between monthly or annual subscriptions, or make a one-time purchase that retains the feature for the life of the vehicle. The monthly subscription costs $60 for the EQE models and $90 for the EQS models. The annual subscription bumps the costs to $600 and $900, respectively. The one-time purchase cost is $1,950 for the EQE models and $2,950 for the EQS models.

Mercedes originally planned to charge a $1,200 annual subscription across all models, when Acceleration Increase was first announced last fall.

This isn't the first time Mercedes has offered an on-demand feature via subscription. In some markets, the automaker charges an annual subscription to unlock the more advanced rear-wheel-steering system on the EQS, a feature that for now is standard in the U.S. The more advanced system can tilt the rear wheels up to 10 degrees, versus the standard system that tilts them only 4.5 degrees.

The automaker offers many more on-demand features via the Mercedes Me Connect Store, enabling owners to upgrade their vehicles at any time. These include nanny systems for beginner drivers and valets, the AMG Track Pace performance data recorder, remote engine start, expanded navigation features, and more.

Mercedes said more on-demand features are coming, though the automaker said certain hardwired, standard features like heated seats won't be offered in this fashion.