Reason(s) for 'always-on' regenerative braking on hybrids?

[Tipjr]

I've owned a Toyota Prius with a separate "B" gear to enable or disable regenerative braking at will on the fly with the flick of a finger. It's right there at the shifter, no digging around in menus. The 2025 Lexus UX 300h has also reintroduced the "B" gear this year after it being absent. It's great for braking when needed and also having the relaxing option of coasting when it's not needed. It may be worth noting both those models are FWD vehicles. All the other Toyota and Lexus hybrids I've looked into have 'always-on' regenerative braking, and tend to be offered as AWD. Is there a mechanical correlation then? I'm trying to figure out why a manufacturer would offer a customer less control over their driving experience rather than more control. I've also wondered if 'always-on' regenerative braking may be a government requirement imposed upon manufacturers in order for them to be able to post the most favorable fuel economy numbers....I love regenerative braking when I'm allowed to control it's use, but really dislike it on all the time. I've asked around and others (particularly non-hybrid drivers) have agreed having it on all the time feels "weird" and "uncomfortable".

Edited August 27 by Tipjr

[RX400h]

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There are a few factors to consider: (source: CoPilot AI)

1. Mechanical Design: In AWD hybrids, the regenerative braking system often involves both the front and rear electric motors. This setup can make it more complex to offer a manual control like the “B” gear, as the system needs to manage regenerative braking across multiple axles. In contrast, FWD hybrids typically have a simpler setup with regenerative braking primarily managed by the front wheels, making it easier to implement manual control.

2. Energy Efficiency: Always-on regenerative braking can maximize energy recovery, which is crucial for improving overall fuel efficiency and extending the range of hybrid and electric vehicles. This might be why manufacturers lean towards always-on systems, especially in AWD models where the additional regenerative braking from the rear wheels can further enhance energy recovery.

3. Regulatory Requirements: While there isn’t a specific government mandate requiring always-on regenerative braking, manufacturers are incentivized to achieve the best possible fuel economy ratings. Always-on regenerative braking helps in this regard by consistently capturing energy that would otherwise be lost.

4. User Experience: Manufacturers often design systems based on the average user’s preferences and driving habits. While some drivers, like you, prefer having control over regenerative braking, others might find it more convenient to have the system manage it automatically. This can lead to a smoother and more predictable driving experience for the majority of users.

It’s understandable that always-on regenerative braking can feel “weird” or “uncomfortable” to some drivers, especially those who are used to traditional braking systems. Your feedback is valuable, and it’s possible that future models might offer more customizable options to cater to different driving preferences.

Our RX400h acts similarly to pure-ICE vehicles, so there is no need to become accustomed to switching vehicles on a consistent basis.

I have read that some owner of EVs become so accustomed to regeneration that results in their not needing to apply their brakes, that when they drive a non-EV, they sometimes get nervous about not having the same regenerative effect.