Make REX engine available on wheels

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Srivenkat

Well-known member
Joined
Apr 21, 2018
Messages
88
Since the REX engine is a component of a "serial" hybrid, making the REX engine available as an accessory would be beneficial for the following reasons:

1. Environmentally beneficial:
(a) Many inbuilt-REX purchasers may use it only occassionally, if at all. So, lugging around ~300 lbs at all other times isn't good for the environment, along with construction costs and minimum maintenance required for the REX engine.
(b) Many current ICE owners who balk at the idea of EVs might reconsider if they are assured that an ICE-on-wheels can be purchased or rented and added as an accessory, as their range needs change.

2. This would go well with the modular concept that has been used with the i3 design. Along with battery upgrades, one won't be boxed in with the initial range of the car.

3. ICE-on-wheels can be larger than the current REX engine, with a bigger gas tank so that highway speeds can be sustained for a longer range, regardless of battery SOC.

4. This will obviate the need to rent a whole car, which again would be better for the environment.

5. Well-maintained ICE-on-wheels can be made available at BMW dealerships, instead of , or in addition to whole cars.

6. ICE-on-wheels can also made to double as a generator for the house.

I am sure BMW is capable of making the ICE-on-wheels asesthetically pleasing.
 
A detachable range extender would be a nice EV feature that would enable long-distance driving but would not encounter the range extender weight penalty on most days. But when thinking about the practicalities, it becomes obvious that designing a detachable range extender would be a significant engineering challenge. The i3's REx weighs at least 300 lb. when everything is included. Making such a heavy item manageable at an i3 owner's home would be daunting. The i3's suspension would need to be work well with and without this added weight which would presumably be concentrated at the extreme end of the car. Modular designs frequently aren't as space-efficient as integrated designs which is especially critical with a small car like the i3.

A small range extender trailer might be a better approach.
 
Thanks for the thoughts, Art. I agree a trailer might be a better approach. As for strengthening the rear suspension, that would also come with the added benefit of being able to handle light loads such as a multi-bicycle rack, etc.
 
One other thought is that, BMW could at least make the REX engine a module that could be added at a later point by the dealer. This will go a long way in satisfying certain kinds of range anxieties where current commutes might be well satisfied by the BEV range, but a change of job, etc., call for the added REX range/flexibility. Will add this as a separate suggestion.
 
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