BMW i3 Forum

My recent guess is probably incorrect. The circular part is a flange cover and closure ring to access the fuel pump:



There does not appear to be enough clearance between it and the fuel pump to add a half gallon sized plug directly to it, but does provide a large enough opening for BMW to slip in another means of displacing volume, in the same way folks drop a brick in the toilet tank to reduce the volume of each flush.

We decided to buy the car, a Giga REx with all options except 20" wheels. Picked it up yesterday. We'll continue to try to sort out the tank issue and if we can get the 2.4 gallon capacity somehow, great. If not, we'll live with it. This is going to be a great car even if the fuel tank has been screwed with.

Will report back when I hear from my friend in Belgium. Since we decided to go ahead with the purchase, i told him that his visit to the dealer there wasn't urgent, but that I would still appreciate hearing the result of his inquiry in the next couple days or so.

Thanks, Tom, for the excellent further info.

I enjoyed this older post. Back then, so little information about this vehicle was available to us.
Coding transformed this little jewel in a weekend warrior.. lol