Boltar ) gurgled happily, sounding much like they
were saying :

It's flat out at 15mph, so slower than my mountain bike, and does
about 200mpg.

Why not dump the petrol engine if thats that feeble and install an
electric motor which would have the same performance (albeit with
reduced range)? That way no tax & insurance required.

If I wanted to do that, I'd buy a half-decent bicycle. No, wait, I've got
one as well.

I think you may have missed the point of it. It's frivolously
hardlymobile...