Ours is a 'supposed' self charging Hybrid but the results are negligible. We relied on petrol and self charge for the first few weeks and averaged about 55mpg, which is what you'd expect from a standard Golf 1.4 petrol engine. On a 100mile run to Worcester we managed to get about 6% charge into the battery which gave us about 1.5 miles worth of electric use.
Now we're charging twice a day, the average mpg is working up - after a total of 3000 miles, it's up to 129mpg which sounds good but doesn't take into account the cost of the charging (about £4.50 per day, but is getting about 60 electric miles out of that, so cheaper than petrol).
We may be at cross purposes here. I assume yours is a plug-in hybrid as opposed to a self-charging hybrid i.e. one that can't be charged from an external supply.
Unless you can keep Plug-in hybrids charged up for most of the time they're not really that efficient, as your own experience seems to have shown.
I've owned both types and am currently in the process of buying another self-charging hybrid. I wouldn't hesitate to go for another plug-in type but my current situation and driving pattern doesn't suit.
