Quote:
Originally Posted by steve-p
The battery charge doesn't just come from regenerative braking - it actually charges the battery anyway using the engine if it's running. For example, when starting from cold with the battery depleted (from the end of the previous journey), the battery is fully charged within about five minutes or so. This doesn't seem particularly efficient, although it's how trains work so maybe it's better than it sounds 
Electric power does make quite a difference to journey MPG. On my commute to work, which is four miles urban and then eight miles fast rural roads, it does 28-30 MPG (adjusted from indicated figure). Because the engine is cold, it's using petrol for nearly all of the urban part, and after that I'm doing 60-70 anyway. On the way home though, battery power is sufficient for nearly all of the four miles urban at the end, giving 35-37 MPG for the journey. I guess what the hybrid part does is introduce a much greater variability to the MPG for any given journey. If I lived half a mile closer to work my MPG for the homeward journey would exceed 40.
Economy aside (as I was expecting about 30 anyway despite the grand claims), my other beefs are with the 8 speed auto. In comfort mode, cruising behind someone at 50, flooring the accelerator to overtake does not do what I would expect. There's a delay of maybe a second before anything at all happens. Then it drops down some gears, then some more. It's maybe 1.5-2 seconds before you get full acceleration, which doesn't seem right to me? It's not really conducive to safe overtaking. Then there's Sport mode, which doesn't do it for me either. Why, with an 8 speed box, would you ever want it to be doing 2500 RPM at 30 on almost no throttle at all in town? Why not do what AMG/Jaguar etc do, which is still be doing 1250 RPM, but downshift as soon as you use more throttle, and not until then. It's a bit perplexing |
Interesting comments.
The problem with charging the battery from the engine as you drive, it is still using energy from the petrol. Give or take a bit of loss for energy conversion, there can't be much gain if any from that part. It is the regeneration side, where you recover wasted energy and convert back to useful battery power.
So it costs you in the morning to charge the battery, for the boost on the way back home.
Don't understand the gearbox behaviour, whether it is something to do with the hybrid software I've no idea, but my 535i is alive in normal and comfort mode, no delays in getting going from any speed. But I don't have the latest eco-pro mode, so you will be running different software anyway.
Incidentally my touring reads about 31mpg after two way trips of 12 miles each from cold. Conditions are quite easy, and about 8 miles in each leg is cruising at 60mph.
Mine just potters around at about 1,100rpm at 30mph.
HighlandPete