Guys, does anybody know if there are any major differences between the Chevy Volt and the Vauxhall / Opel Ampera?
I mean to say, a Toyota Prius as sold in the USA did not have an pure EV mode where as the ones sold in Europe did. I do not expect something like that but am i missing something obvious? As far as i am aware the Chevy is not made in England where as the Vauxhall is?
Having put my money down on one of them I have a pretty good idea of the differences.
Both the Ampera and the Volt are built on the same Detroit-Hamtrack production line and shipped over. They have identical drive trains and even the insides look identical. Performance figures are also identical.
The main difference is the banana shaped front light assembly on the Ampera giving it a distinctive look. Also the Ampera is available in a wider range of colours in the UK than the Volt: there are 7 Volt colours in the US and they're only importing 4 of those for the Volt but all 7 are available for the Ampera. The Ampera has 3 trim levels: the mid range level 'Electron' has the same features as the UK Volt (leather seats, parking sensors, reversing camera); the top level 'Positiv' adds the satnav and Bose stereo which are also available on the Volt for the same price increment but without getting a different model name. The Ampera is £2,250 more expensive than the equivalent Volt but later this year there will be an entry level Ampera with cloth seats and without parking sensors or camera that will (they say) be priced at the same £29,995 OTR as the Volt. Both course charge identical supplements for any colour that isn't black.
The other significant difference is that the Volt has 2 UK dealers and the Ampera has 20 (both number may grow over time but those are the initial figures). I decided that having the nearest dealer 100 miles from me (Cambridge Chevrolet) rather than 30 miles away (Swindon Vauxhall dealer) was worth the £2k saving. Also unlike a lot of the reviews I actually prefer the Volt's looks though I would have liked a wider choice of colours. My Volt should arrive sometime in May.
Both have a 1.4 Liter petrol engine? Why is it that big? You should only need a 10KW power source to keep going for ever at 70mph. By my estimates you would only need a 0.5 or 0.6 Liter engine. Thoughts?!
Maybe to keep going that's all you need, but you also need to be able to accelerate up to 70mph in the first place, also you need power when driving uphill.
The way the Volt/Ampera works is that it has two motor/generators and one ICE. Under normal battery conditions the main motor does everything up to about 60mph at which point the second motor is brought in to reduce the rpm of the main motor back down into its most efficient range.
When the battery is depleted the ICE drives the secondary motor as a generator and the main motor continues to drive the car from the resulting electricity: there may be some slight charging of the battery in this mode if it gets too low, but basically it aims to sustain the charge but not increase it.
The fun starts when you accelerate above about 60mph in this mode as again it brings the second motor into the drive system only now that motor is directly coupled to the ICE so actually the ICE is providing power directly to the wheels. Someone on one of the US forums recorded all the motor states over a range of conditions and rather strangely (I thought) when accelerating from 90mph to 100mph the main motor was actually running backwards generating power for the secondary motor: so both ICE and secondary motor were providing torque on the same shaft.
I think the bottom line is that if the ICE and generator were completely separate from the wheels they could run at a constant speed and then a smaller ICE might be sufficient, but because the two motors are used together in varying speed combinations that means the ICE also has to vary its speed so it has to be bigger than would otherwise be the case.
Edit to add: I think you're right to take the 235mpg with a pinch of salt, but not necessarily the way you think. The actual figure is about 56mpg combined when running purely on petrol and infinite on battery (since the official figures ignore the electricity costs). That means if you only ever drive on battery you can get mpg figures in the thousands: there's a leader-board at voltstats.net which shows at least 20 Volt owners with better than 1000mpg, but they still come in about 90mpge when you account for the electricity. On the other hand if you consistently drive way beyond the petrol range you'll get a much lower figure.