1. BMW i8
- Model/Engine size:
- BMW i8 1.5 hybrid
- Fuel economy combined:
- 158.9 mpg *see text
Every once in a while, car designers are given the leeway to really apply their talents and get to create something truly astonishing. This is one of those moments. The i8 is BMW’s answer to keeping the performance car relevant and justifiable in a CO2 constrained world, which makes it a very important car in our book.
As you would expect, this has required some seriously challenging engineering. First the structure is radical, with an aluminium chassis (‘Drive module’) containing crash structure, suspension, batteries, petrol engine and electric motor, combined with a separate (‘Life module’) passenger cell made of cutting edge carbon fibre reinforced plastic (CFRP) which is around 50% lighter than steel and 30% lighter than aluminium.
The drivetrain is equally impressive with an electric motor driving the front wheels, a 1.5-litre, 3-cylinder turbo petrol engine powering the rear via a six-speed semi-automatic ‘box, and a modest-sized BMW developed lithium-ion battery pack in between in the vacant transmission tunnel. Thanks to a useful 34-mile pure electric range and a 42-litre petrol tank, you can cover over 330 miles in one go.
Of course how you cover those miles is configurable. You can force the i8 into front drive electric mode at speeds up to 75 mph, save the batteries for later or recharge the batteries via the petrol engine (rear-drive), combine the two for maximum performance or combine the two for efficiency (four-wheel drive). In full attack mode you get a very healthy 369 bhp and 420 lb ft of torque to play with.
So the i8 is properly quick and with 50:50 weight distribution, a sensible kerb weight, and a low centre of gravity it’s rapid through the corners too, but what about efficiency? Well we’ve said it before and we’ll say it again, the plug-in hybrid fuel consumption test produces crazy figures so ignore the official data. However BMW has helpfully provided some more realistic figures for comparison (see below).
The good news is that in electric-only mode it is very efficient, even for an electric car, which translates into very low CO2 emissions even if you use standard grid electricity. Once you start using the petrol engine CO2 emissions rise markedly but thanks to the hybrid ability, fuel consumption is significantly better than you have any right to expect from a car with this level of performance, so in context it is an efficient package.
Stunning looks, full on performance, a 34-mile electric range, cutting edge materials, and environmental responsibility combine to make the i8 one of the most exciting, advanced, and, crucially, desirable cars you can buy. How do you make a 21 Century performance car? Just ask BMW.
Official range: 34 miles.
Official electricity consumption: 119 Wh/km
Battery pack: 11.6 kWh (gross) 9.4 kWh (usable) Lithium-ion, 8 year 100,000 mile warranty
Recharge time: 3 pin socket 10A 240W less than 4 hours 30 mins; 3.7 kW 16A home wallbox less than 3 hours
Please note that CO2 emissions quoted for electric cars are not directly comparable to diesel and petrol cars. This is because CO2 emissions quoted are calculated by Green Car Guide and include the emissions created at the power station turning fuel (e.g. gas etc) into electricity and in transmitting and distributing the electricity to an end user. They do not include the actual production of the fuel (e.g. gas extraction and refinery emissions). Petrol and diesel emissions are supplied by car manufacturers and are based solely on the fuel burnt in the engine (tailpipe emissions) and do not include the production of the fuel or distribution to a fuel station. In practice this means that electric car emissions are over-estimated relative to petrol and diesel. For instance if an electric car, a petrol car, and a diesel car are all reported to emit 100 g/km CO2, the electric car actually has lower emissions.
- Fuel economy, extra urban:
- BMW estimates 35 - 40 mpg - approx 187 - 164 g/km CO2
- Fuel economy, urban:
- BMW estimates 56 mpg - approx 117 g/km CO2
- CO2 emissions:
- Officially 42 g/km. Average UK grid electricity (34 mile range) approx 45 g/km
- First year £0, then £440 a year for 5 years
- 1535 Kg
- BIK Company Car Tax (2018/19):
- Insurance group:
- 141 bhp (electric) 228 bhp (petrol) 369 bhp (system) bhp
- Max speed:
- 155 mph (limited) 75 mph (electric) mph
- 4.4 seconds
- 236 lb ft @ 3700 rpm (petrol) 184 lb ft (electric)