Although it seems to take design cues from GM's old EV1 electric vehicle, the XL1 from Volkswagen is a plug-in hybrid billed as the most fuel-efficient production car in the world. It has a European combined fuel consumption rating of 261 mpg. The two-seat coupe can also cover up to 32 miles in all-electric mode before the ICE kicks in.

The high mpg rating comes out of the car's light weight (1,753 lb), aerodynamics (Cd 0.19), and a low center of gravity. The German car maker got the weight down through use of such measures as carbon fiber-reinforced plastic for the monocoque structure and body panels,  a windshield made of super-thin glass, and polycarbonate side windows. Several chassis components are also aluminum.

Separated at birth? The XL1 and the EV1.Separated at birth? The XL1 and the EV1.The XL1 cruises  at 62 mph while using just 8.3 hp. In all-electric mode, it consumes less than 0.1 kWh to cover more than a kilometer. The XL1 emits just 21 gm/km of CO2 when its  47-hp two-cylinder TDI turbo-diesel runs. (Noteworthy in that plug-in hybrids such as the Volt typically carry four-cylinder ICEs.)  It also carries a 27-hp electric motor, a seven-speed DSG dual-clutch automatic transmission, and a lithium-ion battery pack for power. The XL1 also has a top speed of 99 mph and can accelerate from 0 to 62 mph in 12.7 sec.

Also in the interest of energy efficiency, the two occupants of the XL1 sit slightly offset, side by side, almost like a conventional vehicle. The XL1 measures 153.1 × 65.6 × 45.4 in. By comparison, a  Porsche Boxster is 5.1 in taller.

(For the curious, GM's EV1 measured 169.7 × 69.5 × 50.5 in. and weighed 3,086 lb with lead-acid batteries, 2,908 lb with NiMH batteries.)

And those who crave the plug-in hybrid experience but who think the XL1 might be too tame can take heart: Car buyers in that camp can soon get themselves a plug-in hybrid Lamborghini. According to WardsAuto, the auto maker (now a subsidiary of Audi AG) is prepared to launch the final development phase of its Urus Super CUV hybrid. Volkswagen Group, which includes Audi, recently green-lighted a €200,000 ($268,000) Bentley CUV codenamed Falcon.

Lamborghini's Urus concept.Lamborghini's Urus concept.The two projects are synergistic, Wards says. Both would share cost-intensive components with Audi as well. The combination of the vehicle’s Iturbi V-8 engine and electric motors reportedly will produce 670 hp. Reports are that the Urus will share the modular platform developed for the next-generation Audi Q7. Unlike the Bentley, which will share the Q7’s long wheelbase, the Lamborghini’s will be shorter. The production version of the Urus is expected to reach the market in 2017, although WardsAuto thinks it might arrive sooner.