The APX is a 7-seater (in reality a 5 + 2 with the two rear seats being occasional) four-wheel drive "Crossover" vehicle with a front mounted 300 hp supercharged V6 petrol engine. Weighing in at just 1570 kg and with a power to weight ratio of 191 hp per tonne, the APX has sportscar like performance of 5.4 seconds to 100 km/h (5.0 seconds to 60 mph) before reaching a top speed of 245 km/h (152 mph).
These performance figures are as good as the highest performing 4x4 "Crossover" vehicles from other brands with up to 195 hp per tonne. Crucially though, whereas those vehicles need higher output engines to compensate for heavy weight, APX does not. Combined fuel consumption for APX is estimated to be 8.7 litres / 100 km (or 32 mpg) .
APX is manufactured predominantly from aluminium in the form of high-pressure die-cast corner nodes, stampings and extrusions. It uses advanced assembly techniques, including adhesive bonding, self-piercing rivets and flow-drill screws for construction - joining techniques that Lotus calls Riv-Bonding.
APX is not just a Lotus Engineering concept, but a feasible prototype close to production; it is not a concept indicating a strategic direction of Lotus Cars; it is, however, a brilliant demonstration of VVA and the skills of the team from Lotus Engineering into what is regarded as the future of niche vehicle manufacture. APX is production feasible as all the components can be made cost effectively and in high niche volume (up to around 30,000 per year).
The Engine - 300 hp, 3-litre V6: Like the vehicle, the engine is not just a Lotus Engineering concept, but a feasible prototype close to production, however it is not a concept indicating a strategic powertrain direction of Lotus Cars.
Simon Wood, Director of Lotus Engineering explains the rationale behind building APX: "the first production car from Lotus to use the Versatile Vehicle Architecture will be the new mid engine "super sportscar", which will go into production in 2008. Lotus Cars customers eagerly await this vehicle that will be a class-leading and phenomenally high performing car.
The supercharged V6 is part of a family of normally aspirated and supercharged high performance engines which includes 2.2 litre and 3.0 litre normally aspirated derivatives. All of these engines are at the prototype stage and are production feasible, but are not currently planned for production. It uses a Rootes-type supercharger with a compact air - to - water Laminova - type charge cooler with separate parallel coolant system using its own water pump and heat exchangers allowing a charge temperature reduction of approximately 50 degrees Celcius.
Performance of the engine is maximum power of 224 kW (300 hp, 304 PS) at 6250 rpm and a torque of 360 Nm at 4500 rpm. 80% of peak torque is between 1500 rpm and maximum revs of 6500 rpm. Like all products from Lotus, it follows the adage of "performance through light weight", in that the engine weighs just 171 kg (fully dressed, dry weight). This gives a phenomenal specific output of around 1.31 kW/kg (1.7 hp/kg). Specific performance is 74.6 kW / litre (100 hp / litre, 101.3 PS / litre).
Example VVA families
The following represents illustrative VVA families that could be achieved:
Front engine 4WD crossover 15,000 / year Mid engine RWD supercar 5,000 Front engine RWD coupe 10,000 Front engine RWD saloon 20,000
Front engine FWD coupe 10,000
Front engine 4WD SUV 25,000
Mid engine RWD coupe 5,000
Front engine FWD saloon 25,000
Front engine 4WD crossover 30,000 - i.e. APX by Lotus Engineering