Taking our Lexus CT 200h through its paces showed us again the formidable economy potential that lies in the Toyota/Lexus designed hybrid drivetrain. It took us hardly any effort at all – except of course an anticitipative driving style and avoiding wide throttle openings, to reach a consumption of 4,4 liters/100 km, as we showed earlier, and we were astonished to see the figure even hover briefly lower on a quiet ride to Brussels the next day, to 4,3 liters/100 km.
On the subsequent return trip from Brussels with very heavy stop and go traffic, avoiding brisk accelerations let the CT 200h to use its battery power extensively, we achieved again an average of 4,4 liters/100 km. Indeed, accelerating with restraint, just moving along with the traffic flow, will besides the supportive E-power, also lead the E-CVT to keep choosing the lower rev ranges, and so the Atkinson cycle engine remains very efficient throughout. Remember, this Atkinson cycle also reintroduces cooled exhaust gases into the combustion chambers to make an additional contribution to reduced engine temperatures.
On top of all that, the smooth power transition performed by the E-CVT drivetrain and the low engine noise level contribute to a very “zen” driving experience. We tell you here a bit more of the technical side. The CT’s transmission plays a large part in the car’s efficiency because it incorporates little more than two motor-generators, some gears and a minimal amount of oil. There are no clutches and none of the friction associated with regular transmissions or the belt-and-pulley types of CVTs employed by a growing number of gas-only cars.
Electronically-controlled continuously variable transmissions
Electronically controlled continuously variable transmissions (E-CVT) offer an infinite number of gears within a broad range of ratios, and simultaneously handle inputs coming from the petrol engine and electric motor.
The intelligence of E-CVT is evident by the fact that it selects the optimal – that is, most efficient – gear ratio for any situation by constantly analysing vehicle speed, road conditions, engine power and driver input. When that split-second passes, it moves imperceptibly to the next calculated ratio through a clever combination of planetary gears.
More bodywork beauty soon…
In the meantime, the quote provided by Lexus Wijnegem proved not quite competitive, and we made an appointment in the third week of March with Carrosserie Vercruysse in Halle, near Brussels. Keep looking at our columns!
Hans Knol ten Bensel