Among all these criteria, I would like to examine two that I consider to be important, namely comfort, and cost-effectiveness.
The number of models and makes of cars available in the marketplace today is mind-boggling. It would hardly be possible to compare and contrast the merits and demerits of all such models. Instead, I shall be examining the transmission systems of only two models, namely the Honda CVT, and the THM 350.
The Turbo Hydra-Matic (THM) 350 is an automatic transmission system, largely used by General Motors (GM) and other automobile makers. It has a three-element hydraulic torque converter and two planetary gear sets. Other transmission components include four multiple-disc clutches, two roller clutches, and one intermediate overrun band, all of which act together as the friction elements. Working pressure is provided by a hydraulic system, which is pressurized by a gear type pump (TH350.netfirms.com).
A major weakness that has been pointed out in THM 350 is the second gear mechanism that uses intermediate roller clutches or sprag. This mechanism uses a band in place of clutch packs. As a result frequent failure of the second gear has been reported, particularly during racing campaigns, leading to increased cost of repairs. What is more, it lacks the desired level of smoothness in transmission, and provides less comfort. (DRW).
Another defect of this system is the occurrence of oil leaks around the engine and transmission, mostly from the transmission oil pan. Such leaks also get usually carried by air stream toward the rear of the vehicle (DRW).
The Honda CVT (continuously variable transmission) model comes from the Insight hybrid version of the company. Honda has a world reputation as a leader in the fuel efficiency of its cars. The Insight hybrid, a gasoline-electric model, has won several awards for innovative technology features, one among them being the CVT (Hks.com).
There are two models within the Insight hybrid. The first is a conventional 5-speed manual transmission. The other, commonly known as CVT, features a continuously variable automatic transmission. It is also called "Honda Multimatic transmission".
Normal transmission has gear ratios, or a fixed set of gear combinations. In a CVT transmission system, there are a virtually unlimited number of engine speeds, as against vehicle speed ratios. This is operated with the assistance of a computer that can intelligently select the Insight gasoline engine and electric motor to rotate at an optimal speed, no matter how fast the car is traveling. When the car is cruising under low power demand, the motor and engine also turns slowly. But they will turn much more rapidly when the vehicle is negotiating a climb, or accelerating. The greatest advantage of this type of transmission is the higher fuel efficiency in comparison to the standard automatic transmission system (Insightcentral).
In the normal automatic transmission system, gear changes give a certain amount of jerk. On the other hand, the CVT transmission has a much smoother transition, and gives a constantly flowing acceleration right from start to higher speeds.
Yet another advantage is the improved efficiency and acceleration due to the minimal loss of power in transmission, as