TechTalk Daihatsu Rocky D-CVT

Published on October 9th, 2020 | by Daniel Sherman Fernandez

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Direct Shift-CVT Explained By Experts

We are not an automotive engineer and when we are asked what are the added benefits (fuel saving is the most well know reason) of the continuously variable transmission (CVT) we always refer to the internet search engine to get the answers from the experts. 

Now with more Malaysians coming into new car ownership and having little help from showroom sales people with detailed explanations on the use of CVT in new cars, we have decided to present the answer as simple as possible for all to understand.

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A number of car manufacturers in the last 15 years or so have appreciated the CVT’s benefits of fuel economy and seamless acceleration from an earlier stage and it was Nissan of Japan that was the world’s first car manufacturer to offer CVTs for engine displacements as large as 3.5 liters. 

Today, Nissan’s CVT technology offers smooth and fuel-efficient “fun-to-drive” performance in an extensive range of Nissan models, from the compact class all the way up to high-powered luxury vehicles.

More importantly, the soon to arrive Perodua crossover, codenamed the DL 55 which is a rebadged Daihatsu Rocky will be using the latest version of CVT, which is the Direct Shift-CVT.

Recent years have seen the continued development of fuel efficient and hybrid vehicles that emit reduced levels of exhaust gases, including carbon dioxide (CO2), due to the increasing demands on the automobile industry by many governments around the world, including Malaysia for environmental protective measures and improved fuel mileage. 

In order to provide optimal gear ratios for all driving conditions, a continuously variable transmission (CVT) that allows the engine performance to operate at peak efficiency was developed that replaces the conventional fixed gear ratio transmissions with a combined planetary gear and torque converter structure.

Daihatsu Rocky_JDM

As crude oil prices slowly continue to rise right now, compact vehicle manufacturers have an urgent need to focus sales strategies on improved fuel economy. In this regard, the CVT offers a measure of support in the improvement of fuel mileage. 

Up to recently, compact vehicles have been equipped with either a low-cost manual transmission (M/T) that provides good fuel mileage or a clutch-free, or fixed gear-ratio automatic transmission (A/T) that is comparatively easy to drive. 

The CVT is designed to be able to offer both the driveability of an A/T together with good fuel economy. Since the CVT is continuously changing transmission speed there is no loss of drive power during gear shifting and this capability for smooth operation is a distinctive feature of the CVT. 

Direct Shift-CVT

Compared to a conventional A/T, the CVT provides a 10 per cent improvement in petrol mileage and, depending on the circumstances, it can offer better fuel mileage than an M/T. It also provides reduced carbon dioxide (CO2) levels. The reasons why the CVT has not previously been common equipment for compact vehicles is the extensive development costs involved as well as the high cost of the CVT main body. In addition to the unavoidable problem of low cost, a CVT must be small-sized and low-weight in order to be suitable for equipping to compact vehicles like the new Perodua DL 55.

Daihatsu developed and equipped a CVT as standard equipment for their compact vehicles that were on sale in Japan.

Toyota’s new Direct-Shift Continuously Variable Transmission (DCVT) combines features from an automatic transmission, a CVT, and a manual transmission. It is used in the Lexus UX 200 crossover and the Toyota Corolla.

Lexus new Direct-Shift Continuously Variable Transmission (DCVT) combines features from an automatic transmission, a CVT, and a manual transmission. The CVT uses a fixed, mechanical first gear ratio for starting from a stop, and then switches over to the CVT pulleys for higher vehicle speeds.

Toyota’s New Direct Shift-CVT

Toyota listened to their drivers and made some exciting changes to their CVT. The new system will use a launch gear to give drivers the feel of a traditional transmission, and it will improve its efficiency in the lower gear ratios. This launch gear is just like the first gear in a regular transmission, and as the vehicle starts to speed up, it switches out and starts working as a normal CVT. By using these fixed ratio gears, the new CVT will improve the belt efficiency and increase the shift speed ratio, resulting in better performance.

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