Copyright © 2020 Authors. This is an open-access article distributed under the creative commons attribution License, which permits unrestricted use, distribution, and reproduction in any medium provided the original work is properly cited. Comparison of CVT Performance with the Manual and Automatic Transmission for Evaluation the Fuel Consumption and Exhaust Emissions Qahtan Adnan Jawad 1, *, Abdulbaqi K. Ali 2 1,2 Department of Mechanical Engineering, College of Engineering, University of Basrah, Basrah, Iraq E-mail address: qahtan.jawad@yahoo.com , abdulbakiuob@yahoo.com Received: 18 September 2019; Accepted: 18 November 2019; Published: 2 February 2020 Abstract The Continuously Variable Transmission (CVT) is the blends of the efficiency of a manual transmission with the ease of using the automatic transmission. Furthermore, the CVT is a developed technology that has infinite gear ratios with a high fuel economy and high capabilities of acceleration. In this paper, a comparative study was performed of the CVT performance with the manual and automatic transmission for evaluation the fuel consumption and exhaust emissions in the parallel hybrid electric vehicle (HEV). In addition, the parallel HEV with the CVT gearbox is selected from the Advisor software and their simulation methods, and then replaced with manual and automatic transmission. Moreover, the pollutants of the catalytic converter were recorded with all the molecules reactions of the exhaust emissions. The performance evaluation of the CVT was conducted by using the different worldwide standard driving cycles to simulate driving conditions and evaluation the fuel consumption and exhaust emissions. The CVT gearbox produced the best performance results in fuel economy with a marked reduction in exhaust emissions compared with some of the results obtained from the manual and automatic transmission due to the high efficiency of controlling speed ratio, in addition to the great effect in the performance than other transmissions. Finally, the CVT gearbox is considered as a favorite in travel inside the cities for the hybrid vehicle, due to a little fuel consumption and high efficiency of controlling variant speed ratio. © 2020 The Authors. Published by the University of Basrah. Open-access article. Keywords: CVT Gearbox, Automated Manual Transmission, Automatic Transmission, Parallel HEV, Fuel Consumption, Exhaust Emissions. 1. Introduction A continuous variable transmission (CVT) has a continuously variable reduction ratio within a certain range, and providing an infinite number of gear ratios. Accordingly, the engine operates at the most economical conditions over a wide range of vehicle speeds [1]. Furthermore, many types of CVTs were developed, which have a high efficiency and presented better performance than other common transmissions. Generally, the CVTs have two pulleys the major and minor with a variable radius to transmit the power and have the combination of the chain or metal belt but they are not as widely used as a belt and chain CVTs. The two pulleys each including a pair of pulleys, one of which is fixed and the other is moved axially. In addition, to achieve better speed regulation, the effective radius of the major pulleys is reduced and increasing the radius of the minor pulleys or vice versa [2]. Therefore, several researchers are working to develop the CVT for using the features of CVT in all the vehicles. Where, Jian and Chau [3] in 2009, they proposed a novel Electronic-Continuously Variable Transmission (E-CVT) propulsion system using coaxial magnetic gearing. This propulsion system can achieve optimal fuel economy with minimum exhaust emission in addition to a good propulsion performance. The coaxial magnetic gears present a non- contact transmission torque, which overcoming of audible noise aroused from the mechanical planetary gears and low transmission efficiency. Finally, the operation modes were discussed and analyzed for the proposed system. Dragos et al. [4] in 2010, they presented the driving cycle model and control strategy of two types of transmission systems in vehicular with the continuously variable transmission. In addition, the CVT presents a continuous of infinitely variable gear ratios compared with the automatic transmission, which has five gear ratios. Finally, the simulation results are presented for five driving cycles to validate testing the developed control strategy for one driving cycle. Naderi et al. [5] in 2011, they presented a new fuzzy logic controller to promote the control speed of CVTs in vehicles. The simulation results of the controller demonstrate a low power consumption and root mean square error of output surface compared with results obtained from MATLAB. Hofman et al. [6] in 2012, they compared the moderate efficiency CVT push-belt with high efficiency automated manual transmission (AMT). In addition, the results showed that a significantly improving CO2 emission reduction of the switching topology, particularly for the hybrid electric vehicles that is depending on CVT. Furthermore, improving the relative CO2 emission reduction by selecting the optimal fixed topology. ISSN (Online): 23118385, ISSN (Print): 18146120 Basrah Journal for Engineering Sciences Journal homepage: www.bjes.edu.iq Basrah Journal for Engineering Sciences, Vol. 20, No. 1, (2020), 15-22