The aim of this project is to study the fuel consumption from the effect of tire pressure and tray volume. In order to tire pressure is consist of 2 conditions by: Road test and Roller test Bench. Their test is classified by 3 cases: standard tire pressure lower standard tire pressure and upper standard tire pressure. Furthermore the lower and upper standard tire pressure was compared with standard tire pressure. In case of seal and unseal of the tray volume was test with 2 postulates by Road test and water tunnel (model). The results of experiment with 3 cases of tire pressure found that the lower standard tire pressure (25/37 psi) given to the maximum fuel consumption when compare with standard tire pressure 4.6%. While the minimum fuel consumption is upper standard tire pressure (33/45 psi) or 1.29%. Furthermore the trend of those conditions was in the same direction. For the result of test in term of seal and unseal of the tray volume discovered to the fuel consumption in case of seal is lower than unseal of the tray volume 1.63%. And the result of test of the water tunnel has been the same direction with the Road test.

Nowadays one of the automotive engineering is conductivity of brake pads playing a role in friction coefficient which means safety of customer. Thus thermal properties have been improved using composited materials. This project aims to study the conductivity behavior of 3 different brake pads which are supported by the company Compact International (1994) Ltd. For experimental works temperature based on brake condition was simulated from 200 to 400°C and cooled down from 400 to 200°C at 1 5 and 8 MPa of pressure respectively. By standard JIS D4413 testing condition of pressure was referred. The non-linear of conductivity value are calculated from the temperature under steady state condition. As a result of testing there are several of parameters effecting on the non-linear conductivity value. The brake pad that is a mix of high-fiber occurs the fluctuation of thermal conductivity. At the same time lubricant in the brake pad cause the stability of conductivity value in different temperature range at the same pressure. On the other hand the brake pad mixed hi-copper inspires the narrow range of conductivity value in different pressures at the same temperature. Moreover the conductivity value as a mention is inversely proportion with the coefficient of kinetic friction.

Nowadays an automotive industry steadily has been growing and playing a major role on economy development for many years. The crash box is one of the most important parts for safety but it was found that the crash boxes manufactured domestically are not met international standard requirements. This is due to process and material limitation. This process for automotive safety test requires high budget and there is unclear approach for specific test. Therefore a study of crash boxes referred to energy absorption project was conducted as the alternative materials for product. Consequently this project was aimed to design and test crash boxes which made from the diversity of the alternative materials such as aluminum aluminum reinforced by foam resin reinforced by fiberglass resin reinforced by water hyacinth and resin reinforced by water hyacinth and husk. In addition it was also emphasized in studying energy absorption behavior and physical deformation of crash boxes after dynamic and static energy being applied. The experimental works were applied for these tests in partly referenced to US NCAP and ECE R29 standard for automobile collision test. Testing all types of crash boxes indicated that the aluminum reinforced by foam type was able to absorb energy at 189 MJ/m3. It is higher than resin reinforced by water hyacinth and husk at 1 MJ/m3 as 188 times. Furthermore the comparison of the energy absorption (per unit volume) between the aluminum reinforced by foam type and the steel type from the previous project equivalent 20 MJ/m3 found that it is 8.45 times of difference. While the front impact test was not successful because the size of crash boxes was not suitable for the energy volume. It was a cause for non-available calculation of energy absorption value.

A disc brake is one of important auto parts for automotive industry which effected directly to life safety. The wear of brake rotor war affected to the brake efficiency. Lf the wear of rotor was discovered while operating the risk of accident shall be reduced. Therefore a study of disc wear affected to brake distance was the one of alternative for the brake efficiency testing. From this reason the aim of project is to test brake efficiency from the wear of brake rotor with the experiment conditions from JASO C 406 [1]. By the test conditions are focused on 3 cases of the wear: rotor little roughness rotor and abundant roughness rotor. The conditions of experiment consist of 100 200 และ 3000C on the rotor surface operating pressure 2 4 and 6 MPa initial speed before brake applied 50 and 80 km/hr. Based on the result of experiment was revealed that the braking distance deceleration and the brake ability with deceleration per unit of area. The result of experiment shown that the ordinary rotor at 6 MPa 300 0C and 50 km/hr. is given to the shortest of braking distance 69.7 m. Although the average of deceleration and the brake ability is take up on little roughness rotor. In case of the longest braking distance was occurred on the abundant roughness rotor. However from this study is discovered to the high temperature and the high pressure is significant to the braking distance shortened.

Braking system is the main of safety for motor vehicle. It uses to slow down or stop of vehicle movement. Normally braking system can not to adjustable in the recently. The brake efficiency depends up on to 3 factors by the perfection of brake equipment friction coefficient of road surface and the brake proportional. The factor of the perfection of brake equipment and friction coefficient of road surface can not be control. But in case of the brake proportional can be set up to suitable. In the other hand if the brake ratio is unsuitable the driver may be risk to danger from the loss of vehicle control. From this reason the aim of project is to study of the brake proportional affected to vehicle control. By the test condition consist of 2 cases: braking performance testing and vehicle stability testing. In case of braking performance testing is consider to deceleration braking distance and time of braking. For the vehicle stability testing is determined with yaw angle pitch angle sideslip angle and wheel lock up condition. However the bolt of testing is the road test and using the FMCSA standard for the testing guideline. The result of the braking performance testing shown the maximum deceleration was appeared on brake proportional 80:20. But the braking distance and time of braking are least because of the non-continuously of deceleration from the driver. Therefore the braking distance and time of braking depend on the continuously of deceleration. In term of vehicle stability testing discovered to the each of brake proportional are risk to danger for the driver especially on the 100:0 because of the value of sideslip angle is more than the critical point and the rear axle is lock up.