 Honda started to introduce their third and final round of upgrades ahead of the Russian Grand Prix , focusing on the internal combustion engine and associated exhaust parts with the aim of improving the efficiency of the MGU @-@ H and gradually introducing new parts over the next three rounds . The engine ancillaries were reconfigured to allow for better packaging within the chassis , while the axial compressor was replaced with a more conventional — albeit smaller — design . The exhaust wastegate was also updated ahead of planned development for 2016 , with the exhaust outlets reconfigured to improve the engine 's power curve . Honda chose to focus on the internal combustion engine instead of directly addressing the problems with the MGU @-@ H as they felt that the problems could not be adequately addressed with their remaining allowance for in @-@ season development , and instead deferred development of the MGU @-@ H until the end of the season when the restrictions on development would be lifted . The upgrades were given to Alonso , with Button scheduled to receive them two rounds later at the Mexican Grand Prix . The updates were received positively by Alonso , who pointed out that he had been setting lap times that were faster than those recorded by Lewis Hamilton during the opening phase of the race , and that the team had identified the potential to gain two and a half seconds per lap in 2016 through further refining of the engine and by adopting aerodynamic design elements used by other teams . Button was less optimistic , pointing out that the engine would struggle in Mexico as the high altitude of the Autódromo Hermanos Rodríguez — some 2 @,@ 229 metres ( 7 @,@ 313 @.@ 0 ft ) above sea level — would leave the turbine down on power given the low density of the air . Although the team 's predictions of a difficult weekend were proven true after qualifying , they highlighted the deficit to the leading Mercedes through the less power @-@ dependent sectors of the circuit as being consistently within three tenths of a second , the narrowest the margin had been over the course of the season . 
