Hi i'm new to Mazda and have a question on 6spd manual parts interchange. my cousin donated me his 2015 Mazda 3 hatch in need of trans work. i found a 2012 Mazda 3 sedan with good trans/clutch etc. did a vin serach here and it shows the engines are boththe same , 2.0 skyactive-G , but shows different trans gear ratios except 1st/rev. also final drive 4.10 for the 2012, and 3.85 for the 2015. what i need to know is if they will interchange. don't care about it throwing off the speedo , just if it will fit. want to have the car on the road this winter for our spare vehicle. and my son will be 16 in May so............ thanks in advance for any experience or tips where to find this info. cheers James