New 370z Wheels and Rims
 

I bought a new set of rims (19x9.5) front and (19x10.5) back. I got 275x40 in the back. Which tires size should i get for the front? 255x40 or 255x45?

OEM tire sizes:
245/40/19 front
275/35/19 rear
285/35/19 rear (nismo)

Go here:
https://tiresize.com/height-calculator/

And you can calculate the height of a tire

275/40/19 is TALLER than stock front
255/40 or 255/45 is TALLER than stock rear

I don't know if its off enough to mess with the eletronics or gearing, but it'll at minimum look stupid

Stick with 245/40 front, and if you go wider, adjust the aspect ratio accordingly using the calculator

There are a multiple wheel threads. I suggest you browse them to get an idea what people are running

You should probably learn what wheel offset is and how it affects tire sizing