Ok well for starters my back ground is in trucks and off roading. So my scenario example is as follows. I have an 88 4runner. stock this truck came with 4.10 gears and a 4 cylinder engine and 5 spd transmission. Along with this stock tire size is roughly 28 inches in height. Now granted I have lifted it and now run a 4.88 gear ration and a 35" tire which puts me about 3mph off of factory specs by regearing. Now my next steop up in gearing would be a 5.29 ratio which would result in an over revolution with that tire size.

So my current car is an 04 coupe 5at with stock 18" wheels (no clue on metric height converted to inches). I have seen the car also with 17" wheels and would assume that this has a different ratio in it as well. And then of course there are the factory 19" options. My question comes about to gearing what sizes are available and what did it come with. 3.35, 3.5 3.7 3.9 4.08.

I have learned that you should regear if you go to a larger wheel and tire size to get back to stock specks. I have been contemplating going to 20" wheels and with the craptacular city economy a MPG saved is earned in the long run. ( I have delt with Nissan for years and yes they have gotten S***y mileage since the 80's I had a 1st gen pathfinder that stock got 240 MPT and after lifting it without regearing I was lucky to see 155 MPT.

So what have you got for me? I don't mind searching thats how I found out about the gear ratios. so :flamesuit on:

 

I had the stock 18's on mine, now I have the 19's.. I'm scavenging for all the parts so I can get my 4.08 gear set up..

Auto G35= 3.3 gears
Manual G35= 3.5 gears
Auto M35= 3.7 gears.

I've heard the best one to get is the Nismo 4.083 gears with the Nismo LSD.

 

So what might be a possibility for me is to just pull the entire rear of an m35 cv's and third member? they are the same track width correct?

 

07+ sedan ATs are 3.692 (3.7)

OP you have 3.3 and going to 3.7 is a good choice

As for the wheels - 17, 18 and 19 are all roughly the same diamter with the OEM size tires... the smaller the wheel, the taller the profile - so the overall diameter is always the same. But I'm sure you know this...

 

he has an AT... 4.0 would not be a good choice.