I'm pretty new with this and I recently just got a g35 so I'm looking on putting smaller tires and rims because i heard you can be faster with them, but do yous recommend it like in durability.. will they burn faster or waste more gas i really don't know will you guys put your opinions here and recommendations.

 

This has been mentioned once maybe twice here on DRIVER, NO smaller tires will just make your G35 extreemly unstable! Nissan puts these size tires on our cars for a reason, if anything larger tires will give our cars more traction and stability at speed. Ya gotta wonder where these crazy thoughts and ideas come from....
Gary

 

Oh boy. This is going to be an interesting thread.

Yes a smaller overall diameter (wheel and tire) will result in a change in gear ratio. The car can accelerate faster off the line, but at a cost.
If you are looking at increasing off the line performance then research gearing.
A much easier and cheaper way while still maintaining the look and integrity of your car is to swap the pumpkin.

Search: Rear end, pumpkin swap, gearing swap, final drive, what the affects of a lower gear has on your car, where you can get a new pumpkin, how to swap the pumpkin, if you do swap the pumkin, which one and from which car. Side affects of changing the gearing. Over gearing. The list of searchable terms goes on and on.
Running smaller diameter wheels should not be one of the items you search for because you make your car look horrible trying to acheive what you can by a simple change in the gearing.