bigger aspect ratio will it help me?

Waiz

One thing it will probably do it improve ride quality by being on a larger sidewall.

30 is too low a profile for a 19 in the sizing that you have, in a 295 yes but not 245-275

xnismo370zx

So i should def. Get 40 skip the 35. And will ot make the ride higher? Meaning raise the car? That would suck but going on input and any is good .

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AntiVenom

Yes, skip the 35, go for 40 on the front, and 35 on the rear in stock sizes. That is unless you want to go wider. There are some performance advantages to wider tires, but unless you are gonna be driving your car hard, the stock tire sizes are going to be fine.

Yes, it will raise your car.

My suggestions:
-familiarize yourself with a tire size calculator
Tire Size Calculator & Converter, Tire Size Conversion | Discount Tire
this not only allows you to compare the difference in whatever tire size you might be interested in. it also has diagrams that explain the terms. if you are in to cars, this is critically important knowledge.

-nobody lowers their ride height by reducing sidewall size, or at least not anybody that is interested in the performance of the car. as you already know, doing this might lower the car, but it leaves you with unsightly fender gaps (i.e. looking like a 4x4). if you want a low car. get the right tire sizes and get some lowering springs (inexpensive way to drop your ride).

xnismo370zx

No thats what i went with when i bought the rims. So the intentions were never to lower it based on tires. I want performance. Traction sucks when you get on it and the gap is killing me.

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AntiVenom

Completely understand.

Trust me you will be happy with the appearance if you go back to stock sized tires and pick up a set of springs.

but before you do that check out this thread. might give you some inspiration to go with a different tire size and also give you an idea of what the car looks like dropped with normal aspect ratios for the Z
[Official] 370z wheel fitment guide (pics/specs) only

edit: this is my 100th post woohoo

xnismo370zx

Appreciate it. One more question how wide could i go on my rims?

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