maximum sidewall
 

Hi all,

I like to drive fast on all surfaces, including gravel.

I'd like to try running a 275/45-18 tire square on my base model 2016. Possible? Any problems outside of inaccurate speedo?

I'll need new wheels of course, so I'll have to figure out an offset that will keep the tires inside the fenders and free throughout the suspension movement. Guidance please?

Thanks,
Tobin.

Stock wheel diameter is 26.7 and 26.9 inhces rear

Here is a wheel height calculator:
https://tiresize.com/height-calculator/

But i really don't know what the goal here is. Are you just trying to get a more comfortable ride on crappy roads? Or are you trying to get a performance upgrade?

both, I guess. when cornering hard on uneven surfaces / bumps, the car moves around too much. it'll 'chatter' across lanes, sideways, etc.

i'm sure suspension upgrades could help, but with a tire sidewall increase I'm hoping to soak up those bumps and keep the car under better control. comfort will be improved too I suppose but it's not the main goal.

a 275/45/18 is 27.7, so an inch larger. I assume the car has room for an inch? so long as I figure out the offsets correctly?

you're looking for a solution in the wrong place

but the path for better cornering is well-known.

good coilovers
stickier tires
SPL everything
bigger front bar

none of the solutions involve turning your Z into a monster truck

Go nuts!!!!

coilovers would certainly help...

but the problem is the car is essentially airborne for very short periods. so more rigidity and sticker tires aren't really going to help that.

ha yea, something like that

I run 245/50/18 on all 4 corners for winter on a set of 350Z wheels with conservative offset and width. My car is a '11 Sport. The tires have an OD approximately one inch larger to boost ground clearance; the wheel offset also helps. If your base brakes could be accommodated, I would pick 17" wheels.

What the **** driving are you doing in which your car is airborne?

He's in BC Canuckistan. So it's ralley-cross. Dirt roads are the main highway.

the whole car is never airborne.

go find the worst pavement in your area... drive at high speed, and hit said pavement while cornering. you will find the car chatters, bangs, and moves sideways.

that's cuz the wheel hits the bump, and is deflected upwards very quickly. the suspension's job is to get it back to the ground in a controlled fashion. but that downwards travel takes time. during that time (which will only be a fraction of a second) you have zero traction - obviously, because your tire is in air.

pneumatic tires are pretty good at absorbing these high frequency hits, and they're better the more air volume available. more sidewall equals more air. of course if you're driving mostly on good pavement, there are downsides, but you know about that.

They are crazy in BC, in Alberta we avoid these issues by driving dogsleds and living in igloos.

:rofl2:

You need a Sherp 4x4.

i mean, yeah. Based on the conditions and how you want to drive, you have the wrong chassis

or

wrong type of vehicle

Any particular brand or compound tire you looking at?
Sounds like you need an all terrain tire; at minimum-an open shoulder A/S :ugh2:

Tires alone aren't going to do you a lot of good. The reason the tires are losing contact is because, among other things, your shocks are too weak and allowing the tires to fly up in the air. The "chatter" is because the tires are bouncing; weak shocks. It is more involved than just shocks - lots of suspension threads on this site.

I was going to say something close to what you said. But he has his heart set on tires only. So I let it go.

:iagree:

Maybe avoid potholes and uneven pavement by looking ahead??:twocents:

In all seriousness, you are likely to spend just as much on a new set of tires/wheels for your 18" setup, than you would for a very decent set of coilovers. Decently valved coilovers, combined with a properly aligned car, will do wonders and provide you with options down the road to run pretty aggressive wheel/tire combos.

I definitely don't! suspension is next, I just need tires this season.

it's just a bit of sidewall ;) hardly a reason to buy a whole new car.

I was planning on putting off suspension upgrades until after I do the exhaust and intake, but based on the suggestions on this thread maybe I will do it right after the diff and brakes.

it's not a question of wheels vs suspension - both have to be done. I just have to do wheels first, because I need new tires for this spring/summer.

If you’re keeping your base brakes; you can easily fit 17” diameter wheels on your Z, allowing more sidewall-while keeping the 27” Target diameter for accurate speedometer :ugh2: