Hi everyone,

New to this forum, new to owning a Z, but a mature guy that just needs some help from those who don't help helping a newb.

Bottom line is this, I have an 04 Z coupe base model with 17" rims. Just got a set of 18" rims from a base model 370Z, so now I need tires and I'm torn on what size tires (width and aspect ratio) to put on them for daily driving. (but I don't want to lose handling - my stock Potenzas are pretty nice to me, don't want to go below that handling)

I know I need 15mm or 20mm spacers for the front, and will be buying some H&R or Ichiba spacers off Amazon shortly, but I'm on a tire hunt first, and looking for deals on tires as well. Not really wanting to pay full price as the tires I have are just fine for handling and tread. Those 18" rims though are pretty.

The 18" rims are 8" wide in front, and 9" wide in rear.

So...I've been told to pick up 225/45/18 for the front, and 255/40/18 for the rear.

Can I go with a 255/45/18 in rear? Can I go 265? I want the most comfort basically, so looking for every little bit of sidewall I can get, IFFFF it actually helps to a noticeable degree. The 265 question is more vanity lol, I just like the look of a wider tire, but I hear you actually lose handling on a wider tire? Or does that just apply to the front width more?

As you can see...I'm newbietastic in my newbieness, so all help is appreciated.

I won't bother you with tire brand recommendations, I just need to know the width and aspect ratio limits and then the pros and cons of such. (for tires I'm looking mainly at Ventus V12, or trying to find take-offs from another car or dealership - all help on where to find take offs are appreciated..so far haven't found any)

Thanks to all, even the wise guys who will take the time to call me a newb. heh

SavedbyGrace

 

Welcome and congratulations. Make your life simple. Tires have been done for you.

 

First,welcome!

What you need to look at first is the OEM tire diameters and find a tire in the 18" size to match.What you are doing is a "plus 1" change.
Remember,the rear tire is taller than the front.
Stock 17" is 112.5 high,rear 117.5
A 225/45/18 FRONT,OR A 245/40/18 would work.
Rear,235/45/18 or,265/40/18 would work.
Of course,depending on the size you select,it may not be available
from a specific tire manufacturer.
the Hankook V-12 is an excellent choice...got e'm on my Z.The Bridgestone's
on your car are junk compared to the evo v-12's

Why do you need spacers?
I'm not familiar with the 370 wheels..seems that there would be be no need.
Unless there is a clearance problem?

On the handling,it will not change...be a bit better.Personally,the more rubber
on the road,the better the car will handle.Yes,I'D GO FOR THE WIDER TREAD.
To bad you did not go for a 19" wheel.Looks better,handles better.
But,it appears that you are budget minded...good.Alot of take offs available.
Pretty soon 18's will be obsolete.

Again,you may want to do a search on tire size conversions online for the 350z.
Good luck

 

245/40 front on the 8, 275/40 rear on the 9. I'd even be ok with 255/40 on the front 8, but 255 is the max on an 8 and 275 is the max on a 9.

 

Largest I would use is a 245/40-18 front and 275/40-18. For comfort and longevity I would look to a sport all season tire like the Conti DWS or Michelin Pilot A/S+.

 

Thanks everyone for the help so far. Much appreciated.

Questions for my own understanding:

Why is a 265 width tire the widest I can go on a 9" rim? Sounds stupid I realize, but do tires basically have some flex where they can go on various width rims, they just bulge over a little on a thin rim, yet sit flush on the widest rim?

Is there a downside to a 265 over a 255? Other than cost.

Can a 255 really go on the front? I think I'd like the look, but am curious if there is a downside to this. How does tire width and offset affect each other?

The 370z rims I picked up will sit well inside the front wheel well on a 350z, so I'll be adding a 15mm spacer most likely, possibly a 20mm, but definitely one or the other. Can this situation handle a 255 wide? Would a 245 with higher sidewall ride smoother? My assumption is that a 255/35 is thinner on the sidewall than a 245/40, so the 245 would be a bit softer?

To those who say "I'd run no bigger than a 245/40/18 instead of a 245/45/18...what is the motivating factor? Will a 245/45 fill the wheel well too much? rub? Look weird?

Thanks again while I'm thinking of it...very much appreciate the help.

Last set:

Will the Conti DWS (the other tire I was looking at actually, for tread life and comfort yet with great handling (so I'm believing?) ride that much smoother than my Potenzas?

In what way are the Ventus V12's that much better than my Potenzas? Lots more stick in a curve? Just lots more stick from taking off? Softer ride and better handling? Details are a big help, as I'll be living with whatever tires I buy for a couple of years I figure.

A buddy is saying Potenza 970 (i think) are so much better than Ventus V12s, but he has a much heavier Volvo sports sedan...he knows cars inside and out, so I trust his input, but everyone has a buddy that steers their friend in a different direction than someone else lol, so I was looking for thoughts on his opinion?

Last...can I run 255/45/18 on my 18x9 370z rim? Or is that too tall?

Last last...will I need to have my speedo recalibrated after my switch to the 18s?

THANK YOU guys...I really am loving the Z, unreal how it transforms driving..so your help is really..well...a help.

SavedbyGrace

 

Forgot handling question....

I read in this forum in another post that skinny tires are best for handling, wide tires are best for 0-60 type straight line traction. Is this true?

And that wider tires hydroplane much easier?

If wider tires give me nothing but looks, then I lean toward the lower costing thinner tire, but if they improve handling then I'm interested. Better handling makes for safety through accuracy. (assuming a good driver)

Ok enough from me for one thread heh.

SavedbyGrace

 

245/40 front and 265 or 275/40 rears you will be fine. Handling will be fine, looks good etc etc.

 

That's what I thought, and thanks for input. I'm just trying to learn for the sake of understanding as well, so all extra info is appreciated.

Last question on this:

Can I put long lasting tread tires on rear, but stickier tires on front? Both rears and fronts of course would be high performance tires.

SavedbyGrace

 

You can if you want , the back end will want to come around on you and you can/will cause other handing problems. Just install matching tires, then you will go thru 2 sets of rear tires for every set of front tires.

 

For tires, if you are looking for a good general all season tire with good performance, good tread life, and won't break the bank, I'd look at the Yokohama AVID W4S . I have a set on a set of v.1 Track wheels and they are great. They handle very well in normal driving (although be a bit careful when breaking on a sweeper at 100 mph), have good tread wear and handle cold temps well. I don't drive the Z in snow, but I do drive it in cold wet weather, and dry weather below freezing in the winter. They were relatively inexpensive through Tire-Rack.

 

You can try 275 or 285 mm. Of course it may fall off the wheel. You want to push a safe width? Go for it.

 

Thx David, appreciate the help, I'm very very new to learning about cars.

And no, , I don't want to push a safe limit on tire width, I just haven't been understanding why a rim can have so many different widths fit. Before I've learned more I was thinking only one width tire would fit a specific width rim, I've learned there is some variation possible, but of course there are limits. Didn't realize though that a tire too wide could fall off the wheel...I just thought they would rub or simply not fit a wheel well. Now I know!

To the other post about Yokohamas: Thx for the suggestion on the Yokohamas, I'll look into that. Appreciate the info.

Question: Do the various tires only handle differently (dry conditions) when pushing a Z really hard, or can you feel a difference in normal driving on winding roads? I know different tires will behave differently in the rain and snow, but for a daily driver would I be missing the stick of my stock potenzas if I went to an all season tire if I weren't pushing the Z past normal sanity?

Thanks everyone,

SavedbyGrace

 

You can and will notice a differnce in handling between tires under normal conditions of backroad driving. Lets take the Hankook V12 and Nitto invo for example, both of these tires have soft sidewalls, you can feel the sidewall slightly in normal driving, more in backroad driving , and a lot when pushing the limits. Same tire also has a different feel dependent on wheel width, i like them run on the wider side of the manufacture specs. When running on the narrow side of wheel width the sidewall is more noticable while cornering.

Next we will say Nitto NT05, really stiff sidewall, you can feel the difference in sidewall in the bump in the road if you were to drive this tire back to back with an V12 or INVO. Cornering you will really feel the sidewall stiffness. Since it has such a stiff sidewall it has no tire rollover problems when run on the narrow side of manufacture specified wheel width.

If you want to push the car hard in the corners and do trackdays if wanted (you should keep crazy driving off the street), since you have a narrow wheel i suggest something like an NT05 with a 245/40 front and 275/40 rear.

 

For wheel-tire width see: http://www.tiresandco.ca/equivalency-tables-advice.html

Before buying tires check these test results: https://my350z.com/forum/showthread....ighlight=tires

 

Long story short is this question...

I currently am running 17" rims. Need new rears. I have 18" rims already.

Can I run an 18x9 rim and tire up front, with my 18x8.5 in back?

Reason is I have tires for the 18 x 8.5" rim, but not for the 18x9" rims, and my 17" rears are about to be Kojaked. (bald)

I want to just buy two tires instead of four, use my existing 225/50/18 on the rear, using my 18x8.5, and then run like a 235 or 245 on front if I can, on the 18x9, cutting my cost in half.

VERY new to cars and owning this Z...so apologies for sounding like Nerd B. Needingaclue from planet Dumbtopia.

Would love to just have to buy two fronts and be done with this...

Crazy? Or doable? and thanks for the help,

SavedbyGrace

 

It would probably drive fine, but I don't think I have ever seen that before.

I would just spend the money and get the correct tires. You shouldn't even be driving a Z if you can't afford two tires.

 

Seen this done on high hp evo's/sti's never on a Z. Im sure it can be done but it will affect the cars handling especially when it comes to turning. Plus, it will probably look akward.

 

Running 225/50 in the back would definately cause grip issues the car comes factory with 245's for a reason, seriously if you cant afford the tires sell the car.

 

switch the 225/50's to the 9's and get some 225/45's for the front