You need to keep the total circumference of the tire the same or you will change your gearing. He has effectively shortened his gearing and will now take more rpms to achieve the same speed. The profiles for 19" tires on the 370Z should be front/40/19 rear/35/19. His are F/35/19 R/30/19 . When his speedometer says he is doing 60mph, he will actually be doing about 50mph. 17-18% off. I can't believe how many cars I see with the wrong profile tires. People are obviously oblivious to the fact that they are not just changing how the tire looks. If you plus size you need to change aspects accordingly, and if you keep same wheel size then you must keep same aspect or you will be changing gearing and your speedometer.

Considering that the overall diameter of the 275/40/19 was 26.5 inches and the overall diameter of the 295/35/19 is 26 inches... not as noticeable as you're claiming

The front 245/40's was 26.7 and the 255/35's are 26.1, a bit more than the rears, but still not as noticeable as you claim.

Don't forget that while he did decrease the aspect ratio he also increased the width, which makes the change to overall diameter not as dramatic.

Also, just out of curiosity what size tire do you think he should have changed to? There aren't exactly a ton of options for changing tire size to a wider tire while maintaining the exact same overall diameter. It's only going to be "close".

And to keep the thread on track... here are some shots of my "meaty" tires
285/35/19's ... up FRONT and 305/30/19's in the rear
https://lh6.googleusercontent.com/-e...0/IMAG0021.jpg

https://lh6.googleusercontent.com/-s...9/_MG_7137.JPG

https://lh5.googleusercontent.com/-e...9/_MG_7160.JPG

so u are saying that no matter how wide said 19'' tires are you should always go with 40 front and 35 rear for side profile?? You do know that those numbers are directly proportional to the tire's width, right?

305/30/19 means sidewall is 30% of 305mm.
285/35/19 means sidewall is 35% of 285mm... etc etc

yeah, you're right. I plugged in the wrong numbers (only like -3%), but still... I would never go less. Your tires are a much better fit. I'm getting some meaty tires soon and I'll have some pics up. 20" Toyo R888 285/315

Tire Tech Information - Calculating Approximate Tire Dimensions

:tiphat:

based on your previous comments..

a 315/25/20 is smaller than OEM and so by your own words you shouldnt. but I think the r888 comes in 315/30/20 which would be taller than OEM.
a 285/30/20 for fronts is about perfect to oem though

The real question is what profile will you be running??

actually hes runnig 285/35/20 and 315/30/20 which are taller than OEM front and back... no bueno.

Good lord tall tires

Sent from my SPH-D710 using Tapatalk

Yeah those are the only tire options in 20" and they are just fine. I would rather go taller than smaller with performance upgrades I want first gear to be useable. 285/35/20 315/30/20

315*.30= 94.5mm sidewall
20*25.4= 508mm rim
508+94.5+94.5 = 697mm overall diameter (27.44in)

vs stock
275*.35=96.25mm sidewall
19*25.4= 482.6mm rim
482.6+96.25+96.25=675mm overall diameter (26.57in)

You're increasing your rear overall tire diameter by almost an inch.

315*.25= 78.75 mm sidewall
20*25.4 = 508mm rim
508+78.75+ 78.75 = 665.5 mm overall diameter (26.2in)
The 25's drop about .4in from stock whereas the 35's add almost a full inch in those sizes.

If I was going for 20's I'd go with the 25 and not the 30, but good luck. I think first gear will still be usable in either size, but like others have said... much taller than stock. I'd be interested to see how it looks and how far off your speedo is and if you have any rubbing issues etc.

There is no /25/20. He made a typo, those are the only tires available in 20". I used an offset and tire calculator and it says I will be doing 62 when my speedometer says 60. 2.8% I think it said. I don't have anything to consider because there are only 2 tires made in R888 20" - 315/30 285/35. If anyone knows of any other competition 20" tires I am all ears. I think maybe michelin, but I hate them. Other than that, I don't know of any other tire company that makes 20" competition DOT tires.

Time for some pics from the Hankook install... 305/30/19 rear and 275/35/19 front

thanks to EVOHUNTER for the great deal and service!

LOL at the guy bashing me about my tire choice and then when it comes time for him he does the same thing almost and then trys to justifiy it.









DAN

17-18%?!??! What are you smoking?
@ 60mphs, his speedometer will be off about 1 1/2 mph, resulting 61-62 mph

Do the math Tire size calculator

PM me.

Contemplating changing it up, again.

I use 315/30/18 rears and 295/30/18 fronts on 18x10.5 and 9.5 wheels. Looking for more wheel.

Some pic's of my set-up finally. :pics: Mich PSS's, 275/35-19, and 325/30-19 on 9.5" and 12" ForgeLine ZX3R. :tup:

constructive criticism? Front tire sidewall is a little to tall. And you need a drop! Other than that, sweet setup :tup:

I was thinking same thing but its OD is 25.6. Looks tall in pics.

Sorry, wrong tire size for the front. It's 275/35-19. So the OD is 26.6. I wanted to run the same set-up you have. But couldn't get these rims in a 20" diameter size. So I got the 19's instead. I wanted the tire OD to be close to stock with these rims.

Disregard my post. :inoutroflpuke:

The drop may be my winter project. Thinking with Ohlins.

uuuuh deep pockets.

Widower, empty nester about to retire in 6 years. :D GF makes more money then me. :tup:

:happydance:

Rusty it came out great! Thanks for being a great customer to work with.

255/295s
 

Attachment 44454

Attachment 44455

Attachment 44456does this make it

No, thank you. You was spot on with what I wanted. :tiphat: :tup: :happydance:

I have 275/35 Front and 305/30 Rear wrapping matte black TE37SL SuperLaps..

I'll post pics as soon as I can..

I'll be buying tires soon, getting something a little more all season.... but considering upsized rubber as we all like the look, stock rays, no spacers, hope to PC gunmetal while I'm at it.

Has anybody done the homework on the weight penalty, rotating mass and all that?

I figure the higher wear ratings/harder compounds will = a bit less traction and of the added width somewhat offsets that. I'm not tracking the car, just a fun commuter.

considering hankooks and continental DWS for anyone who cares. I would go Maxxis if they made them in my size to support the brand but it looks like they gave me a pass on this one.

Hankook V12s
 

I am really impressed with the Hankooks. Ride comfort. Acceleration is fine, no different.

Mind your older brother 350Z showing up?

HRE P43SC Satin Black
19x9.5 +20 19x11 +25
Toyo R888
265/30 & 305/30

http://i107.photobucket.com/albums/m...oyo_R888-3.jpg

:yum::tup:

245/40/19, 285/35/19

http://i44.tinypic.com/5wckra.jpg

meaty to me is 275/305 minimum!!!

I have to agree for the Z34. Don't you come standard with 285's?

Base - 225/245
Sport - 245/275
NISMO - 245/285

A couple people running 285's in the rear posted before me so I threw mine up.

With that said you all know that a 245/285 will work. Push the limit and stuff/try some of these; 275/305, 285/315 or, 295/335. :driving:

I think 305's are the limit if you're not boosted/blown. They look great too.

Here is pic of 315/295 setup. I'm going to 335/315 next

http://lh6.googleusercontent.com/-zd...B8204B9C8F.JPG

http://lh5.googleusercontent.com/-hP...0C8C17C3B9.JPG

Here is my skinny track setup 295/285

http://lh5.googleusercontent.com/-jB...4/JR1N7832.JPG

http://lh4.googleusercontent.com/-2r...4/JR1N7834.JPG