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[IS350]

Anyone know what the weight disparity is? And if the 19s are more, what they essentially slow the car down a bit, even if they added higher cornering numbers?

[eagletangogreen]

When I swapped my 18 to 19 on my 350z I would loose about 20 rwhp... So yes bigger wheels bigger tires = more rotational mass = less hp! If you dont believe me try it for your self go to a dyno and swap them out and you'll see..

[Sedan_Clan]

The OEM 19's actually weigh a pound or two less than the 18's.

[MrHarris]

I heard the 19's were around 30lb.

[lucid]

Originally Posted by MrHarris

I heard the 19's were around 30lb.

Not true. Not even close...

Why don't you guys just simply search this site and get the exact figures rather than guessing? There have been several threads with data on this...

[IS350]

Hmmm, haven't found any numbers yet. Must have been searching wrong threads. Any help is appreciated.

Even if the 19s DO weigh less (hard to believe) being bigger, is what's mentioned above true? More rotational mess, more resistance, loss of power?

[Sticky]

Originally Posted by IS350

Hmmm, haven't found any numbers yet. Must have been searching wrong threads. Any help is appreciated.

Even if the 19s DO weigh less (hard to believe) being bigger, is what's mentioned above true? More rotational mess, more resistance, loss of power?

The numbers you are looking for are in the weight loss thread. I believe you can find it just by searching for topics with "weight" in the name.

[MidwestBimmerFan]

The 19 inch wheel is slightly heavier but the 18 inch tire is also heavier than the 19 inch tire. So with the wheel and tire combo you save weight with the 19's. Hope that helps.

[lucid]

Originally Posted by IS350

Hmmm, haven't found any numbers yet. Must have been searching wrong threads. Any help is appreciated.

Even if the 19s DO weigh less (hard to believe) being bigger, is what's mentioned above true? More rotational mess, more resistance, loss of power?

The numbers were posted on several different threads by several different people who weighed their wheels. Anyway, I searched and found them:

Stock 19" wheels weigh 25.4/26.1 lbs.
Stock 18" wheels weigh 25.5/26.5 lbs

It is true that the 18" PS2s are about 1 lb heavier than the 19" PS2s (check tirerack on weight specs), so that would make the stock 18" setup heavier than the 19" setup.

Rotational inertia has to do with how mass is distributed along a rotation axis. The further away from the hub the mass is distributed the higher the rotational intertia, the slower the acceleration.

We don't have info on how mass is distributed exactly in the two setups, but it is highly likely for the 18" setup to have a slighly higher rotational inertia than the 19" setup.

The stock 19" wheels are rather nice IMO, in looks and in performance. One can obviously get lighter 19" wheels, but they'd be expensive and perhaps not as strong.

The 18" wheel setup has a better ride quality and would most likely perform better on the track though.

[Deda]

interesting thread!

[eagletangogreen]

Originally Posted by lucid

The numbers were posted on several different threads by several different people who weighed their wheels. Anyway, I searched and found them:

Stock 19" wheels weigh 25.4/26.1 lbs.
Stock 18" wheels weigh 25.5/26.5 lbs

It is true that the 18" PS2s are about 1 lb heavier than the 19" PS2s (check tirerack on weight specs), so that would make the stock 18" setup heavier than the 19" setup.

Rotational inertia has to do with how mass is distributed along a rotation axis. The further away from the hub the mass is distributed the higher the rotational intertia, the slower the acceleration.

We don't have info on how mass is distributed exactly in the two setups, but it is highly likely for the 18" setup to have a slighly higher rotational inertia than the 19" setup.

The stock 19" wheels are rather nice IMO, in looks and in performance. One can obviously get lighter 19" wheels, but they'd be expensive and perhaps not as strong.

The 18" wheel setup has a better ride quality and would most likely perform better on the track though.

Wow! those 18' are pigs!! These rear wheels on my Z ar 19x11 and only weigh 19lbs, I am thinking about getting some for the M.

[lucid]

Originally Posted by eagletangogreen

Wow! those 18' are pigs!! These rear wheels on my Z ar 19x11 and only weigh 19lbs, I am thinking about getting some for the M.

That's very light for 19x11 wheels, but I wouldn't want to drive on those in Boston.

What kind are they?

[IS350]

Originally Posted by lucid

The numbers were posted on several different threads by several different people who weighed their wheels. Anyway, I searched and found them:

Stock 19" wheels weigh 25.4/26.1 lbs.
Stock 18" wheels weigh 25.5/26.5 lbs

It is true that the 18" PS2s are about 1 lb heavier than the 19" PS2s (check tirerack on weight specs), so that would make the stock 18" setup heavier than the 19" setup.

Rotational inertia has to do with how mass is distributed along a rotation axis. The further away from the hub the mass is distributed the higher the rotational intertia, the slower the acceleration.

We don't have info on how mass is distributed exactly in the two setups, but it is highly likely for the 18" setup to have a slighly higher rotational inertia than the 19" setup.

The stock 19" wheels are rather nice IMO, in looks and in performance. One can obviously get lighter 19" wheels, but they'd be expensive and perhaps not as strong.

The 18" wheel setup has a better ride quality and would most likely perform better on the track though.

Great info! Thx for the insight! Have you or anyone else driven both set ups? What posed the question was because I noticed the 18" setup in most of the auto-mag test results and it got me thinking whether their would be much of a difference if any, in skid-pad 60 or 1/4 times with the better looking 19s.
Thx again!

[eagletangogreen]

Originally Posted by lucid

That's very light for 19x11 wheels, but I wouldn't want to drive on those in Boston.

What kind are they?

They are Volk RE30's They go for about $2800 shipped with out tires..

[eagletangogreen]

Originally Posted by IS350

Great info! Thx for the insight! Have you or anyone else driven both set ups? What posed the question was because I noticed the 18" setup in most of the auto-mag test results and it got me thinking whether their would be much of a difference if any, in skid-pad 60 or 1/4 times with the better looking 19s.
Thx again!

The only thing that I think would matter is maybe for the 1/4, if the diameter of the 19" are larger it will hold the gears a bit longer and allow you to run pass the traps in 3rd gear..

I am looking for a 27" diam DR tire to stick on my spare wheels so I can hold every gear longer so I dont have to shift into 4th... Shifting = time

[sayemthree]

the 19 combo (tire and wheel) weighs less. than the 18. search is your friend.

[IS350]

Originally Posted by sayemthree

the 19 combo (tire and wheel) weighs less. than the 18. search is your friend.

As mentioned... I'd searched... without much luck for the type of info this thread now offers. Thx though.

[IS350]

Originally Posted by eagletangogreen

The only thing that I think would matter is maybe for the 1/4, if the diameter of the 19" are larger it will hold the gears a bit longer and allow you to run pass the traps in 3rd gear..

Holding the gear offering a better time? Or worse?
I ask because in my best stock time of 13.2, came when I turned the ECT Pwr button of, which ACTUALLY does NOT allow the tranny to hold gears quite as long.

[Krueger///M3]

Originally Posted by IS350

As mentioned... I'd searched... without much luck for the type of info this thread now offers. Thx though.

It's ok, every once in a while you've got to remind him of this. http://www.m3post.com/forums/showthread.php?t=126289

[eagletangogreen]

Originally Posted by IS350

Holding the gear offering a better time? Or worse?
I ask because in my best stock time of 13.2, came when I turned the ECT Pwr button of, which ACTUALLY does NOT allow the tranny to hold gears quite as long.

Hum I never done a pass with it turned off?? It should better your time cuz you dont have to shift before the traps..

[IS350]

Originally Posted by eagletangogreen

Hum I never done a pass with it turned off?? It should better your time cuz you dont have to shift before the traps..

Give it a try. Be curious to see what you end up with!

[IS350]

Originally Posted by Krueger///M3

It's ok, every once in a while you've got to remind him of this. http://www.m3post.com/forums/showthread.php?t=126289

Wow, now THAT'S a thread!