why 18'' wheels more popular on track?
 

don't consider the price and weight.
Is handling better than 19''?

i have also wondered this

Umm price and weight are the only factors that matter.

1. They're lighter (being lighter is suppose to equate to better handling)
2. Tires for 18s are cheaper

:iagree:

Half the grippy tires don't come in 19s

Cheap tires=mega fun

19" is a show tire. 20" is a bigger show tire.

While going 90 mph around a corner, you don't give a f@ck what your car looks like.

18" wheel = lighter than same brand 19" wheel(it makes a big diff)

18" tire cheaper than 19" tire.

can lower car 1/2" more.

Most good tires for the 370z come in 18" wheel size.

Lol pretty much.

And even if a 19" wheel is the same weight as an 18", it's really not. Its heavier because it has 1 more inch of outer weight adding to you're rolling resistance.

If you swing a 5lbs weight in you hand in a 1 foot circle it's pretty easy and fast rpms. Swing the same weight at your max arm extension and it can pop your shoulder out of its socket trying to go to fast.

17" & 18"
 

can run tires with more rubber. Much smoother ride, also many more tires available, like for drag racing. Not a fan of big wheels & thin/little rubber if there's no reason for them. If you do some road type of driving that need very firm/hard tires then.....ok. Not a fan of spacers if the car will do some hard driving. Working with the wheel sellers/manufacturers will help get the size, right off set & look without the risk of having wheel spacers.

Maybe it's just me, but if I can get what I want without those, I'm happy. Only one pick in my home page. 17" wheels wide tires & perfect level side view. Check it out.

Also, if your tire/wheel combo actually reduces the outer diameter and ride height as mentioned above, that effectively gives you a small boost in gearing, like changing your rear end ratio.

The only flip side of a 19 vs 18 is a smaller sidewall which means less flex around a corner, which in turn would aid in track times... BUT that being said an 18 on the 370z would still use a 35-40 series profile which is still low.

For drag racing a higher sidewall in the rear may help off the line.

Overall an 18 inch would typically be lighter using the same rim comparison but a Volk CE28 in a 19 inch weighs around 19-20 pounds vs a Rota knock off weight more in an 18 inch. So this comparison must be 18 vs 19 in the same exact wheel and same tire brand combo and width.

Handling can be tweaked with the slightest adjustments like alignment, tire pressure etc.

The only real way to test if you are that specific to getting the lowest track times is testing. We all know they didn't just slap the GTR together and go "I bet she goes fast"... NOpe they continually tested at the Nurbergring track over and over and made tweaks.

-Chad

There's such a thing as too little compliance.

Smaller sidewall does not automatically mean more grip. There's plenty of folks out there that run 18's rather than 19's in order to get a slightly taller sidewall and more compliance without increasing OD.

A fun video I remember seeing years ago, using a 350z and comparing 18 v 19 inch wheel sizes:

I agree on the lines for racing and track the 18" rim has a better choice and more of a selection for what you can run for tires. You can run a better side wall for autoX and track racing in my opinion specially if your car is lowered. They also can run a few bucks cheaper, rim and tire. Then top that with the weight savings of a 18" rim over a 19" rim which i.e. the Enkei RPF1 in a 19x10 is 21.30lbs and the 18x10 is 18.45


:icon14: synolimit.... :confused: really.... That answer would fail you in Physics pertaining to the physics of a wheel. And this is were you get your participation medals thanks for trying.

He's referencing the change in MOI as the mass distribution shifts outward. The effect is right, the wording just not perfect.