This is for everyone having a big deal with my chrome wheel 20's. I just sold my OEMs. As I was shipping them out I recognized that ....
1. The stock 225/45/18 Dunlops weigh 24lbs
2. The stock RX8 18" rim weighs i believe 21 lbs
3. The stock rim+tire diameter is 26 inches
So... 26" diameter 45lbs total wheel weight and thats without air...

1. 20 inch rims w/tires weigh exactly 50 pounds (with air)
2. 26" diameter with 35 tires.

So the wheels must weigh nearly the same, so then I ask Whats The Big Deal?
I plan getting 20" RE30's in formula silver or F1 black chrome, and if not those, then GT30 2 piece. And Im sure weight wont be a problem.

 

inertia

 

If you want 20 inch chrome rims go for it amigo. I think some people have issue with it because it is something that you usually put on more of a luxury car, cruiser, or SUV, not a sports car. Me personally, I have never really liked the looks of chrome wheels.

 

what about inertia if friction is about the same for these two wheels? Describe it to me, what you mean, because Inertia by itself explains nothing.

 

F=ma

 

Ok, I can understand the attack on "chrome", as it may be for more of a luxury car, cruiser or SUV. However nowadays a lot of cars are going VIP, and put chrome 20's on Lexus, S2k, G35, G37s, a lot more imports! Then someone came up with the comment "chrome is too heavy and not for racing", RETARD I said, "VOLKS, ADVANS, RAYS, WORKS, all make Chrome Racing rims from 17"-20", i.e. GT30s, RE30s? Lets just say they if they were 20" all black gloss Volks RE30s would people still have an issue with them being 20's because they are black and not chrome?

 

Two objects within the same gravitational field will experience the same acceleration, however, the object with a smaller passive gravitational mass will experience a smaller force (less weight) than the object with a larger passive gravitational mass.

The interesting thing is that, physically, no difference has been found between gravitational and inertial mass.

GOOGLE. BTW.

 

inertia= 1/2 mass * radius ^2

F=ma

in other words, you accelerate slower.

pwn'd?

 

Im no science major, and know this.... same weight, same diamter, same width, SAME

 

I think he is trying to say the mass is "almost" the same and the radius is the same, so what's your point with those equations? edit: I know why I don't want 20" chrome wheels. double edit: slow internet ftl

 

how is the radius the same? a 20 inch rim has a 10 inch radius. an 18 inch rim has a 9 inch radius. the tires don't count. those low profile tires are another matter altogether.

 

^all i know is this...for a 1-3 lbs loss per wheel is sometimes not worth buying $2-3k wheels, unless of couse you are planning to buy them for the looks, like myself, then go ahead. Im turing more to VIP styling now. Those are my Plans before SS12.

 

The wheel and tire together = 26" diameter and 13" radius in both cases.

 

look again, i said diameter, weight, width is the same. never the radius, even if we talk radius of the rim what does the tire do?? Doesnt it spin along with the wheel? Total Diamter, width, weight size is what matters when you are talking speedometer differences or acceleration differences.

 

I'm in no way a person to turn to for advice on a car but from what I can presume the less tire after a certain point becomes a determent. Let’s use a different vehicle for example, say my 79 Jeep CJ-5. Let’s assume that the complete tire/wheel size is 30” and work from there. With a 18” rim we have some good amount of sidewall that adds a lot of lateral flex. On a 26” rim we have far less sidewall and flex. We also have less impact room for road debris using the larger rim. In a jeep (I would hope) the goal is not so much cornering as for offroading. So the smaller rim with more room to play in the sidewall is an advantage. Too little sidewall and the jeep is pretty much useless offroad.

Now I see this on a smaller scale with the 8. We want less play on the lateral flex of a sidewall so we can feel connected to the road. Too much play and we may as well be driving the jeep through a corner. However, too little sidewall and you lose some of the flex needed to keep the tire in contact with the road. We’d just depend on the tread and compound alone to keep the contact.

Now, as I said, I’m far from an expert but I think we can figure that tires with the same width, weight and diameter should take the same energy to move. From a performance standpoint though, as far as handling, the size of wheel to tire combination makes a difference. Some may actually like a 20” rim over the 18” while others will not.

From a visual perspective it’s all taste. I’m personally not fond of the look of huge rims. I actually thought the stocks were a bit overkill to begin with but they grew on me. I think you are running into more of this than actual performance bias. I’m sure I’ll be corrected shortly though :lol

Anyway, what does it matter as long as you like the look of your car and how it performs?

 

edited

 

18inch OEM wheel+ 8inch 45 tire (4 inch rubber on top and 4 on bottom) = 26 diamter

20inch wheel+ 6 inch 35 tire (3 inch rubber on top and 3 on bottom) = 26 diameter.

 

How in the world do the tires not matter lol? Newton's laws don't care if the mass is rubber, aluminum, or kryptonite.

 

i care.

 

You are seriously going to quit with that remark? lol

 

The Lamborghini Countach had the widest rear tyres of it's time at a humongous 345/35R15. A low 35 Series profile was, let's just say, exotic!

Later on a lot of supercar manufacturers followed suit.
Some examples include the:
McLaren F1 with 315/45ZR17
Ferrari F50 with 335/30ZR18
Jaguar XJ220 with 345/35ZR18

Notice that these are all Z rated (150mph+) rated tires. I am running Nitto Neo-Gens (TOYO makes Nitto) 35ZR20. The lower the series profile the more reinforced the sidewall would be i would say, or why would they be more expensive for less tire?
385/15ZR22 ECTAS hold the fastest production tire record speed at 225mph+ a 15 profile tire on a PORSCHE (dunno what model) at Nurburing test facility.

Im going to say it depends on the rating of the tire. And how you said, I think it all depends on what sport (drag, circuit/track, drift, etc.) you are going to be participating in where tire/wheel/tire compound/tire rating combination comes into play...dont you?

 

rollin on dubzzz

 

Fencig is right about handling and sidewall height, but wheel diameter does matter on straight line performance too.

 

wtf?^THREADCRAP

edit: i agree j8635621 (why so many numbers?)

 

With Width you add another dimension. If you went with a wider tire you could offset the loss of sidewall flex with sheer contact area. Hence my point of relying on contact and compound after a certain point. I was just trying to keep that dimension out of the picture for now. However, as you also said, it really depends on what you want to do and how the driver wants to do it.

Also to your question on price for lower profile. Yes I imagine they have to make it sturdier but that takes in trade the flex that is needed when making a high lateral g turn.