Buger

We shamed Sheylen into changing his avatar. :D :D :D

sheylen

What change? It is a bug!!!! :p

wakeech

hey, i KNOW i saw a pic of the orange Z Concept in there last night... :D

R.Cade

unless you look at it with logic and don't increase the width and overall diameter, as in your examples


Dunlop SP Sport 9000
245/45-16 weights 25.1 lbs
245/40-18 weights 24.8 lbs

If the width and overall diameter are the same, then just the HOLE in the 18 is bigger, making it lighter then the 16. Not in every case I know, depends on how the tire is made.

And considering a high quality rim can weight only 17-24 lbs, and almost all tires weight around 25 lbs , most of the weight CAN be in the tire. gasp! So trading rim for rubber is not always that bad. It has nothing to do with density of material really :P

Of course there are 18 inch rims that weight over 30 lbs, but if Mazda put some thought into the design, the 18's can perform AND look good. Oh did I mention the benifits in performce of a smaller sidewall due to less flex?

Sputnik

And that's for the heavy 17 and 18 inch rims, not necessarilly the "quality" ones.

---jps

zoom44

looks like a bug to me:D :p

SmokingClutch

It's very simple why, really.

In car design, it has been shown that a given ratio of wheelbase to wheel diameter is most pleasing to the eye.

This is why so many people like the look of an SUV or large sedan with large diameter wheels.

The RX-8 has a fairly long wheelbase for a car of its type - to make up for this long wheelbase visually requires larger diameter wheels. Smaller wheels with higher profile tires don't work because the eye is not drawn to the rubber, it is drawn to the metal - the "bling" effect.

Furthermore, larger wheels help to visually fill large wheel openings, which are quite in vogue these days and very evident on the RX-8.

Wait til you see an 8 with the 16" base wheels. You'll cringe.

ZoomZoom

That’s good because I thought that my eyes were going when WankelWannabe thought it was an Audi TT.

sheylen

Z350, TT, bug... I apologise profusely. Anyway they all look the same:D . After 100 posts its is time for a decent avatar.

regards,

Vaillant

Well, the weight of the two may be the same, so for unsprung weight, you wouldn't have to worry. However for rotational inertia, where the weight is matters. It's a function of the radius, meaning that having the same weight tire further from the center of the rim increases the inertia. Plus, you've got part of the rim further out as well. More rotational inertia means it's harder to start and harder to stop.

I think Mazda is going to do the right thing as far as the wheel weight of the 18's go. With the Miata, for example, they tend to put on quite light wheels. I would rather have 17's, though.

Weight is the enemy!

WankelWannabe

Even my girlfriend, who knows very little about cars, thought that the 350Z was "one of those Audi TT things" when she first saw one on the road.
:p