Addiction2

Gang,

There are many things about tires and wheels I don't know and I think I'm not alone so I'm starting this thread as an education thread with a post I'm copying from another thread.

Explanation of the numbers on your tires:

245/40/19 is our example.

245, 275, that's the WIDTH of the tires in mm. so 245 means a tire that's 245mm wide.

the second number is the sidewall height, which is a % of the width.

the third number is the diameter of the RIM that the tire will fit on.

so for example, 245/40/18, that means the tire is 245mm wide, the sidewall is 245 x 0.40 = 98mm, and it's for 18" wheels. if you add everything together, i think the overall diameter of the wheel will be around 26"

now say you go to 19" wheel, you need 245/35/19. that means the tire is still 245mm wide, but the sidewall is not 245 x 0.35 = 85.75mm (instead of 98mm), and it's for 19" wheel. if you add everything together, the overall diameter is around 26" again

the goal is to have the overall diameter of the wheel being about the same as stock, that way the speedo will not be off. so just another example, if you get 20" wheel, the tire will be 245/30/20, if you want to stay with the same overall diameter

and 275/30/19 is not a missprint. that's a tire of 275mm width (much wider than 245), and the sidewall ratio is 30% (instead of 35%). since the tire is wider, although the % is lower, but if you do the math, the sidewall height will be very similar to that of the 245/35/19. try to do it, you will understand

and as long as you get wheels that's of the right offset, width, and also get tires of the right spec, you are good to go.

Addiction2

Now can someone be kind enough to explain offset and reverse lip?

rominl

iTrader: (4)

thread like these are good. i will probably keep them here for now, over time i will probably move them over to the tires/wheels forum, which is more generic

regarding your second question on lip. a lot of aftermarket wheels they have lips right? there are two type, stepped and reverse.

the reverse lip is probably the "normal" lip setup most people have seen so far. it's just a big flat lip. so someone says he got a 4" reverse lip in the back, then you will see a flat 4" wide lip. that's easy

stepped is the other kind of setup. which is, instead of a flat lip, there is actually a step in between. the part of the lip that's closer to the center face of the wheel, it's a bit higher than the outside, creating a "step" look.

that's the difference between the two.

for the definition of offset and so, read my sticky thread here:
https://www.clublexus.com/forums/sho...d.php?t=175288

when i have enough information on the sc430 setup, i will probably add that to the content as well

Neo

iTrader: (3)

Step/Normal lip:


No Step/Reverse lip:

rominl

iTrader: (4)

thanks for the pics neo, i knew you would jump in with pics

Addiction2

more questions, guess I'm the only one who needs this education:

- When I see 20x8.5 I know what the 20 means, what does the 8.5 mean?
- I see a lot of cars that have 20x8.5 in the front run 20x10 in the back why?
- Is there a benifit to a multi-piece wheel?
- I typically don't get chrome wheels because I hear they require much more care and in areas where there is snow the salt will do real damage to them. Is this true?

Neo

iTrader: (3)

As you already know, 20 is the diameter of the rim face. There is also a depth part of the rim (or if a rim is a cylinder, then the face is the circular part and the "depth" is the height of the cylinder). The second part of the spec (8.5 in your example) is the measurement of this depth. Actually, edge to edge is a bit more than 8.5 but in any case, that is where the measurement is.

Looks and power transfer. You typically see this staggered setup on RWD cars. More contact patch in the rear means more grip which translates to better and consistent power to the ground. As for looks, the rear wheelwell tends to be deeper on our cars so with a wider wheel (not the face width/diameter), you can get the face of the wheel (along the plane of the rear axle) more flush with the fender. Many like this aggressive look.
The multi piece part of it helps in terms of damage control. For example, if you curb your lips, you can technically remove the lip and send it in for repair/replacement. In real-life, though, you usually take the whole wheel to the shop you trust and they handle everything. There are other things that typically come with multi-piece wheels, such as strength but it is not a "requirement" of something being "multi-piece". You can make crappy multi-piece rims but this is not the case with most good brands.
I don't have chrome or live in harsh winter conditions so I don't have a comment here on the damage. I just know seeing damaged peeling chrome is not pretty.

camillian

Here we go again!

So if you have different rim depths, say 9 in the front and 10 in the back is there a visual difference of where the rubber meets the rim or does the 275 instead of the 245 compensate for this?

Addiction2

So what are 5-6 decent can't go wrong brand of wheels? And are there any "certianly not those" brands of wheels that jump to mind?

Neo

iTrader: (3)

I am no sure what you are asking. (Just a terminology clarifiation. The so-called term depth I was using was to explain the difference between the face diameter, which can be seen as a width, and the width/depth. When we use wheel terminology, it is the "width".)

The width of a tire when mounted on a rim with a particular width can be visually different. Some will fit comfortably and some will seem flatter as the tire is stretched out. The latter is when a tire width is slimmer than the rim width.

What are you asking in terms of this "visual difference"?

camillian

Yes that's it.

So finally if the overall diameter of a rim and tire combined remains pretty much the same as stock (around 26" when upgrading from a 18" to a 19" or even 20" rim because tire height gets reduced. Why does it look like the 20" fills in the space more than the 18". (diameter not depth). I mean when standing back from the car at a side profile the gap around thIe wheel well looks filled up with the 20" as opposed to the 18" where it looks like you can fit atleast 4 fingers. Is this an illusion or are these cars just lowered?

I want to thank everyone for their patience.
Mario

hageuzai

This happens because when you upgrade the diameter, you usually also change the offset
and the wheel tend to come closer to the outside.
Factory wheels are tucked in when aggressive aftermarket setups sit very close to the fender
arch, I guess that is why the illusion happens.

Speaking about the benefit of a multi-piece wheel, another point would be that you can choose
from a wider range of variation.
3 piece wheels are composed of an outer rim, inner rim and center disk, usually wheel
manufacturers carry several size specs of each piece and you can combine these to get
the best setup for your specific vehicle.

The concern about salt and harsh weather is true.
But that is not a problem just for chrome wheels, it gives damage to any kind of finish.
I also hear problems when you clean your wheel with some kind of cleaner but it isnt rinsed
enough and the cleaner remains on the surface leaving a stain when it dries off.
I personally think that is the worst and ironic thing you could possibly do as to damage the
wheel when you meant to clean it.
So I'd say its not the color of wheel or where you live, its how much you care about the wheel

camillian

Wow I went to another shop like Rominl said.

This guy told me the Opera 2 PL by OZ in 19 and 20" are for Audi and mercedes fit only. The Opera 1 PL which only comes in 18" fit lexus.
That would be 18x 8 with +35 offset front and rear. I know the 18 x 8 is factory but what about the +35 offset. Is that also the same or does it come out a bit more?
Can I make these wheels work by going 245/40/18 in the front same as factory and maybe play with the numbers in the back. Say 265/35/18 and add some spacers to bring them out a bit. Can I go with a wider tire in the back if the rim depths are the same all around at 8"

These wheels are too good of a deal to pass up and they are alot nicer than the factory ones even though they are the same size?

Thanks,
Mario

JCtx

You're already pushing the tire limit with a 245 tire on an 8" wheel IMHO, so you'd have to stick to stock tire size. My sincere opinion is 'why bother'.
If you insist in size 18" for ride reasons, at least go wider on the rear. I'd also ask here if the offset is not problematic. One reason I don't like to fit my cars with aftermarket wheels is the additional offset (wheels pushed out to the corners). Car looks great, but the additional stress on the suspension might be a problem in the long run, and who knows if the warranty would cover such thing. Since I'm not into 'cheating', and putting back stock tires if something happens, I just stick to stock. Certainly wish our car was like BMWs (with sport package) from the factory; they fit perfect from the factory, and most wheel designs are great looking too.
JC

camillian

So at + 35 offset the rims will be pushed out alot more than stock? Even though they are Only 8" deep. What is stock offsett?