jmecbr900

I am shopping around for new aftermarket wheels and tires. I am narrowing it down to 18-19's. I think, please correct me, that the stock offset is around +42. If so, what would +47 offset do to the look of the car? I am debating between several diff wheels and most have some kind of polished lip, which is the look I want.

It would be great if someone could explain what the maximum/minimum offsets are for my GS400 and how it applies. For example, the higher the number the more "flintstones" look, the lower the number the tire doesn't fill the fender well.

Someone please advice because I want to order my wheels ASAP....

Thanks in advance.

GS4Will

stock is +50

GS: +37 to +50 is ok

SoCalSC4

Depends on the wheel width- a 20x9 +50 won't clear the suspension in the front. It's complicated...

jmecbr900

ok....let's get a little more detailed then....

If I go with say....18x7.5 all the way around with a +40 offsett all the way around....with some 245/40/18 tires on them??????

Will I look like a 4x4 on the stock springs and that tire/wheel combo? Will the wheels stick out of the fenders? Will I scrub with weight in the back?

Pardon the stupid questions, but I'm not familiar with the Lexus suspension geometry and don't want to make a big mistake ordering wheels that look good on the internet, but look like crap or don't work with my car.

Inochi3

if you were to go 18x7.5 all the way around with a +40 offset, i highly doubt you will be able to run 245/40 in the front without heavy modification to your fender, even then i don't think it's possible, i would go with 225/40 all the way around with a +40 offset

legendary

everything you need right here:
https://www.clublexus.com/forums/sho...threadid=62341

jmecbr900

Are you sure that a 245/40 will not work in the front? What's wrong with a +40 offset? Should I go with a different offset?

jmecbr900

I read the whole thing and there's nothing really about 18". Most of the info is about 19-20's. Thank you though.

legendary

well,what i meant is regarding the offsets....most guys put 19 or 20 inchers...the offset stands the same though as a reference

jmecbr900

Gotcha. I read that. It was a little confusing, but I called one of the vendors mentioned and he cleared it up. He suggested I go atleast 18x8 to look right.

Thanks for the info.

Inochi3

you can run 225 tires on a 7.5" wheel, i have 18x7.5 all the way around with 225/40, depending on the wheel you want, some manufacturers don't make certain widths like in my case, they only make 7.5 or 8.5 widths, if you really want it to look good, i would go with a staggered setup

mumbles

jmecbr900, they say a picture is worth a thousand words...




The offset of a wheel is the distance between the centerline of the wheel, and the hub mounting plate. So, say you increase the offset from +40 to +45, since the centerline stays in the same place, the hub has to move outward towards the street side of the wheel. By doing that, you have effectively moved the rest of the wheel closer to the suspension. Why? Well, picture the wheel sitting on the lugs, but you haven't put on the lug nuts yet. Now imagine if you could (without moving the rest of the wheel) pull the wheels hub plate outward a few millimeters (increasing the offset), you would then have to push the whole wheel inward to get the hub plate and the hub to meet up again. So, the larger the offset, the further the wheels will be pushed in under the wheel well. The smaller the offset, the closer they will be to the lip of the wheel well.

Another consideraton is disk fitment. This is the thickening or thinning of the wheels hub mounting plate to provide clearance for bigger or smaller disk brakes. Many people have upgraded their disk brakes to Brembos, AP Racing, Supra TT brakes, etc... Some of those calipers are pretty massive, the Supra's in particular, so you have to select a wheel with a "high(er) disk" option in order to clear the calipers. By thickening the hub mounting plate, you provide more clearance for the brakes, by thinning it, you provide less clearance. Typically, but not always, the front brake upgrades include much larger caliper that the rear brake upgrades, so you need to be more concerned with clearance in the front than the rear. The downside to a high disk wheel, is that you almost always get a smaller lip, or the center of the wheel bows outward... hey, they have to come up with the space somewhere

Last but not least, is diameter. When the manufacturer decides on wheel/tire size, the speedometer is calibrated to the overall diameter of this combination. You can increase the diameter of the wheel, but to keep the speedo synched, you have to choose a tire with the proper tire width/sidewall ratio which keeps the overall diameter the same. It won't be exact, but proper tire selection will keep the diameter within 1% or 2% of stock. I have found this site very usefull in determining tire sizes;
Miata.net tire calculator

I hope this isn't too basic, and helps somewhat. Also, since you are in Georgia, we have a CL meet the first Sunday of every month, you can get more info here...
SELOC forum

jmecbr900

Very helpful info mumbles. Especially the part about smaller vs. bigger offset and what it means. That is the bottom line exp. I was looking for. Thank you for the info.

According to your link, the speedo should remain very much "on" since the rev/mi are almost identical to stock.

Thank you for the education.

dipstick

kudos to Eric! I wondered what "high disc" and "low disc" meant.

mumbles

You are more than welcome! I noticed that you had already found out about the monthly meets, so hope to see you soon. I also see that you have met Nuum (VVT-i) already. He is truely one of the good guys!