YL06GS

Decided to go with the Antera 343's because they looked similar to the GS4 wheel. Wanted to have a factory look, but a lot bolder. They make the wheel in a full chrome also.

NeverSatisfied

Beautiful! Must be nice to have tons of wheel shops at your fingertips!?!

Neo

iTrader: (3)

Thanks for confirming my train of thought. I personally won't touch 20s on the 3GS until some major players have produced lowering alternatives. Again, that's just me.

Cadd

Nice!

However I also think it needs a drop....NOT because of too many finger gaps. To me it looks like you have a 2 finger gap, which is fine.....I don't mind that at all (although some members frown upon that.....some think anything over 1 finger is too much already). I have the same finger gap with my 17s. But what REALLY makes it look weird (maybe just in pictures) is the way it looks like an SUV now.

Why? Well, I looked at the pics real carefully, and if you use your hand to cover the top part of the car (from the hood up), it looks like a mini-SUV. Look at the ground clearance. For some reason (camera angle?), it looks like you have A LOT of ground clearance.

Although I have 2-3 finger gaps, my car looks like it is pretty close to the ground.

But you could care less! You're the first person to put wheels on the 3rd gen GS here on CL.

Neo

iTrader: (3)

That's because he went way over spec for the tires. The OEM tires are 245/40/18 which gives the outside diameter of 25.7. This is the same as the 2GS wheels.

The typical tire sizes for staggered 20s on a 2GS are 245/35 (OD = 26.8) and 275/30 (OD = 26.5). This is already 1" out of spec and there were rub issues.

His new sizes gives 27" front and 27.6" rear. The rear is almost 2" bigger than OEM. This is the only thing keeping the gap "small" but it will add almost an inch to the rear ground clearance.


YL06GS,

Did you intend to go this much out of spec? Your speedo is now about 7% off.

YL06GS

Neo-How did you figure this out? It is interesting to here this now. I have been asking around all week about 20's and this is the first I heard of calculations.

Cadd-Thanks for the input. That's why I posted it.

With the specs on the tires being off, I am not sure if I will be able to lower it now????

I can tell you this. These pictures don't even do justice to how good it looks. Gave the car the bold look and stance it needed.

Neo

iTrader: (3)

Are you talking about the outside diameter calculations? The diameter is basically

outside diameter = OD = rim size + (2 * sidewall height)

sidewall height = tire width (mm) * tire series / 100 * inch-to-mm conversion
tire series is a percentage so that is why it is divided by 100
1 inch = 25.4mm

So, for example, your new front tire is 255/35/20, Plug it in you get

sidewall = 255 * 35 / 100 * (1/25.4) = 3.51"
OD = 20 + (2 * 3.51) = 20 + 7.02 = 27.02"

For some reason, I must have missed your inquiry into 20s. Many of us run 20s on our 2GS (including me) so we could have given you more info. Did you have a thread asking about tire sizes?

YL06GS

Neo-With your experience do you feel the tire choice is a mistake. Everything you said makes sense. If the Previous GS and the New are the same, do you feel I should change to;

245/35-20 front
275/30-20 rear


Is there more than just possible rubbing issues?

Thanks

Cadd

Neo, WOW! You should give a "Tire sizing 101" class.

I understood you completely. However, for those who aren't really knowledgable in tires, your thread was tire calculations from hell! It looks damn confusing.

But Neo is dead on with the calculations!

YL06GS, here's a cheat sheet. Enter the OEM tire sizes on the left and enter your the size of your 20s on the right. Then scroll down and look at the overall diameter. Look at the difference. It will tell you that you are out of spec 7.2%. That means when your speedometer shows 60MPH, you're really going 64.3MPH.

http://www.miata.net/garage/tirecalc.html

Just becareful out there. If you're like most people you probably follow the +10MPH rule. If the speed limit is 65MPH, I'll normally go 70 - 75MPH (I don't want a speeding ticket).

Just say, you're going 75MPH (this is what your speedometer tells you) in a 65MPH zone. Well, guess what? You're actually GOING 80.4MPH! When the officer pulls you over telling you that he clocked you at 80MPH, you'll tell him that you were going only 75MPH......but I guess you can explain to him that you just got new wheels and they are much larger than OEM and it misled you. I guess if he's nice, he'll give you a warning and let you go.

EDIT: A better tire size (assuming you want to keep 255mm up front & 275mm in the rear) are:
255/30-20 (OD of 26" - only about 1% too large)
275/25-20 (OD of 25.4" - only about 1% too small)

But I don't know how easy/expensive it is to get 25 profile tires (does anyone make them????).

Cadd

Tire size is not the most important thing when you're looking into lowering it. Wheel offset is more important! If your offsets are too aggressive (making the wheels stick out a little too much), it doesn't matter if you have the correct spec tires or not.....they will still rub regardless.

Does anyone know if the 3rd gen OEM wheels are real conservative (like the 2nd gen where both the front & the rear wheels are ALL THE WAY in the car?). I'm just curious, what are the offsets of the 3rd gen wheels?

CaMsGS3

YLO6: looks good, would look 10x better if dropped though

NEO: on a 06 GS what the biggest profile tire it can fit in 20s
I know now that on the gen2 GS all 20's are not the stock diameter, no matter what tire size you use, correct?

I figured since the gen3 GS are made for 18's stock, i figured it would have a 40 profile tire [non staggered] without affecting the speedo & diameter while on 20's.......i was hoping that lexus would make the gen3 GS ride a little more comfortable on 20's

Neo

iTrader: (3)

These are the typical sizes to put on 20s for the GS. This will bring you closer to spec but it will still be larger than spec. It depends on how the current setup feels on the car and if you are willing to spend more money to replace tires. From a functional point of view, I personally would prefer the 245/35-275/30 combo but from a practical point of view, it is harder to call. It depends on your tolerance of the size, odometer, and speedometer being off.

It is too hard to call on long term effects of the additional size and weight on the suspension and brakes. But this would be the case with 20s with the "correct" tires too. There is also the lowering issue too.

Sorry I can't give you a definite answer. I can only relay what has been done in the past with goof success. Good luck on your decision.




At this point, it is hard to tell what rim setup (width/offset) would be optimal on th 3GS. Overall diameter size, however, is the same. The 18s that are on the 3GS use 245/40 tires. This is the same sizes that are already being used on the 2GS (aftermarket). The "correct" size (non-staggered) for both the 2GS and 3GS would be 245/30. The problem is that this size is harder to find and the ride quality would be even worse. These are the two main reasons why GS with 20s are out of spec.

NYlexus

YL06GS,

Hay man loving the car there ...I have a 1999 Black GS300 with tan interior. the only mod i have now is CATZ XENON, YELLOW FOGS and a kenwood kvt911 dvd system with 2-6.5" headrest screens...after looking at ur car , i really gotta rim this car up ....I dont about you but my next car wil be silver because the black color attracts dirt and dust and it really pisses me of after washing.

Sorry to go off topic but i see that u are in the Yorba linda Area...I am sure that I will see your car around becuase my office is in Savi Ranch..luv to see your car with 20's on the road or stuck in 91 trafiic. lol


laterz.

YL06GS

NYlexus-Keep your eyes out! Was at Wahoos last week. Always up and down YL Blvd. Trying to stay off 91, too sandy! You'll have to look out for flipside909 there.

verone

big props love it