Brendon

iTrader: (1)

First of all, I've done as much searching as possible on google and on the old threads here on CL, and I'm still not satisfied with an answer so I figured I'll just start this topic. Right now I'm in the process of buying a new set of wheels+tires from Tire Rack (my horrible Michelin all-seasons from the previous owner have finally died).

My main goal is acceleration improvement. After doing weeks of research, I've decided to opt for a set of 225/50 17" Continental ExtremeContact DW summer tires. They Weigh just 21 lbs and have 100% positive reviews on Tire Rack. I was considering going wider, but since I'm not running a boosted engine, there's no real advantage.

My dilemma is over the rim width. There's a set of 17" rims that I'm interested in; however, they come in both 17x7" and 17x8". Both widths are on sale for the same price, and the difference in weight between the two is just 1 lbs. Continental approves these tires for 6-8" wide rims. What are the practical advantages of a wider rim? Does a wider rim affect things like MPG, cornering, or traction? Keep in mind, I'm not stretching the tires; I'm staying within the approved rim width. If there's no real advantage to going an inch wider, I'll go for the 17x7" since its lighter.

vrsc400

iTrader: (1)

The wider rim will give you a larger contact patch where the tire meets the pavement
but the improvement to acceleration will be negligible
there will be more power hitting the road but unless you have a very accurate timing system you probably wont notice much
the wider rims will look better though haha

FutureSC

iTrader: (1)

^ but he's going with the same tire width either way so the smaller width wheel will have the slight advantage because of weight. The only advantage of the wider rim would be the advantage of having a wider tire on there.

Also, since you would be going with the same tire for different width rims, the total diameter (tire and wheel put together) would be slightly different. Just something to think about.

Ali SC3

iTrader: (10)

wider rim will widen the contact patch for a given tire by a tad and more importantly it will move the total contact patch further away from the center of the car considering the wheels have the same offsets, you will notice even more if your new wheels have a lower offset than the stock 50 or 60mm cant remember. (most aftermarket for our cars start usually below 40 and there isn't a limit for the low)

If the added weight is not a concern for you then wider rims in the rear will help the handling characteristics of a rwd car by giving it a wider stance. obviously the more mass you are turning means you will loose out on acceleration, but chances are with 225's you will already be maxing out how much power you can put to the ground.

I would recommend at least 245's on the rear even on a stock car, now is your chance to get it right and trust me 245's are the minimum. My sc300 used to spin 225's like they were nothing. if you want max accleration get the least widest tire that your car struggles to spin out on. it will most likely be in the 245-255 range for an sc400.

IF I were you I would consider running 17x8 in the rear and 17x7 up front.
I would run a 245-255 in the rear and 225's up front. that would be a good balance and still get all your power to the ground without going too wide.

and for reference 245 isnt really that wide, It comes standard on a lot of lexus vehicles.
For some reason the SC got the worst of the worst when it came to wheels and tires.

5sp_jzz30

iTrader: (2)

get some real sized wheels and tires.

you are on stock power. whats the point of "maximum" acceleration? street racing a stock sc?

btw dont go with continental for anything. they cant make a good tire to save their life. i use continentals from audi's and MB as drift day burning material.

if you want a good summer tire then go with a:

toyo R1R
dunlop sp8000, sp9000, dz101, dz101 star spec
falken rt615, rk452
michelin pilot sport 2
bridgestone potenza re01r, re11, kdw(new kind), kdw2
yokohama advan ad08

also dont get pirelli's. only pirelli tire i have driven happily is the p-zero nero. p-zero corsa, asymetrico are crap. way over rated and over priced.

btw the above suggestions are all the tires i have personally tried for daily driving and drifting. my favorite street tires to date are falken rt615 and bridgestone potenza kdw.

OBEEWON

You have a 90's Lexus. Wider wheels look cooler. That's all that matters.

LiCelsior

iTrader: (32)

in the rain its not that fun. when i had 275 Supras on the rear of my LS, car felt squirrelly.

1JZPWRD

iTrader: (59)

I agree with the chosen width and tire name and model listed above.. Wider is always better.. More power to the ground, but sometimes weighs a tad bit more.. handling is also dramatically improved.

Brendon

iTrader: (1)

Does anyone know the weight of the stock SC400's 16x7" rim? I've tried searching and I get hits of everything from 20 lbs all the way to 40 lbs

ArodDaLob

iTrader: (14)

depends on if they have tires on it or not, probably why you're getting 40lbs vs 20lbs.
if looks isn't a factor, why go 17's? go with wider 16"s so you can get more than 225's on there (my daily driven tC even wears 225's). i'm not sure how much power you're pushing, but sometimes 225 just won't cut it.
and btw, my rpf1's weigh 35 lbs with tires, and they're 10" wide, so just keep in mind, there are wheels out there that'll be wider while slowing the car down less with less rotational mass.

sc4demon

iTrader: (2)

im pretty sure that the sc400 wheels are actually 16x7.5 just to let you guys know and the sc300 wheels are 16x7

Brendon

iTrader: (1)

http://www.lexus.com/contact/pdf/1992/1992SCspecs.pdf
http://www.lexus.com/contact/pdf/1997/1997SCspecs.pdf
http://www.lexus.com/contact/pdf/1998/1998SCspecs.pdf

Stock, the SC300 was 16x6.5" and the SC400 was 16x7". After 1998, they were all 16x6.5".

Ali SC3

iTrader: (10)

wow, those diagrams are pretty handy. i just changed the numbers for 1995 on the link and I got the one for my car.

sc4demon

iTrader: (2)

my bad i read on http://www.intellexual.net/faq.html that it was 16x7.5 for the sc400 but i guess they got it wrong

Pipe

Damn some cool stuff!! Oye Throw some wider wheels on her in the rear 9.5 or 10.