SC40096 Posted June 26, 2004 Share Posted June 26, 2004 I'm in the market to buy new Rims and tires. I really want a staggered fitment but I don't want to jeopardize the anti-lock brakes, treadwear, Camber, Speedometer etc. Would some of you please post what you got installed in your SC? Quote Link to comment Share on other sites More sharing options...
JDOwen2 Posted June 26, 2004 Share Posted June 26, 2004 I've got IS300 17" w/245/55/17" Predators. Nice ride quality. Quote Link to comment Share on other sites More sharing options...
bean_8044 Posted June 26, 2004 Share Posted June 26, 2004 If you install larger rims, it wont affect your ABS. At least it shouldnt. Camber shouldnt be affected also as it would be corrected through an alignment. As far as the speedometer, you just have to get a tire/rim combination thats close to the original size. I.E. -stock 15s with monster tires = 18s and low profile. Not exact, but you get the idea. If you go to any tire store theyll be able to tell you the exact size you can go up to. Even being a little over or under doesnt hurt much. The speedo may be off by two or three mph. Your tread quality totally depends on the tires you get and how you drive your car. More expensive does not mean better tread wear either. Quote Link to comment Share on other sites More sharing options...
Theodore Posted June 27, 2004 Share Posted June 27, 2004 Intellextual This has been copy and pasted from this web site. You should print this out answers alot of questions. WHEELS & TIRES: When shopping for new wheels, take note of the wheel diameter, wheel width, bolt pattern, and wheel offset. Both SC coupes' bolt patterns are 114.3 x 5, stud design, with 12 x 1.5 threading and 60.1 bore. The stock offsets are +50mm. With larger and wider wheels some rubbing may occur on the fender lip or wheel well covers. This rubbing usually occurs when turning the front wheels all the way out or when the suspension bottoms out. Rubbing is attributed to several factors including: the drop height of the suspension, size of the tire sidewall, tire & wheel widths, and the wheel offset. The simple way of resolving a rubbing issue is by softly rolling the fender lip into a sharp wedge or shaving/lifting the wheel well covers where the rubbing occurs. The largest wheel size that fits the SC wheel wells are 20"x9" in the front and 20"x10" in the rear. 19" wheels and below will fit the SC without rubbing issues in any assortment of wheel widths under 10 inches given the proper offset and tires. The widest tires ever attempted on the SC coupe are 275/30-ZR20 on a 20"x10" rim, 295/30ZR19 on a 19x11" rim, 295/35-ZR18 on an 18"x11" rim, and 315/35-ZR17 on a 17"x9.5" rim. All fitments were reported to work on the rear axles with no rubbing issues. Below is a chart of tire sizes that are compatible with the SC and offer the similar outside diameters. Outside diameter is critial to maintain for the proper functioning of the anti-lock brakes, speedometer, and odometer instruments. These are just some of the tire sizes that fellow ClubLexus members are using on their cars. Some values are expressed as ranges of sizes. No size advertised below guarantees a perfect outside diameter match, it is recommended that you perform outside diameter calculations to ensure the tire is a good match. See more details below the chart... So let's shop for new tires for our new 17x9.5" Supra TT wheels. To calculate the outside diameter of a potential tire, 255/45ZR17 for example, you take the tire width (ie: 255mm), multiplied by the sidewall series given in a percentage (ie: 45% or 0.45), multiplied by two sidewalls per wheel, plus the diameter of the wheel in a common length (ie: 17-inches or 431.8mm). So you get [ 2 × (255mm × 0.45) ] + 431.8mm = 661.3mm outside diameter. Doing the same calculations for the stock 225/55ZR16 tires, we find that the stock outside is 653.9mm. 653.9mm is the value by which all the components operate. We can find the deviation from stock of our new Supra tires by dividing the new outside diameter by the old outside diameter. 661.3mm ÷ 653.9mm = 1.0113% or 1.13% deviation. Thus when your speedometer reads 60.0mph, you are actually travelling at a speed of 60.7mph. A better tire fitment would be 245/45ZR17 which, using the same formula, yields an outside diameter of 652.3mm. 652.3 ÷ 653.9 = 0.9975%, which is about 0.2% deviation. When your speedometer reads 60.0mph, you are now actually travelling 59.99mph, which is an acceptable difference. Now that you understand the principles, click here for a quick tool that calculates it for you! Spacers: Another available mod for your wheels are wheel spacers. These are used to compensate for negative wheel offset. For instance, the SC coupe's stock offset is +50mm; However, Supra TT wheels have +38mm offset. Therefore you can use 5mm - 15mm spacers to correct the difference and line up your wheels better. It is strongly recommend you avoid 'universal spacers' in larger sizes than 5mm; However, there are some larger aftermarket spacers that are tested to work well with the SC300 and SC400. H&R Springs makes wheel spacers designed for the SC coupe, which come with longer replacement wheel studs. H&R spacers come in the following thicknesses: 5mm, 15mm, 20mm, and 25mm. H&R 5mm spacers to not included lengthened studs because they are not necessary. With any spacer wider than 5mm, it is recommended that you use lengthened wheel studs. Quote Link to comment Share on other sites More sharing options...
blueviol Posted June 28, 2004 Share Posted June 28, 2004 A better tire fitment would be 245/45ZR17 which, using the same formula, yields an outside diameter of 652.3mm. 652.3 ÷ 653.9 = 0.9975%, which is about 0.2% deviation Good information. It is not 0.9975% however.^^ According to the formula, 245 40ZR18 tires are the closest fitment resulting a 653.2mm outside diameter, 0.9989 = 99.89% close to the original stock. Quote Link to comment Share on other sites More sharing options...
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