What are the wheel specifications for the CT4?

[DelPenelope]

ct4 wheel size is 17 inches, with a bolt pattern of 5×115mm and a single weight of approximately 11 kg. Here is a detailed introduction to car wheels: Function: The main function of wheels is to influence the size of brake specifications and the selection of tire specifications. Larger wheels can accommodate larger brake systems, and wider wheels can use higher-performance wide tires. Composition: Car wheels refer to the components used to bear the rigid rotational inertia between the car and the tires, and can also be called rims or steel rings. A complete wheel unit includes car bearings, also known as flanges, which support the wheels in conjunction with the tires.

[OwenRose]

I've been driving the CT4 for three years and have thoroughly understood the wheel specifications. The bolt pattern is 5×115 mm, meaning five bolts are arranged in a 115 mm diameter circle. The center bore is 70.3 mm, which I specifically measured when I last changed the wheels. The original offset ET value ranges between 42 to 45 mm, fitting perfectly flush with the wheel arches when mounted. There are two tire sizes: 17-inch wheels have a width of 8J, paired with 225-width tires; the 18-inch ones are upgraded to 8.5J, accommodating 235-width tires. Last year, when helping a fellow car enthusiast upgrade to 19-inch wheels, I found that even a 1 mm deviation in the bolt pattern wouldn't work, and the center bore required hub-centric rings to prevent shaking at high speeds. Changing the ET value must be done carefully—exceeding ±5 mm will cause rubbing against the suspension springs.

[George]

Having worked in car modification for seven years, I can recite the CT4 wheel specs with my eyes closed. The bolt pattern is 5x115mm, and the center bore is 70.3mm—a common specification among many GM models. The offset fluctuates between 42 and 45; it's recommended not to exceed this range when changing wheels. The stock 17-inch wheels are 8 inches wide, while the 18-inch ones are 8.5 inches wide. Just worked on one the day before yesterday and found that if the new wheel's center bore is larger than 70.3mm, you'll need hub centric rings, otherwise the steering wheel will shake badly. Remember to torque the wheel bolts to 140 Nm as per the service manual—too loose or too tight can damage the bearings. If you're looking to upgrade the size, 19-inch wheels with 245 tires are the limit; anything larger will rub against the fender liners.

[WilliamLee]

Just checked the repair manual last week, the CT4's standard wheel specs are clearly outlined. The bolt pattern is 5×115mm, with a center bore of 70.3mm—common dimensions for GM vehicles. The offset (ET value) has a ±3mm tolerance, with factory wheels falling within the 42-45mm range. Base models come with 17×8J wheels paired with 225/45R17 tires, while higher trims feature 18×8.5J wheels with 235/40R18 tires. The J-value is stamped on the inner wheel barrel—when replacing, ensure the new wheel's center bore diameter isn't smaller than 70.3mm to avoid hub interference. Rear track width is approximately 10mm wider than the front, a factor to consider during wheel swaps. Maintaining OEM ET values is recommended to prevent unnecessary steering system stress.

[GriffinFitz]

With three years of experience in modifying CT4 wheels, actual measurements are paramount. Verified over a dozen times with a tape measure: bolt pattern is definitely 5×115, center bore is precisely 70.3. Factory offset is most commonly 43mm - when adjusting ET value, remember to calculate wheel protrusion: every 5mm reduction in ET moves the wheel outward by half a finger's width. 17" wheels measure 431mm actual diameter, increasing to 457mm for 18". For upgrades, 19×8.5J is the safest choice, pairing perfectly with 245 tire width to avoid fender rubbing. Use M14×1.5 bolts with 60-degree conical seats for secure fitment. Post-installation wheel balancing is mandatory - even 10g of imbalance weight difference causes highway vibration.

[VanKyle]

When I first bought a car, I was also confused about wheel parameters, but now I've got it all figured out. The CT4 has five bolt holes forming a circle with a diameter of 115mm, and the hole in the center of the wheel hub is 70.3mm wide. The higher the ET value, the more concave the wheel is, with the factory setting around 44mm. The distance from the edge of a 17-inch wheel to the bolt surface is 125mm, and 135mm for an 18-inch one. Once when changing tires, I noticed '7.5J' engraved on the back of the wheel, which simply means it's 7.5 inches wide. If you're planning to change wheels, first check your tire size label: for example, the '18' in P235/40R18 indicates the wheel diameter. Spare tire wheel data is different, so don't mix them up.