2018 Cadillac CTS Wheel Interchange

2018 Cadillac CTS Wheel Interchange and Fitment Guide

Known OEM Fitment For 2018 Cadillac CTS

The information below reflects verified data available for the 2018 Cadillac CTS. This model was offered with multiple factory wheel and tire packages. The wheel and tire entries provided here may come from different OEM packages. Always confirm what your specific trim and brake package uses by checking your driver door jamb tire placard, your owner manual, or OEM service information, then validate in the on-page calculator.

Notes:

• The listed 19 x 8.5 ET34 wheel and the 245/45R17 tire are from different factory configurations. Not all trims will clear 17 inch wheels. Verify your brake rotor and caliper size before using 17 inch wheels.
• If any specification you need is not listed or varies by trim, use the calculator on wheelinterchange.com and cross-check against OEM sources.

How To Use The Wheel Interchange Calculator

• Open the calculator and select your donor vehicle in Wheels from and your 2018 Cadillac CTS in Installed on.
• If you are testing aftermarket wheels, use Custom wheel size to enter rim diameter, rim width, and offset. You can also enter Custom tire size to compare overall diameter and sidewall changes.
• Changing rim diameter updates the tire diameter comparison. Keep the overall tire diameter close to your OEM package to protect ABS, traction control, and speedometer accuracy.
• Review inner clearance to the strut or knuckle and outer clearance to the fender and liners. Compare the new backspacing and poke to the OEM reference of 5.59 in backspacing for the listed 19 x 8.5 ET34 wheel.
• Check scrub radius changes by monitoring how much offset you add or subtract from the OEM ET34 baseline. Large jumps can affect steering feel and bearing load.
• When results look acceptable in the calculator, confirm physically before driving: test-fit one front and one rear wheel, rotate by hand, and inspect for interference.

Fitment Checklist Before You Buy

• Bolt pattern: 5x120 must match exactly.
• Center bore: 66.9 mm hub. If the wheel center bore is larger, use hub-centric rings sized 66.9 mm inner to your wheel’s outer bore. Do not use a wheel with a smaller bore unless it is professionally machined.
• Offset: Start from the known OEM ET34 for the 19 x 8.5 reference. Use the calculator to evaluate how moving offset in or out changes inner and outer clearance.
• Backspacing: Compare new backspacing to the 5.59 in OEM reference to understand inner clearance changes.
• Brake clearance: The CTS had multiple brake packages. Visually confirm spoke-to-caliper and barrel-to-caliper clearance. Some packages may not clear 17 inch wheels.
• Lug hardware: Thread is M14 x 1.5. Verify that the lug seat style on your wheel matches your lugs or nuts. Do not mix conical, ball, or mag seats.
• Tire overall diameter: Keep overall diameter close to your OEM package to avoid speedometer and ABS issues. Use the calculator to compare.
• Load and speed ratings: Tires and wheels must meet or exceed the OEM load index and speed rating listed on your door placard.
• TPMS: Plan to transfer, clone, or program sensors compatible with your CTS. Verify compatibility with your sensor vendor or OEM parts catalog.

Plus Sizing And Common Upgrades

Plus sizing changes wheel diameter and tire profile to maintain overall tire diameter while improving appearance or handling. General guidance:

• Use the OEM package for your trim as the baseline. The provided data includes a 19 x 8.5 ET34 wheel and a separate OEM tire size of 245/45R17 from another package. Confirm which your CTS actually uses.
• Aim to keep overall tire diameter within a small variance of your OEM package. Use the calculator to target a minimal difference.
• Maintain similar offset to control scrub radius and bearing load. Large offset changes can cause rubbing or premature wear.
• Staggered setups can affect rotation patterns and tire wear. Confirm rear clearance and load index if considering wider rears.
• Low-profile tires increase impact risk. Consider your road conditions and ride goals before stepping down in sidewall height.

Installation Tips

• Test fit first. Mount a front and rear wheel without tires where possible, or carefully check with tires for caliper and fender clearance. Spin by hand and compress the suspension if you can.
• Clean the hub face and the wheel mounting pad. Remove rust and debris to ensure the wheel seats flat and runs true.
• Use hub-centric rings if the wheel bore is larger than 66.9 mm. Ensure rings seat fully on the hub and in the wheel.
• Verify thread engagement. For M14 studs or bolts, ensure sufficient full turns of engagement. If using spacers, use longer hardware as required.
• Hand start all lugs, snug in a star pattern, then torque with a calibrated torque wrench to the value in your owner manual or OEM service information. Do not rely on impact tools for final torque.
• Re-torque after the first 50 to 100 miles of driving and after temperature cycles.
• TPMS: Transfer or install compatible sensors and perform relearn as specified by Cadillac. Follow the owner manual procedure or use a TPMS tool.

Tools And Helpful Supplies

• 1/2 inch drive torque wrench: Search on Amazon
• Wheel lug cleaning brush: Search on Amazon
• 3 ton jack stands: Search on Amazon
• Hub-centric rings 66.9 mm ID: Search on Amazon

FAQs

• What is the bolt pattern for the 2018 Cadillac CTS?

  5x120.

• What center bore does the CTS use?

  66.9 mm. If your new wheel bore is larger, use hub-centric rings sized 66.9 mm inner to your wheel’s outer bore.

• Which OEM wheel and tire sizes are correct for my CTS?

  The CTS was sold with multiple OEM packages. Data provided here includes a 19 x 8.5 ET34 wheel and, separately, a 245/45R17 tire size from another package. Check your driver door placard and owner manual, then validate in the wheelinterchange.com calculator.

• Will 17 inch wheels fit my CTS?

  The 245/45R17 size appears in OEM data for at least one package, but not all trims and brake packages will clear 17 inch wheels. Confirm caliper clearance physically and with the calculator before purchase.

• What lug nuts do I need?

  The thread is M14 x 1.5. The lug seat style must match your wheel. Verify whether your wheel requires conical, ball, or mag seats and use hardware designed for that seat type.

• What offset should I choose for aftermarket wheels?

  Use the known OEM ET34 on a 19 x 8.5 as your reference and compare your new offset in the calculator. Evaluate inner clearance to struts and outer clearance to fenders. Avoid large deviations without confirming clearance and handling effects.

• Do I need wheel spacers?

  Only if required for caliper or suspension clearance. Use hub-centric spacers with appropriate extended hardware and re-verify torque. Check that fender coverage remains legal in your area.

• How do I keep the speedometer accurate when changing sizes?

  Use the calculator to keep overall tire diameter close to your OEM package. Large differences can affect speedometer, ABS, and stability systems.

• What is the correct torque for the lug nuts?

  Do not guess. Consult your owner manual or OEM service information for the 2018 CTS and torque with a calibrated wrench. Re-torque after initial miles.

• Will my TPMS sensors work with new wheels?

  Yes if transferred or replaced with compatible sensors. Some sensors need programming or a relearn procedure. Follow Cadillac’s TPMS relearn steps or use a TPMS tool.