Finding an Affordable Spare Tire Kit for Your 2018 Cadillac XT5

Many 2018 Cadillac XT5 owners are surprised to learn that Cadillac did not include a full-size spare tire as standard equipment. Instead, the vehicle comes with a compact space-saver spare, and some models may lack even that. This reality has driven resourceful owners to hunt for aftermarket and used spare tire options on platforms like eBay and Facebook Marketplace. With the right knowledge, you can assemble a complete spare kit for a fraction of retail pricing.

Understanding XT5 Spare Tire Compatibility

The 2018 XT5 Platinum typically comes equipped with 235/55R20 tires on 20-inch wheels. For spare tire purposes, an 18-inch wheel is the industry standard for most GM SUVs, including the XT5. The compatible specifications are:

Wheel size: 18×4.5 inches
Bolt pattern: 6x120mm (GM standard)
Tire size: T135/70R18, 165/90R18, or similar temporary spare designation
Load capacity: Designed for temporary use only, not sustained driving

The GM 18-inch spare wheel (OEM part 84046085) is widely available as an aftermarket option and will physically bolt onto your XT5.

Critical Brake Clearance Considerations

Before purchasing an 18-inch spare wheel, owners with 20-inch factory wheels need to be aware of a critical fitment issue: the compact 18-inch wheel has a smaller barrel diameter than full-size wheels and may not clear the larger front brake calipers on the XT5 Platinum trim. This is especially true if your vehicle is equipped with performance or upgraded brake packages.

If you experience a front-tire blowout, the safe approach is to move a full-size rear wheel to the front axle and install the compact 18-inch spare on the rear, where brake calipers are typically smaller. Always carry the jack and wrench necessary to swap wheels, and verify the spare fits before you need it roadside.

Where to Find Used Spare Tires

Facebook Marketplace and eBay remain the most affordable places to source XT5 spare wheels and tires. As reported by many owners, prices range from $25–$75 for a used wheel-and-tire combo, though shipping costs can substantially increase the final price. A recent example: a seller in Kentucky listed an 18-inch Chevy spare for $25 with ground shipping running approximately $80.

When shopping used tires online, follow these best practices:

Check the DOT date code on the tire sidewall (four digits representing week and year of manufacture). Avoid tires older than five years.
Inspect tread depth using a penny or gauge tool. Temporary spares should have at least 4/32 inches of tread.
Ask the seller for photos of the wheel for rust, cracks, or damage, and the tire for uneven wear patterns.
Pay with a credit card rather than cash or wire transfer for buyer protection.
Factor in shipping costs and sales tax when comparing prices to retail kits.

Scissor Jack and Tool Kits

A 2-ton scissor jack is suitable for most mid-size SUVs and typically costs $15–$30 at Harbor Freight, Walmart, or Amazon. A 2-ton jack has a 4,000-pound load capacity, which is adequate for an XT5 that weighs approximately 3,600–3,900 pounds. Key features to verify:

Lifting range of 4–15 inches (standard for scissor jacks)
Stable, oversized base (at least 15×4 inches) for roadside safety
Included ratchet handle and speed wrench to avoid hand-crank fatigue
Anti-rust coating for durability in storage

Consider upgrading to a complete kit that includes a lug wrench or 4-way wrench. Many roadside tire changes fail not because the jack is inadequate, but because the lug wrench alone cannot break loose stubborn lug nuts. A ratcheting breaker bar or 4-way cross-wrench gives you significantly more leverage.

Aftermarket Kit Options

If sourcing used parts feels too risky, several companies offer complete 2016–2026 XT5 spare tire kits at retail prices ranging from $80–$250. These typically include:

One pre-mounted 18-inch wheel and tire assembly
A 2–4-ton scissor jack with vehicle-specific saddle
Lug wrench and ratchet handle
Carrying case or bag for storage
Warranty and customer support

Popular retailers include Modern Spare, Value Spare, and SpareTire.com. Kits purchased from established retailers are DOT-certified, properly balanced, and come with manufacturer documentation—a valuable assurance if you need to make a warranty claim.

Storage and Maintenance

Once you’ve assembled your spare kit, store it in a dry, cool location such as under the rear cargo cover, in a plastic storage bin, or in a garage. Keep the spare tire inflated to its rated pressure (check the sidewall marking) and inspect it quarterly. Temporary spares lose pressure over time, and a flat spare is useless in an emergency.

Before hitting the road for a long trip, test-fit the spare on your XT5 to confirm clearance and compatibility. There is nothing worse than discovering fitment issues during a roadside crisis.

The Bottom Line

Building a complete spare tire kit for your 2018 XT5 Platinum does not require spending $200–$300. By shopping locally and online marketplaces, exercising caution with used parts, and picking up an affordable scissor jack at a discount tool retailer, you can assemble a functional, safe emergency spare for under $100. Just be certain to verify brake clearance, check tire age and condition, and test the fit before your first long drive.

Finding an Affordable Spare Tire Kit for Your 2018 Cadillac XT5