Modified Cars and Extended Warranties: Lift Kits, Tunes and Wheels

Plenty of drivers like to personalize their cars and trucks. A lift kit, a performance tune or a set of larger wheels can change how a vehicle looks and drives, and also how a service contract treats a claim. Here is what to know before you modify a car you plan to cover, or cover a car that is already modified.

Why modifications matter to a service contract

A service contract is priced on the assumption that the car runs close to how the manufacturer designed it. Modifications can add stress to parts or change how they wear. Because of that, most contracts include an exclusion for damage caused by modifications or aftermarket parts.

The key word is usually "caused." In many contracts, a modification does not automatically void the whole plan. Instead, a claim may be denied if the administrator decides the modification caused or contributed to the failure. Some contracts are stricter and may limit eligibility for heavily modified vehicles. Read the specific language.

Lift kits and leveling kits

Raising a truck or SUV changes suspension and driveline angles. That can put extra strain on parts like:

• CV joints and axle shafts
• Ball joints, tie rods and other steering parts
• Wheel bearings
• Driveshafts and U-joints

If a CV axle fails on a lifted truck, an administrator may look at whether the lift changed the angle enough to cause it. A small leveling kit installed correctly may raise fewer questions than a large lift with oversized tires, but there is no universal rule. Suspension parts are often the first area affected.

Engine and transmission tunes

A tune changes software settings such as fuel delivery, ignition timing, boost pressure or shift points. Tunes can increase power, but they also raise heat and stress on internal parts.

Tunes are a common reason for denied engine, turbocharger and transmission claims. Some points to keep in mind:

1. Many tunes leave a record in the engine computer, even after a return to stock settings.
2. Administrators may ask the shop to check software versions during a diagnosis.
3. Returning the car to stock before a claim does not erase physical damage from extra stress.

If you plan to keep a tune, assume powertrain claims may get extra scrutiny.

Wheels, tires and other common changes

Larger wheels and tires change the effective gear ratio and can affect wheel bearings, brakes and speed sensor readings. Low-profile tires transmit more road shock. Again, the question is usually whether the change contributed to the failure.

Other modifications that often come up:

• Cold air intakes and aftermarket exhausts
• Aftermarket remote starters and alarm systems, which can affect electrical systems
• Lowering springs and coilovers
• Performance brake kits

Simple cosmetic changes, like window tint or a new stereo head unit installed properly, are less likely to matter for unrelated mechanical claims.

A note on federal law

The federal Magnuson-Moss Warranty Act generally says a manufacturer cannot void a factory warranty just because you used aftermarket parts. The manufacturer may still deny a specific claim if it shows the part caused the damage. Service contracts are a different product, and their terms are set by the contract and state law. Check your contract and your state's rules rather than assuming the same protections apply.

How to keep your coverage strong

If you want to modify a car and keep good coverage, a few habits help:

• Read the modifications exclusion before you buy a plan.
• Tell the seller about existing modifications and ask how they affect eligibility.
• Use quality parts and have them installed by a reputable shop.
• Keep receipts for parts and installation.
• Keep up with maintenance, which matters even more on a modified vehicle.

You can also browse our covered components pages to see which systems a plan might cover and where modifications tend to come into play.

How Warranty Wizards can help

Warranty Wizards helps you compare plans from third-party providers and can explain how a plan's terms treat modifications before you buy. If you want to see options, you can request a free quote.