The Most Expensive Thing to Change on a Car

For most gasoline or diesel vehicles, the engine is the single most expensive component to replace; for modern electric vehicles, it’s the high‑voltage traction battery pack. Either job can easily run into the five‑figure range, and on luxury or performance models it can exceed the car’s market value, prompting insurers and owners to consider totaling or selling instead of repairing. Here’s how those costs break down in 2025, why they’re so high, and what you can do to avoid them.

Why engines and EV batteries top the list

An internal‑combustion engine is the mechanical heart of a conventional car: thousands of precision parts, tight tolerances, extensive labor to remove and reinstall, and complex calibration afterward. In an EV, the battery pack is the car’s energy reservoir and a structural component in many designs. Packs are large, heavy, require specialized high‑voltage handling, and are expensive to ship, insure, and warrant. In both cases, parts and labor stack up quickly—and the ripple effects (cooling system work, programming, mounts, fluids, and safety checks) add thousands more.

What it costs in 2025

Internal‑combustion engine replacement

On mainstream models, a replacement engine (used, rebuilt, or remanufactured) typically costs $4,000 to $10,000 installed. Dealer replacements with new or factory‑reman units commonly land between $7,000 and $15,000 when you include labor, ancillary parts, and programming. European luxury and performance engines can run $12,000 to $25,000 installed, while exotic supercar powerplants can exceed $50,000 to $100,000. Labor rates of $120 to $250 per hour at dealerships and 15–30 hours of book time are typical, with more time for turbocharged or tightly packaged engines.

EV and hybrid battery pack replacement

High‑voltage pack replacements vary widely by make and capacity. In 2025, many mainstream EV packs cost roughly $8,000 to $18,000 installed. Larger or premium‑brand packs—think long‑range sedans, SUVs, and trucks—often total $15,000 to $30,000, with some outliers higher. Examples: compact EVs can be under $10,000; popular midsize packs frequently fall in the $12,000 to $20,000 range; full‑size trucks and premium models can approach or exceed $25,000. Hybrids and plug‑in hybrids usually cost less than full EVs, often $2,000 to $8,000 for hybrids and $5,000 to $12,000 for PHEVs, depending on chemistry and availability. Many OEMs provide 8‑year/100,000‑mile battery warranties (some longer), which can offset these costs if failure occurs within terms and capacity thresholds.

Transmissions come close

Automatic transmission replacements on mainstream vehicles typically run $3,000 to $7,000, CVTs are often $3,000 to $6,000, and dual‑clutch or high‑performance gearboxes can range from $7,000 to $15,000 or more. On high‑end European or exotic cars, specialized transmissions and transaxles can cost $20,000 to $60,000 installed, making them a close second to engines and EV batteries in overall expense.

Other high‑cost replacements you might not expect

Beyond engines, batteries, and transmissions, several systems can generate staggering bills, particularly after collisions or on specialty vehicles. The following items commonly surprise owners with their price tags.

• Unibody or chassis structural repairs: Major frame or monocoque replacement is rarely economical; extensive straightening and panel replacement can easily exceed $15,000 to $30,000 and often leads to a total loss.
• Airbag system after deployment: Multiple airbags, sensors, modules, seatbelt pretensioners, and dash components can add up to $5,000 to $15,000+ on modern cars.
• Advanced driver‑assistance sensors and calibration: Radar, lidar, cameras, and related modules plus post‑repair calibration commonly run $1,000 to $5,000; complex cases can be higher.
• Aluminum or carbon‑fiber body panels: Materials and labor (including bonding/riveting) make some panel replacements $2,000 to $10,000 each; carbon monocoque repairs are specialty‑only and often uneconomical.
• Air suspension and rear‑steer systems: Full axle set replacements with compressors and control units can total $3,000 to $10,000+.
• Digital dashboards and infotainment: Integrated displays and domain controllers can cost $1,500 to $5,000 or more, especially when programming and security coding are required.

While these items may not always surpass engine or battery costs, they can push repair totals into five figures—especially when several systems are affected in the same incident.

What drives the price up

The final bill reflects more than the headline part. Several factors combine to determine whether a repair is merely painful—or prohibitive.

• Parts sourcing: New OEM components are pricier; rebuilt, remanufactured, or used units can reduce cost but may affect warranty length and availability.
• Labor time and access: Tightly packaged engine bays and battery trays increase hours; subframe drops and specialized lifts add complexity.
• Calibration and programming: Modern powertrains and safety systems require software setup, immobilizer pairing, and road‑test calibrations.
• Ancillaries and consumables: Mounts, gaskets, fluids, hoses, coolants, pyrotechnic devices, and fasteners add hundreds to thousands.
• Shop type and region: Dealer rates are higher; independent specialists can be lower but may have longer lead times; regional labor and tax rates vary.
• Shipping and hazardous handling: Large or high‑voltage parts incur freight, crating, and safety surcharges.
• Supply constraints: Backorders and limited production runs for niche models inflate prices and extend downtime.

Understanding these drivers helps explain why two seemingly similar jobs can differ by thousands of dollars across brands, trims, and regions.

Repair versus replace: how shops and owners decide

When a major component fails, a structured decision process helps determine the best path forward—technically and financially.

1. Confirm the diagnosis: Request detailed fault codes, compression/leak‑down results (ICE), or battery health reports and isolation tests (EV).
2. Check coverage: Review factory powertrain or battery warranties, extended service contracts, and recall or service campaign eligibility.
3. Compare part options: New OEM vs. factory reman vs. reputable reman vs. low‑mileage used; weigh cost, availability, and warranty terms.
4. Seek multiple quotes: Include a dealer and at least one independent specialist; ensure quotes list parts, labor hours, programming, and taxes.
5. Consider partial or modular repair: Engine top‑end rebuilds or EV battery module replacements can sometimes be viable at lower cost.
6. Assess the car’s value: If repair exceeds 60–100% of market value, a sell, total, or donor‑vehicle strategy may be smarter.
7. Account for downtime: Parts lead time, rental costs, and logistics may tilt the decision toward replacement vehicle options.

A transparent quote with line items—and a clear explanation of risks and warranties—makes it easier to justify investing in the repair or moving on.

Ways to reduce risk and out‑of‑pocket cost

While no car is immune to big‑ticket failures, a few proactive choices can lower the odds and soften the blow if they occur.

• Follow maintenance schedules: Oil changes, coolant and transmission services, and thermal‑management checks protect engines, packs, and gearboxes.
• Battery care for EVs: Keep software up to date; avoid chronic 0–100% cycles; moderate fast‑charging when practical; maintain proper cooling system health.
• Buy the right coverage: Evaluate extended warranties from reputable providers and ensure your insurance covers ADAS calibration and OEM parts where required.
• Choose proven drivetrains: Research reliability records and parts availability before purchase; avoid orphaned models with scarce components.
• Pre‑purchase inspections: A compression test (ICE) or battery health report (EV/PHEV) can prevent inheriting a looming five‑figure bill.
• Get quotes for reman/used assemblies: Quality reman or low‑mileage used components can cut costs dramatically with acceptable warranties.

No strategy guarantees zero risk, but layered prevention and smart shopping significantly reduce the likelihood of facing the most expensive replacements.

Summary

The most expensive single item to change on a car depends on the powertrain: engines lead for gasoline and diesel vehicles, while high‑voltage battery packs top the list for EVs. In both cases, installed costs commonly reach five figures in 2025 and can soar far higher on premium or exotic models. Transmissions, major structural repairs, and complex safety or driver‑assistance systems can also produce eye‑watering totals. Understanding the cost drivers, exploring part alternatives, leveraging warranty coverage, and maintaining the vehicle diligently are your best defenses against a repair that rivals the value of the car itself.