Engine Repair vs. Replace Calculator
Your engine failed and the shop handed you a number. Fix it, replace it with a remanufactured engine, or walk away from the vehicle? This calculator runs the rules of thumb mechanics actually use — repair cost against vehicle value, mileage against expected remaining life, and cost per year for each path. It's a starting framework, not gospel: a vehicle you know is rust-free and well-maintained is worth more to you than book value. Runs entirely in your browser.
Rule-of-thumb math, not an appraisal. Assumes the body, frame, and transmission are sound — if they're not, that changes the answer. A targeted repair on a high-mileage engine typically buys 1–3 years; a remanufactured engine is typically warrantied 3 years/100,000 miles and resets wear to zero.
How the Verdict Works
The calculator weighs three things. First, repair-to-value ratio: spending more than half the vehicle's value on one repair is usually bad money unless the vehicle is otherwise excellent. Second, mileage: past roughly 120,000 miles, a single-component repair installs one new part into an engine where every other part carries the same wear — the next failure is often already developing. Third, your time horizon: a reman's nationwide 3yr/100k warranty only pays for itself if you keep the vehicle long enough to use it.
If the verdict points toward replacement, get real numbers before deciding: see what engine replacement actually costs, then compare sellers with the quote comparison calculator and our 2026 rankings.