This full-size SUV splits into two distinct stories. The first-generation trucks with the 4.6L V8 were unkillable, owners routinely hit 400k-500k miles with nothing but oil changes, but rust ate the bodies and air suspension failures totaled otherwise healthy trucks. The current generation (2018-2024) offers serious space, strong towing, and genuine family comfort, but the 10R80 transmission is a documented weak point: multiple owners report rebuilds or replacements before 100k miles at $7k-10k out of pocket. If you're buying used in the 60k-100k mile range, budget for transmission work or get an extended warranty that covers it. The 2025-2026 redesign brings a polarizing oblong steering wheel and touch-heavy controls that owners either adapt to or never stop resenting. Buy this if you need the space and towing capacity, can afford the warranty, and don't mind that it drives more like a truck than a luxury cruiser. Walk if you're stretching the budget or buying high-mileage without coverage.
The Yukon used to be the SUV you bought once and drove forever, GMT800s from 1999-2006 still cruise past 250k miles on original drivetrains, but the current 6.2L V8 has a bearing flaw that causes engines to seize without warning, sometimes at highway speed, often under 30k miles. GM recalled 2019-2024 models but 2025s are failing identically; one owner's engine died at 20k after the dealer promised the issue was resolved. If you need a new Yukon, the 3.0L Duramax diesel is the only powertrain worth trusting, though it's had scattered early turbo failures. Otherwise, find a GMT800 with records and accept 12 mpg, it's the last generation that actually delivers on the reputation.