The small turbo four that replaced Honda's naturally aspirated engines across much of its lineup — efficient on paper, but with a specific, well-documented complaint about fuel mixing into the engine oil in cold climates.
Short trips in cold weather can prevent this engine from reaching full operating temperature long enough to burn off unspent fuel, which instead ends up diluting the engine oil — raising the oil level on the dipstick and, over time, reducing lubrication effectiveness. The issue is well documented enough that Honda issued a software update aimed at mitigating it, though reports of the underlying symptom have continued on a subset of affected examples even post-update, particularly in colder climates.
Not a guarantee, but a pattern seen consistently across owner forums and independent-garage reporting.
Oil dilution is tied to climate and driving pattern rather than purely wear-related, and can appear on relatively low-mileage examples in cold regions.
Checking oil level and smell at every interval is a more meaningful indicator than mileage alone for this specific issue.
Check the oil dipstick yourself if possible — an oil level reading above the full mark, or oil that smells strongly of gasoline, are the clearest signs of this issue.
Ask whether the software update addressing this issue has been applied, and whether the owner has noticed the symptom since.
If you live in a cold climate and do mostly short trips, treat this checklist as especially important regardless of what the seller reports.
Model-specific pages, with notes on how it behaves in that particular car.