Why modern engines burn oil, and what owner complaints reveal
Design choices linked to oil consumption in recent engines, the warning signs owners describe, what counts as normal, and which tracked models currently have the highest engine share in their complaints.
Engine trouble is the single largest category of owner complaints in this index, and a recurring theme in those reports is the same slow-motion failure: the engine uses oil between changes, the low-oil warning appears earlier each time, and eventually a rattle, a stall or a seized bearing follows. Oil consumption used to be a symptom of an old, worn engine. Today it shows up in vehicles that are three years old and still under warranty. This article explains why, what to watch for, and what the complaint data shows.
Why newer engines use more oil than older ones
Several design trends of the last fifteen years each shaved a little fuel consumption and each made oil control a little harder.
- Low-tension piston rings. Rings press less firmly against the cylinder wall to reduce friction. When carbon builds up in the ring grooves, they lose the ability to scrape oil back down into the crankcase, and oil gets burned in the combustion chamber.
- Direct injection. Fuel sprayed straight into the cylinder washes oil off the walls and can dilute the oil in the sump, especially on short cold trips. Some engines then read as overfull on the dipstick while the oil itself has lost its protective properties; others burn the diluted film faster.
- Turbocharging. Turbo shaft seals and the higher cylinder pressures of small boosted engines both push oil where it will be burned.
- Cylinder deactivation. On some engines, owners and mechanics have linked systems that switch cylinders off under light load to lifter failures and oil consumption.
What owners actually describe
The reports behind this index are written by owners, not mechanics. Some describe the oil-pressure or low-oil warning light appearing well before the next scheduled change; some report adding a quart every 1,000 miles, then every 500. Others mention blue or white smoke at start-up, a smell of burning oil, fouled spark plugs and rough idle. In the most serious reports the engine stalls at speed with no warning, and that is what turns a durability nuisance into a safety issue: a stall in traffic can cause a crash.
What counts as normal
There is no single legal definition, and manufacturers' own limits vary. Some have described consumption of around one quart (roughly one litre) per 1,000 miles as acceptable for a modern engine, and dealers apply the manufacturer's threshold when deciding whether to open a warranty claim. The practical point is that documented consumption above the manufacturer's own threshold is generally grounds for a warranty claim while the engine is covered; consumption below it usually is not, however annoying.
What to do if your engine is using oil
- Measure it. Check the dipstick weekly on level ground, the way the owner's manual describes, and write down the mileage and how much you add. Dealers can run a formal consumption test that starts from a documented oil level and measures again after a set distance; ask for one.
- Keep every receipt. Oil purchases, top-ups at the dealer and diagnostic visits are the evidence for a warranty extension, a goodwill repair or a later class action.
- Look for a service bulletin. Manufacturers have issued technical service bulletins for some known consumption problems, for example with a revised piston or ring set. A dealer may not mention one unless you ask.
- Check the recall status by VIN. Some oil-related engine problems have become safety recalls when they could lead to a stall or engine failure. The NHTSA lookup shows open recalls for your exact car.
- File a complaint. Patterns in complaints are one of the ways NHTSA investigations start. A single report will not be answered, but it is counted.
What the complaint data shows
The table below is generated from the current month's data: the tracked models whose owner complaints fall most heavily in the engine category, with each model's share compared with the share across all tracked vehicles. Click a model to see the year-by-year picture, owner excerpts, and any recalls or investigations in that area.
What the data shows now · 2026-10-13
Share across all tracked vehicles: 22.3% · Tracked models with at least 100 complaints, ranked by the share of their complaints in this area.
| Models | Complaints · Engine | Share of complaints | vs. all vehicles | Recent activity |
|---|---|---|---|---|
| Kia Seltos | 351 | 62.8% | 2.82 | Within ±30% year on year |
| GMC Sierra 1500 | 1,833 | 50.1% | 2.25 | Within ±30% year on year |
| Hyundai Kona | 448 | 46.4% | 2.08 | Within ±30% year on year |
| Toyota Corolla Cross | 128 | 43.4% | 1.95 | Falling |
| Jeep Compass | 805 | 43.4% | 1.95 | Within ±30% year on year |
| Mazda CX-5 | 373 | 43.3% | 1.94 | Within ±30% year on year |
| Chevrolet Tahoe | 556 | 43.1% | 1.93 | Within ±30% year on year |
| Ford Escape | 2,255 | 42.9% | 1.93 | Within ±30% year on year |
Reading these numbers carefully
A high engine share does not by itself mean an engine is unreliable. Vehicles with very few complaints overall can show a large engine share simply because there is little else to report, and popular models generate more reports of everything. Use the share together with the model's complaints per year on the road and its trend, both shown on every model page, and read the actual owner excerpts: "oil consumption", "quart" and "stalled" together tell a different story than "check engine light" alone.
If you are shopping for a used car, an engine with a known consumption history is not automatically a bad buy. A documented repair under warranty, a revised part number on the invoice and a clean consumption test are worth more than a model with no history at all. What you want to avoid is an undocumented car from a model year that owners describe as burning oil, sold by someone who has not checked the dipstick lately.