Buyer Research

2021 Mazda Mazda6 — Should You Buy One?

Typical asking price: $20,000–$28,000. There is 1 high-severity known issue you need to know before handing over a check.

Deciding between model years? Compare the 12 Mazda Mazda6 years we've written up →

Kestrel Take

The final Mazda6 sold in the US, and a small record with one loud thing in it: 13 of the 17 complaints are the 2.5 engine drinking oil — a quart every 2,000 to 3,000 miles on cars under 20,000 miles, the low-oil light coming on between changes, dealers pointing to valve stem seals and a service bulletin. No recalls, no crashes, no fires. Seventeen complaints is thin and we say so; but three-quarters of them describing the same fault is a pattern, not noise, and the fix is not cheap outside warranty. Buy this year with the oil consumption question answered — a dealer oil-consumption test on file, or seals already done — and confirm whether Mazda's powertrain warranty still has time on it for this VIN. Do that and the last Mazda6 is a genuinely nice thing to own.

What we checked

Checked against public records, 2026-09-25

NHTSA holds 17 owner complaints for the 2021 Mazda Mazda6, and no recall campaigns.

That is too small a record to read a pattern from, so we are not going to pretend otherwise — with numbers this low one owner moves the percentage by a lot. What has been filed is grouped under the engine (13), glass, wipers and mirrors (2), back over prevention (1). Treat those as things to look at, not as the vehicle's known weaknesses. A thin file usually means few of these were sold or few owners filed. It is not evidence the vehicle is trouble-free, and the issues below are our own research rather than a reading of this record.

Counts come from the NHTSA complaint and recall database — free, public, and worth checking yourself.

Known Issues for the 2021 Mazda Mazda6

Ranked by wallet impact. These are documented, recurring problems — not freak accidents. How we decide that.

2.5 engine burns oil — low-oil light between changes, valve stem seals blamedHigh — wallet impact

Thirteen owners, most with under 20,000 miles, report the low oil level light coming on a couple of thousand miles after a change, some measuring a quart every 3,000 miles and rising. Dealers who investigated named the valve stem seals, and owners say Mazda has a service bulletin on it — ask a Mazda dealer to run this VIN and tell you whether the bulletin applies and whether the 5-year, 60,000-mile powertrain warranty still covers it. The fix is a seal job with the head in place at best, a cylinder head at worst. Check the dipstick yourself before the drive; a seller who has just topped it up cannot hide a spotless dipstick on a car that has done 4,000 miles since its last change, so ask when that was and read the sticker on the windshield.

Repair cost (estimate): $1,200–$3,000 for valve stem seals; more if the head comes off

Source: NHTSA complaints filed under the engine (13).

Sunroof glass shattered on the highway; windshield with a distorting optical waveMedium

Two visibility complaints, different problems: a sunroof that exploded outward with nothing hitting it, and a windshield the owner found distorts objects badly enough to make judging distance hard. Neither is common, both are worth a look. Open the sunroof shade and check the glass edges for chips or stress marks, and sit in the driver's seat and look through the lower third of the windshield at straight lines — a fence, a curb — for any ripple.

Repair cost (estimate): $500–$1,200 for sunroof glass; $300–$900 for a windshield plus camera calibration

Source: NHTSA complaints filed under glass, wipers and mirrors (2).

Reversing camera freezes on a stale imageLow

One owner describes the rear camera showing a frozen frame of a street the car was not on, twice taken to a dealer without a lasting fix. It is a Mazda Connect head-unit glitch rather than a camera fault, and the danger is obvious: a still picture of an empty driveway. Shift into reverse three or four times during your visit and watch the image move.

Repair cost (estimate): $0–$900

Source: NHTSA complaints filed under back over prevention (1).

Walk-Away Red Flags

✗Dipstick reading low or the oil-level warning on when you start it
✗Windshield oil-change sticker from 3,000 miles ago and a full dipstick — ask who topped it up
✗Seller cannot say whether a Mazda oil-consumption test was ever done
✗Reversing camera image that lags or freezes
✗Chips or crazing at the edge of the sunroof glass

Good Signs

✓Valve stem seals replaced under warranty, with the Mazda invoice
✓A dealer oil-consumption test on file showing use within Mazda's spec
✓Dipstick on the full mark 3,000 miles after the last documented change
✓Powertrain warranty still in force on the VIN, confirmed by a Mazda dealer
✓Reversing camera image live and steady every time reverse is selected