Why is my Lexus ES 300h getting worse gas mileage than it should?

Short answer: Most ES 300h mileage drops come from weather and use, not a fault. Cold weather and heater use make the engine run more, and A/C, short trips and non-hybrid replacement tires also cost mpg. Check tire pressure and tire type first. If mileage stays low in mild weather on the right tires, have the hybrid system checked.

Symptom: Mileage is in the high 20s or mid 30s, well under what you expected, or it dropped after a season or new tires.

What to check first

1. Set the tires to the pressure on the door sticker.
2. Check whether your tires are a low rolling resistance model.
3. Compare mileage in mild weather vs cold weather.
4. Note how much is short-trip driving.
5. Ask the dealer to check the hybrid system and battery if mileage stays low in mild weather.

Likely causes

1. Cold weather and heater use. A hybrid's engine runs more in cold weather to warm itself and the cabin, so mileage drops a lot in winter.
2. A/C use and short trips. Short trips never let the engine warm up enough to shut off often.
3. Tires that aren't low rolling resistance. Hybrids come with tires that roll easier. Replacement tires that grip more often cost a few mpg.
4. Low tire pressure. Soft tires drag more and waste fuel.

What it usually costs

Owners in these threads didn't post prices.

Is it safe to keep driving?

Yes. Lower mileage isn't a safety issue unless warning lights come on.

DIY or shop?

Tire pressure and tire choice are DIY. Hybrid system tests are a dealer job.

Recalls, bulletins and complaints in plain words

• Related recalls: NHTSA lists recall 20V064000 for some 2020 ES 300h: porosity in the engine castings can crack and leak coolant. It isn't a mileage recall, but coolant loss or overheating on a 2020 is worth a VIN check. Check your VIN at nhtsa.gov/recalls. If your car is part of a recall, the dealer fixes it for free.
• Plain words: The complaint count below shows how often owners reported problems that mention these words to NHTSA. A count is not proof of a defect.
• NHTSA complaints: 13 keyword-matched complaints for Lexus ES 300h 2013–2020 (of 103 unique complaints queried, NHTSA complaints API by model year, queried 2026-10-30; keywords: mpg, mileage, fuel economy, hybrid battery) (NHTSA returned no data for 19 model-year queries). This counts complaints that mention these words. It is not a defect finding.

What owners report

• In 2019 Lexus ES 300h gets fewer mpg than advertised on Car Talk, a 2019 ES 300h was getting about 29 mpg in town and no more than 35.5 on the road six months after purchase. Members said cold weather and heater use cut hybrid mileage a lot and to check again in warmer months.
• In 2016 Lexus ES 300h gas mileage drop on Car Talk, a 2016 ES 300h dropped from 40 mpg to 35 and the dealer found nothing wrong. Members pointed to A/C use, temperature, replacement tires that aren't low rolling resistance and driving habits.

Quick tip

Track a full tank in spring before you worry. Many owners with this complaint turn out to be comparing winter numbers to the window sticker.

Vehicle focus: Lexus ES 300h, 2013-2020, 2.5L hybrid.

Safety / mechanic note

If the hybrid warning or check-engine light comes on, Verify with a mechanic.