Lighting: halogen

2017 Cadillac ATS Headlight Bulbs & Lighting Guide

Choose the factory headlight system below to see the correct bulb and recommendation path for this 2017 Cadillac ATS.

Low beam
9012 / HIR2
High beam
9012 / HIR2
Factory setup
Lighting: halogen

Choose the factory system installed in this vehicle. Bulb sizes and recommendations change with that selection.

2017 Cadillac ATS representative vehicle image

Best headlight upgrades

These products were physically tested by BulbFacts, but the tests were not performed in this exact vehicle unless a card explicitly says otherwise.

Lighting: halogen

High/Low Beam Combined: 9012 / HIR2

Best direct replacement

Sylvania SilverStar Ultra

High/Low Beam Combined 9012 / HIR2

BulbFacts testedCorrect bulb size
Reflector Runner-Up

The SilverStar Ultra sits just behind the Night Breaker 200 among normal-wattage reflector picks, but it remains a strong practical choice because it is easy to find and has a whiter beam appearance than many basic halogen bulbs.

General BulbFacts housing test
Read BulbFacts reviewCompare test resultsBuy at Amazon

A matching bulb size identifies fitment; it does not by itself prove optical compatibility or make a conversion a vehicle-specific recommendation.

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Other bulbs

Available exterior and interior lighting data for this model year.

Cargo / Trunk Light
T10Possible fitment — verify installed bulb
Courtesy Light
T10Possible fitment — verify installed bulb
Front Side Marker
T10Possible fitment — verify installed bulb
Front Turn Signal
7443Possible fitment — verify installed bulb
Glove Box Light
T10Possible fitment — verify installed bulb
License Plate Light
T10Possible fitment — verify installed bulb
Map Light
T10Possible fitment — verify installed bulb
Parking Light
7443Possible fitment — verify installed bulb
Rear Fog Light
T15Possible fitment — verify installed bulb
Reverse Light
T15Possible fitment — verify installed bulb
Stepwell Light
T10Possible fitment — verify installed bulb
Technical details and sources

Fitment, factory-system research, and BulbFacts product tests remain separate evidence. A matching bulb size does not by itself make a conversion a vehicle-specific recommendation.

PositionBulb or systemEvidence status
High/Low Beam CombinedLighting: halogen9012 / HIR2Likely fitment
High/Low Beam CombinedLighting: HIDD3SLikely fitment

Each model year opens its own BulbFacts record. Bulb sizes and factory systems are not carried over from adjacent years.

Fitment note: Verify the installed bulb, connector, housing, and factory system before ordering. A bulb-size match is not automatically a conversion recommendation or proof of vehicle-specific testing.