Choosing the right oil for your Cadillac CT4 isn’t guesswork—it’s a spec-driven decision that protects your turbocharged engine and keeps performance crisp between service intervals. Below you’ll find the correct oil type organized by model years (most recent first) and by engine. Every CT4 requires full-synthetic oil that meets GM’s dexos1 specification; viscosity varies by engine and temperature. For Gulf Coast drivers around Gulfport and Biloxi, these recommendations are exactly what our shop uses on CT4 models every day.
2026–2023 Cadillac CT4 & CT4-V (2.0L LSY and 2.7L L3B)
For the standard CT4 lineup during 2023–2026, Cadillac specifies dexos1 full synthetic oil with engine-specific viscosity:
• 2.0L LSY turbo: SAE 0W-20
• 2.7L L3B turbo (Premium Luxury/CT4-V): SAE 5W-30
In areas of extreme cold (below −20°F/−29°C), Cadillac allows SAE 0W-30 in the 2.7L L3B to aid cold starts. These directives are spelled out in the CT4 owner’s manual, and the mapping of engine to viscosity is also reflected in GM’s 2023 service data.
For 2026 specifically, the owner’s manual retains the dexos1 requirement and publishes the same engine family capacities (5.0 L/5.3 qt for 2.0L; 5.2–5.7 L or 5.5–6.0 qt for 2.7L depending on oil pan), confirming continuity with prior years’ guidance. As always, use the viscosity listed above with oil that carries the dexos1 trademark.
2026–2023 Cadillac CT4-V Blackwing (3.6L LF4)
The CT4-V Blackwing’s 3.6L twin-turbo LF4 also uses dexos1 full synthetic oil at SAE 5W-30 for normal operation. GM’s service table and the owner’s manual specify 5W-30 for the LF4, with the same cold-weather exception (0W-30 permitted below −20°F/−29°C). Capacity with filter is approximately 6.6 L/7.0 qt. Track-use notes and other performance items appear in the manual; for daily driving and scheduled maintenance, stick with dexos1 5W-30.
2022–2020 Cadillac CT4 & CT4-V (2.0L LSY and 2.7L L3B)
When the CT4 launched (2020–2022), the oil requirements matched today’s guidance:
• 2.0L LSY turbo: SAE 0W-20 dexos1
• 2.7L L3B turbo (including early CT4-V): SAE 5W-30 dexos1, with 0W-30 allowed in extreme cold.
Those instructions appear in the original CT4 owner’s manual and remain the baseline our technicians follow for these model years.
Why dexos1 and viscosity matter on the CT4
GM’s dexos1 approval isn’t a branding exercise—it guarantees the oil meets deposit control, oxidation stability, turbocharger protection, and low-temperature flow standards tailored for modern direct-injected turbo engines like the LSY, L3B, and LF4. Using oil that merely “meets” a generic API category but lacks dexos1 approval risks issues the powertrain warranty won’t cover. The manuals explicitly call for full-synthetic dexos1 oil and provide the viscosity split by engine; GM’s service documentation echoes the same pairing.
Viscosity is about the right thickness at the right temperature. The 0W-20 spec on the 2.0L LSY reduces drag and supports quick flow at startup, which helps efficiency and turbo health. The 5W-30 spec on the 2.7L L3B and 3.6L LF4 adds a bit more high-temperature film strength under load—ideal for the higher cylinder pressures those engines can generate. If you routinely encounter temperatures below −20°F (uncommon on the Mississippi Gulf Coast), the manuals permit 0W-30 in L3B/LF4 for reliable cranking and oil delivery.
Practical tips from the service lane
• Buy by specification first. Look for the dexos1 trademark on the bottle; then choose the viscosity that matches your engine. The owner’s manuals and GM service tables are aligned on this point.
• Mind the oil life monitor. CT4 models use GM’s Engine Oil Life System; change the oil when indicated or sooner if your driving is mostly short-trip, hot-weather, or dusty.
• Don’t mix viscosities. Topping with the wrong grade dilutes protection. If you’re unsure which engine you have, check your build label or call our advisors with your VIN.
• Use quality filters. GM/ACDelco filters are engineered for these engines’ flow and bypass specs; they are the reference parts in GM’s service literature.
Conclusion
Across every Cadillac CT4 model year to date, the rule is consistent: use full-synthetic dexos1 oil, with viscosity determined by engine—0W-20 for the 2.0L LSY and 5W-30 for the 2.7L L3B and 3.6L LF4, with a 0W-30 allowance for extreme cold on the latter two. That guidance is affirmed by Cadillac owner’s manuals and GM’s official service data and continues through the 2026 CT4. If you’d like Turan-Foley Cadillac to handle your next service, our factory-trained team will fill your CT4 with the exact oil it was engineered to run.
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