:root { --yellow: #F5C400; --yellow-dark: #D4A900; --steel-900: #0D0F12; --steel-800: #141720; --steel-700: #1C2030; --steel-600: #252A3A; --steel-500: #323848; --steel-400: #4A5268; --steel-300: #6B7490; --steel-200: #9AA3BC; --steel-100: #C8CFDF; --steel-50: #EFF1F6; --white: #FFFFFF; --red: #E03A3A; --green: #2ECC71; --r: 4px; --fh: 'Oswald', sans-serif; --fb: 'Inter', sans-serif; } *, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; } html { scroll-behavior: smooth; scroll-padding-top: 80px; } body { background: var(--steel-900); color: var(--steel-100); font-family: var(--fb); font-size: 16px; line-height: 1.7; overflow-x: hidden; } .container { max-width: 1140px; margin: 0 auto; padding: 0 24px; } h1, h2, h3, h4 { font-family: var(--fh); font-weight: 700; text-transform: uppercase; letter-spacing: 0.5px; line-height: 1.1; } h1 { font-size: clamp(36px, 6vw, 64px); } h2 { font-size: clamp(24px, 4vw, 38px); } h3 { font-size: clamp(18px, 3vw, 26px); } p { margin-bottom: 1em; color: var(--steel-200); } a { color: var(--yellow); text-decoration: none; } a:hover { opacity: .75; } strong { color: var(--white); font-weight: 600; }
.hero { background: var(--steel-800); padding: 80px 0 60px; border-bottom: 1px solid var(--steel-600); position: relative; overflow: hidden; } .hero::before { content: ''; position: absolute; inset: 0; background: repeating-linear-gradient(90deg, transparent, transparent 60px, rgba(245,196,0,.025) 60px, rgba(245,196,0,.025) 61px); pointer-events: none; } .hero-grid { display: grid; grid-template-columns: 1fr 360px; gap: 60px; align-items: start; position: relative; } @media (max-width: 768px) { .hero-grid { grid-template-columns: 1fr; } } .eyebrow { font-family: var(--fh); font-size: 13px; letter-spacing: 3px; text-transform: uppercase; color: var(--yellow); margin-bottom: 16px; font-weight: 600; } .hero h1 { color: var(--white); margin-bottom: 12px; } .sub { font-family: var(--fh); font-size: clamp(14px, 2vw, 18px); color: var(--steel-300); letter-spacing: 2px; text-transform: uppercase; margin-bottom: 28px; } .answer-box { background: var(--steel-700); border-left: 5px solid var(--yellow); border-radius: var(--r); padding: 24px 28px; margin-top: 28px; } .answer-box::before { content: 'DIRECT ANSWER'; font-family: var(--fh); font-size: 10px; letter-spacing: 2.5px; color: var(--yellow); font-weight: 700; display: block; margin-bottom: 8px; } .answer-box p { color: var(--steel-50); font-size: 16px; line-height: 1.65; margin: 0; font-weight: 500; }
.warn-box { background: rgba(224,58,58,.12); border: 1px solid var(--red); border-left: 5px solid var(--red); border-radius: var(--r); padding: 20px 24px; margin: 24px 0; } .warn-box::before { content: '⚠ WARNING'; font-family: var(--fh); font-size: 11px; letter-spacing: 2px; color: var(--red); font-weight: 700; display: block; margin-bottom: 8px; } .warn-box p { color: var(--steel-100); margin: 0; }
.section-label { display: inline-block; font-family: var(--fh); font-size: 11px; letter-spacing: 2px; text-transform: uppercase; padding: 4px 10px; border-radius: 2px; background: var(--yellow); color: var(--steel-900); margin-bottom: 12px; font-weight: 700; } .section { padding: 64px 0; } .section + .section { border-top: 1px solid var(--steel-700); } .section h2 { color: var(--white); margin-bottom: 16px; } .section h3 { color: var(--white); margin-bottom: 14px; margin-top: 36px; } .section h3:first-child { margin-top: 0; }
/* Spec table */ .tw { overflow-x: auto; margin: 24px 0; } table { width: 100%; border-collapse: collapse; font-size: 15px; } thead tr { background: var(--steel-600); border-bottom: 2px solid var(--yellow); } th { font-family: var(--fh); font-weight: 600; text-transform: uppercase; letter-spacing: 0.5px; padding: 14px 16px; text-align: left; color: var(--white); font-size: 13px; } td { padding: 13px 16px; border-bottom: 1px solid var(--steel-600); color: var(--steel-200); vertical-align: middle; } tr:nth-child(even) { background: var(--steel-800); } .badge-yes { display: inline-block; background: rgba(46,204,113,.15); border: 1px solid var(--green); color: var(--green); font-family: var(--fh); font-size: 12px; padding: 2px 10px; border-radius: 2px; letter-spacing: 1px; } .badge-no { display: inline-block; background: rgba(224,58,58,.15); border: 1px solid var(--red); color: var(--red); font-family: var(--fh); font-size: 12px; padding: 2px 10px; border-radius: 2px; letter-spacing: 1px; } .badge-limited { display: inline-block; background: rgba(245,196,0,.12); border: 1px solid var(--yellow); color: var(--yellow); font-family: var(--fh); font-size: 12px; padding: 2px 10px; border-radius: 2px; letter-spacing: 1px; }
/* Stats panel */ .stats-panel { background: var(--steel-700); border: 1px solid var(--steel-500); border-top: 3px solid var(--yellow); border-radius: var(--r); padding: 24px 20px; } .stats-panel h4 { font-family: var(--fh); font-size: 13px; letter-spacing: 2px; color: var(--yellow); margin-bottom: 16px; font-weight: 700; } .stat-row { display: flex; justify-content: space-between; align-items: flex-start; padding: 10px 0; border-bottom: 1px solid var(--steel-600); gap: 12px; } .stat-row:last-child { border-bottom: none; } .stat-label { font-size: 12px; color: var(--steel-300); font-weight: 600; text-transform: uppercase; letter-spacing: 0.5px; flex: 1; } .stat-val { font-family: var(--fh); font-size: 15px; color: var(--white); text-align: right; } .stat-val.red { color: var(--red); } .stat-val.green { color: var(--green); }
/* Info boxes */ .info-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 20px; margin: 24px 0; } @media (max-width: 600px) { .info-grid { grid-template-columns: 1fr; } } .info-card { background: var(--steel-700); border: 1px solid var(--steel-500); border-radius: var(--r); padding: 24px; } .info-card h4 { font-family: var(--fh); font-size: 16px; color: var(--white); text-transform: uppercase; letter-spacing: 1px; margin-bottom: 12px; } .info-card ul { list-style: none; padding: 0; margin: 0; } .info-card li { font-size: 14px; color: var(--steel-200); padding: 6px 0; border-bottom: 1px solid var(--steel-600); display: flex; gap: 8px; } .info-card li:last-child { border-bottom: none; } .info-card li::before { content: '→'; color: var(--yellow); font-family: var(--fh); flex-shrink: 0; }
/* Identify box */ .identify-box { background: var(--steel-700); border: 1px solid var(--steel-500); border-left: 5px solid var(--green); border-radius: var(--r); padding: 24px 28px; margin: 24px 0; } .identify-box::before { content: 'HOW TO IDENTIFY'; font-family: var(--fh); font-size: 11px; letter-spacing: 2px; color: var(--green); font-weight: 700; display: block; margin-bottom: 12px; }
/* FAQ */ .faq-list { margin: 24px 0; } .faq-item { border: 1px solid var(--steel-600); border-radius: var(--r); margin-bottom: 12px; overflow: hidden; } .faq-q { font-family: var(--fh); font-size: 16px; font-weight: 600; text-transform: uppercase; letter-spacing: 0.5px; color: var(--white); padding: 18px 20px; background: var(--steel-700); } .faq-a { padding: 16px 20px; background: var(--steel-800); } .faq-a p { margin: 0; color: var(--steel-200); }
/* Related links */ .related-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(200px, 1fr)); gap: 12px; margin-top: 24px; } .related-link { background: var(--steel-700); border: 1px solid var(--steel-500); border-radius: var(--r); padding: 14px 16px; display: block; color: var(--yellow); font-family: var(--fh); font-size: 14px; letter-spacing: 0.5px; text-transform: uppercase; transition: border-color .2s; } .related-link:hover { border-color: var(--yellow); opacity: 1; }
Volvo VDS-5
Volvo VDS-5 is Volvo’s FA-4 equivalent specification for the 2021+ fuel-efficient D13 engine variant. It requires lower HTHS viscosity than VDS-4.5 (2.9–3.2 mPa·s vs ≥3.5 mPa·s). VDS-5 is NOT compatible with standard D13, D11, D16, or any pre-2021 Volvo engine. Using VDS-5 oil in a VDS-4.5 engine will trigger oil pressure fault codes. Mack’s parallel specification is EOS-5, for the 2021+ fuel-efficient MP8 only.
VDS-5 is NOT the same as VDS-4.5. VDS-5 is FA-4 equivalent with reduced HTHS viscosity. It is ONLY for 2021+ fuel-efficient D13 and the equivalent MP8. Using VDS-5 in a standard D13, D11, D16, or Mack MP7/MP8/MP10 will cause oil pressure fault codes and potential engine damage.
VDS-5 At a Glance
FA-4
2.9–3.2 mPa·s
≥3.5 mPa·s
EOS-5
NO
~0.5–1.0%
VDS-5 vs VDS-4.5 — Full Comparison
These are not interchangeable specifications. VDS-5 is purpose-built for a specific engine variant with tighter tolerances and lower HTHS requirements. VDS-4.5 is the standard for the rest of the Volvo and Mack lineup.
| Requirement | VDS-5 | VDS-4.5 |
|---|---|---|
| API Equivalent | FA-4 | CK-4 |
| HTHS Viscosity | 2.9–3.2 mPa·s | ≥3.5 mPa·s |
| Applicable Engines | 2021+ FE D13, FE MP8 | D11 / D13 / D16, MP7 / MP8 / MP10 |
| FA-4 Compatible | YES | NO |
| Backward Compatible | NO | YES (VDS-4, VDS-3) |
| Mack Parallel Spec | EOS-5 | EOS-4.5 |
| Safe for Mixed Fleets | NO | YES |
The 2021+ Fuel-Efficient D13 and MP8
The fuel-efficient D13 (FE D13) is a specific variant of the D13 engine introduced in 2021. It was engineered from the ground up for lower-viscosity operation — tighter bearing clearances, recalibrated oil pump, and a powertrain ECU tuned to work with FA-4 HTHS chemistry. The result is a measurable fuel economy improvement over VDS-4.5, but only when the correct oil is used.
FE D13 — Key Differences
- 2021+ model year introduction
- Tighter bearing clearances than standard D13
- Requires FA-4 / VDS-5 for rated fuel economy
- Oil pump calibrated for lower HTHS viscosity
- Powertrain ECU tuned for FE spec oil
- ~0.5–1.0% fuel economy improvement on highway
Standard D13 — VDS-4.5
- All model years pre-2021 (and some post-2021)
- Standard bearing clearances
- Requires VDS-4.5 (CK-4) — not VDS-5
- VDS-5 in this engine = fault codes + damage risk
- Also covers D11 and D16 platforms
- If in doubt, run VDS-4.5 — safe for both variants
How to Identify the FE D13: Check the engine serial number plate mounted on the engine block — the FE variant will be identified in Volvo’s fleet documentation. You can also contact Volvo Fleet Services with your VIN. The fuel-efficient variant is marketed specifically as the D13 Fuel Efficiency (FE) spec level. If the paperwork doesn’t explicitly say FE or reference VDS-5, run VDS-4.5.
Mack EOS-5: The Parallel Specification
Mack’s EOS-5 mirrors VDS-5 exactly — it is the FA-4 equivalent specification for the 2021+ fuel-efficient MP8 engine variant. The same compatibility rules apply: EOS-5 is NOT approved for the standard MP8, MP7, or MP10. EOS-4.5 (CK-4) is safe for all Mack engines, including EOS-5 rated platforms, with a small fuel economy trade-off.
Volvo VDS-5 — Common Questions
Only the 2021+ fuel-efficient D13 variant and the equivalent fuel-efficient MP8. All other Volvo and Mack engines — D11, standard D13, D16, MP7, standard MP8, MP10 — use VDS-4.5.
Yes. VDS-4.5 (CK-4) is approved for VDS-5 engines — you lose the fuel economy benefit of FA-4 but there is no damage risk. The dangerous direction is VDS-5 (FA-4) in a VDS-4.5 engine: reduced HTHS at operating temperature causes film collapse on cam lobes, followers, and journal bearings over time.
Check the engine spec plate or consult Volvo fleet services with your VIN. The FE variant was introduced in 2021 and is specifically marketed for fuel economy optimization. If in doubt, run VDS-4.5 — it’s approved for both variants and carries no damage risk.