SKU: 79356900135

BOSS Lubricants CK-4 Heavy Duty Diesel Engine Oil Full Synthetic 0W-40 · 5W-40 & Extreme 10W-30 · 15W-40 Low Ash EGR DPF SCR On/Off Highway

Sale price$152.95 Regular price$169.95
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Ships within 48 hours · Estimated delivery Jul 30 - Aug 4

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Description

BOSS Lubricants CK-4 Heavy Duty Diesel Engine Oil Full Synthetic 0W-40 · 5W-40 & Extreme 10W-30 · 15W-40 Low Ash EGR DPF SCR On/Off HighwayPremium Canadian made BOSS API CK 4 heavy duty diesel engine oils choose premium Full Synthetic (true Group III 0W 40 & 5W 40) for ultimate cold weather flow, fuel economy, and extended drains in extreme Canadian winters, or Extreme (10W 30 fuel economy & proven 15W 40) for outstanding soot control, wear protection, oxidation aeration resistance in high load, high soot, mixed fleets. Both lines are low ash formulations engineered to exceed the latest

Premium Canadian-made BOSS API CK-4 heavy-duty diesel engine oils – choose premium Full Synthetic (true Group III – 0W-40 & 5W-40) for ultimate cold-weather flow, fuel economy, and extended drains in extreme Canadian winters, or Extreme (10W-30 fuel-economy & proven 15W-40) for outstanding soot control, wear protection, oxidation/aeration resistance in high-load, high-soot, mixed fleets. Both lines are low-ash formulations engineered to exceed the latest CK-4 requirements (including new oxidation & aeration tests) for 2010+ EGR / 2017+ GHG engines with DPF/SCR systems while being fully backward compatible with CJ-4/CI-4+ and older specs – perfect for trucking, construction, agriculture, mining, logging, and severe-service diesel engines.

Deliver exceptional piston cleanliness, valve train protection, shear stability, TBN retention, and extended drain capability even under severe operating conditions with high soot loading and fuel sulfur levels.

✅ Key Benefits:

  • Exceeds API CK-4 & backward compatible to CJ-4, CI-4+, CI-4, CH-4
  • Outstanding soot thickening control & aeration resistance – passes latest CK-4 tests
  • Superior wear protection for cams, bearings, cylinder liners & valve train
  • Exceptional piston deposit control & engine cleanliness
  • High TBN retention for extended drain intervals & acid neutralization
  • Excellent oxidation, thermal & shear stability – stays in grade longer
  • Low-ash formulation protects DPF, SCR & catalytic converters
  • Outstanding cold-start performance & pumpability (especially low-vis grades)
  • Proudly formulated and bottled in Canada

✅ Grade-Specific Advantages:

  • 0W-40 Full Synthetic → Ultimate arctic cold-start flow (-54°C pour), maximum fuel economy, extended drains in extreme cold fleets
  • 5W-40 Full Synthetic → Superior all-season performance, high VI, maximum protection in severe duty & high temperatures
  • 10W-30 Extreme → Fuel-economy optimized for modern GHG engines, lower viscosity, excellent soot handling
  • 15W-40 Extreme → The #1 heavy-duty workhorse – proven high-soot protection, perfect for mixed fleets & hot climates

Typical Physical Specifications (representative values):

0W-40 Full Synthetic • Kinematic Viscosity @ 40°C: 87.3 cSt • Kinematic Viscosity @ 100°C: 15.1 cSt • Viscosity Index: 180 • CCS @ –35°C: 5360 cP • Pour Point: –54°C • Flash Point: 188°C

5W-40 Full Synthetic • Kinematic Viscosity @ 40°C: 87.8 cSt • Kinematic Viscosity @ 100°C: 14.8 cSt • Viscosity Index: 177 • CCS @ –30°C: 5600 cP • Pour Point: –45°C • Flash Point: 225°C

10W-30 Extreme • Kinematic Viscosity @ 40°C: 81.7 cSt • Kinematic Viscosity @ 100°C: 12.2 cSt • Viscosity Index: 145 • Pour Point: –39°C • Flash Point: 237°C

15W-40 Extreme • Kinematic Viscosity @ 40°C: 113.9 cSt • Kinematic Viscosity @ 100°C: 15.6 cSt • Viscosity Index: 145 • Pour Point: –33°C • Flash Point: 226°C

Meets or Exceeds: • API CK-4, CJ-4, CI-4+, CI-4, CH-4 / SN (5W-40) • Cummins CES 20086, 20081, 20087 • Detroit Diesel DFS 93K222, 93K218, 93K233 • Volvo VDS-4.5, VDS-4, VDS-3 • Mack EOS-4.5, EO-O Premium Plus & earlier • Caterpillar ECF-3, ECF-2 • Mercedes MB 228.31 • MAN M3575 • Ford WSS-M2C171-F1 • Renault RLD-4 • MTU Category 2.1 • ACEA E7 • JASO DH-2 • Suitable for virtually all North American, European & Asian on/off-highway diesel engines requiring CK-4 or earlier specifications

EHC is included in the price

 

Safety Data Sheet

Shipping Notes
  • Free Standard Shipping on $100+ Orders to the USA.
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  • Delivery to the USA:
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Exchange/Return Notes
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  • Final sale items are not eligible for returns or exchanges.
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SKU: 79356900135

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RedLove1969
Fort Morgan, US
★★★★★ 5
Great item!
Great item a must buy 😁
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Reviewed in the United States on April 21, 2026
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SirchainsawCharlie
Natrona Heights, US
★★★★★ 5
Fits 2007 Honda crv.
It fits my 2007 Honda crv and sealed very well.
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Reviewed in the United States on April 15, 2026
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Kelsey
Lexington, US
★★★★★ 5
Fits 2007 Honda CRV
Fits 2007 Honda CRV.
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Reviewed in the United States on June 3, 2025
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R + K Z
Belleville, US
★★★★★ 3
Filters well but causes air flow restrictions
Very thick and does filter well however it is so thick it actually blocks quite a bit of air flow
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Reviewed in the United States on October 27, 2020
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Heather gomez
Charlottesville, US
★★★★★ 5
Did not disappoint!
Perfect Fit: Bolted right up to the engine block without any shimmying or modification needed. ​Strong Crank: The motor sounds powerful and turns the engine over significantly faster than my old, dying unit. Once hooked up, the car fired up instantly on the first turn of the key. No grinding, no clicking, just a smooth, high-torque start. Price: A lot more cheaper then your average auto parts stores. ​Build Quality: The solenoid connections are solid and the threads were clean. Packaging: The box arrived on time but a bit beat up, but the starter itself was well-protected in bubble wrap and undamaged.
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Reviewed in the United States on April 2, 2026

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