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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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.
  • Except Preorder products are shipped in 48 hours.
  • Delivery to the USA:
  1. Standard Shipping : 3-10 business days
  • If time is of the essence, please consider selecting expedited delivery for faster service.
Exchange/Return Notes
  • We offer a 30-day return/exchange service after receiving.
  • Final sale items are not eligible for returns or exchanges.
  • To process your return/exchange, please contact us at [email protected]
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SKU: 79356900135

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Steve
Los Angeles, US
★★★★★ 4
Fast and easy but I dont trust the process to be fully automated.
The process was very smooth and fairly quick. The only challenge I had was that the CLAIM status showed complete but I had to manually go look up the status. There was no email or notification it was closed. After manually checking the status, I called customer support and they said since I called in, they would process the payout. I wonder if I didnt call in if they would have processed it? Also, the phone rep said they would issue me a amazon egift card but then the next day I received a email saying they mailed out the payout. Very poor communication but so far the process was easy and fast.
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Reviewed in the United States on April 1, 2026
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Glen Armstrong
Carnegie, US
★★★★★ 5
Good protection, easy process
First time filing a claim. Super easy and fast. Nice to have have protection and a smooth claims process when the unfortunate happens..
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Reviewed in the United States on April 25, 2026
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K. Shockley
Houston, US
★★★★★ 5
Ease of making a claim and quick return time for claim.
Very easy to work with.
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Reviewed in the United States on May 21, 2026
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CoolBoomer
Los Angeles, US
★★★★★ 5
Easy Claims Process
It is not a long complicated process to file and resolve a claim. Be warned--sometimes they will want you to send back the defective or damaged product, even if it's not worth the shipping ---they pay. Overall worth the investment though.
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Reviewed in the United States on March 22, 2026
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Gary Wickey
Port Orchard, US
★★★★★ 5
Bella food steamer
You folks have been absolutely great to me easy to work with very polite thank you
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Reviewed in the United States on December 14, 2025

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