Best 10w40 Semi Synthetic Oil Castrol of 2025

Last updated on 15/10/2025
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1
Castrol Oil Power RS 4T (4-stroke) 10W-40 4-litre
Castrol Oil Power RS 4T (4-stroke) 10W-40 4-litre
Castrol
Free Shipping
Why we love it
  • Semi-synthetic for optimum performance.
  • Extends equipment lifespan significantly.
  • Generous 4 Liter volume.
Main Highlights
  • Semi-synthetic
  • Extends the life span
  • 4 Liter
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9.7
Exceptional
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9.7
Exceptional
Castrol
Castrol Oil Power RS 4T (4-stroke) 10W-40 4-litre
Free Shipping
Why we love it
  • Semi-synthetic for optimum performance.
  • Extends equipment lifespan significantly.
  • Generous 4 Liter volume.
Main Highlights
  • Semi-synthetic
  • Extends the life span
  • 4 Liter
Show More
Value for Money
2
Castrol POWER1 ULTIMATE 4T 10W-40 Motorcycle Oil 4L, Gold
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Castrol POWER1 ULTIMATE 4T 10W-40 Motorcycle Oil 4L, Gold
Castrol
22% OffFree Shipping
Why we love it
  • Engineered for outstanding performance.
  • 5-in-1 formula for maximum efficiency.
  • Excellent protection and smooth riding.
Main Highlights
  • Performance API SN JASO MA2
  • Description With so many engine oils available in the market, don’t you want to know which one offers uncompromising performance? Castrol POWER1 ULTIMATE is engineered for outstanding performance across 5 critical areas. Castrol POWER1 ULTIMATE’s 5-in-1 formula delivers outstanding performance and protection.
  • Application Castrol POWER1 ULTIMATE is suitable for all makes of 4-stroke bikes, both carburetor or fuel injected where JASO MA or MA2 are recommended.
  • Advantages Castrol POWER1 ULTIMATE’s 5-in-1 formula delivers: 1. Excellent acceleration* 2. Excellent protection 3. Smooth riding 4. Keeps the engine cool on long rides 5. Enduring performance Complies with requirements of catalyst equipped engines *Acceleration benefits will be subject to riding style and oil viscosity grade
  • Storage All packages should be stored under cover. Where outside storage is unavoidable drums should be laid horizontally to avoid the possible ingress of water and damage to drum markings. Products should not be stored above 60°C, exposed to hot sun or freezing conditions.
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9.6
Superb
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9.6
Superb
Castrol
Castrol POWER1 ULTIMATE 4T 10W-40 Motorcycle Oil 4L, Gold
22% OffFree Shipping
Why we love it
  • Engineered for outstanding performance.
  • 5-in-1 formula for maximum efficiency.
  • Excellent protection and smooth riding.
Main Highlights
  • Performance API SN JASO MA2
  • Description With so many engine oils available in the market, don’t you want to know which one offers uncompromising performance? Castrol POWER1 ULTIMATE is engineered for outstanding performance across 5 critical areas. Castrol POWER1 ULTIMATE’s 5-in-1 formula delivers outstanding performance and protection.
  • Application Castrol POWER1 ULTIMATE is suitable for all makes of 4-stroke bikes, both carburetor or fuel injected where JASO MA or MA2 are recommended.
  • Advantages Castrol POWER1 ULTIMATE’s 5-in-1 formula delivers: 1. Excellent acceleration* 2. Excellent protection 3. Smooth riding 4. Keeps the engine cool on long rides 5. Enduring performance Complies with requirements of catalyst equipped engines *Acceleration benefits will be subject to riding style and oil viscosity grade
  • Storage All packages should be stored under cover. Where outside storage is unavoidable drums should be laid horizontally to avoid the possible ingress of water and damage to drum markings. Products should not be stored above 60°C, exposed to hot sun or freezing conditions.
Show More
3
Castrol POWER1 4T 10W-40 Motorcycle Oil 4L, White
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Castrol POWER1 4T 10W-40 Motorcycle Oil 4L, White
Castrol
12% OffFree Shipping
Why we love it
  • Optimized for latest motorcycle engines.
  • Features Power Release Technology.
  • Premium part-synthetic formulation.
Main Highlights
  • Suitable for API/JASO
  • Specifications: API SN, JASO MA2
  • Castrol POWER1 4T 10W-40 (Formerly Castrol POWER1 GPS 4T 10W-30) is an advanced, premium quality engine oil developed for the latest generation 4 stroke motorcycle engines.
  • Type: Part Synthetic
  • Power Release Technology reduces loss of friction and optimises motorcycle performance and acceleration
Show More
9.6
Superb
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9.6
Superb
Castrol
Castrol POWER1 4T 10W-40 Motorcycle Oil 4L, White
12% OffFree Shipping
Why we love it
  • Optimized for latest motorcycle engines.
  • Features Power Release Technology.
  • Premium part-synthetic formulation.
Main Highlights
  • Suitable for API/JASO
  • Specifications: API SN, JASO MA2
  • Castrol POWER1 4T 10W-40 (Formerly Castrol POWER1 GPS 4T 10W-30) is an advanced, premium quality engine oil developed for the latest generation 4 stroke motorcycle engines.
  • Type: Part Synthetic
  • Power Release Technology reduces loss of friction and optimises motorcycle performance and acceleration
Show More
4
Motul 5000 4T 10W-40 HC-Tech 4 litre+1 litre free
Motul 5000 4T 10W-40 HC-Tech 4 litre+1 litre free
Motul
Why we love it
  • High-quality semi synthetic oil.
  • Enhanced engine performance guaranteed.
  • Bonus litre included.
Main Highlights
  • Motul 5000 4T 10W-40
  • 4T Semi Synthetic
  • 1 litre free
Show More
9.4
Superb
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9.4
Superb
Motul
Motul 5000 4T 10W-40 HC-Tech 4 litre+1 litre free
Why we love it
  • High-quality semi synthetic oil.
  • Enhanced engine performance guaranteed.
  • Bonus litre included.
Main Highlights
  • Motul 5000 4T 10W-40
  • 4T Semi Synthetic
  • 1 litre free
Show More
5
POWER 1 4T 10W-40 Semi-Synthetic Motorcycle Engine Oil, 8 Litres
POWER 1 4T 10W-40 Semi-Synthetic Motorcycle Engine Oil, 8 Litres
RS Castrol
Main Highlights
  • Power 1 4T 10w-40 semi-synthetic motorcycle 4 stroke engine oil, an advanced, premium quality engine oil developed for the latest generation 4-stroke motorcycle engines.
Show More
9.2
Superb
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9.2
Superb
RS Castrol
POWER 1 4T 10W-40 Semi-Synthetic Motorcycle Engine Oil, 8 Litres
Main Highlights
  • Power 1 4T 10w-40 semi-synthetic motorcycle 4 stroke engine oil, an advanced, premium quality engine oil developed for the latest generation 4-stroke motorcycle engines.
Show More
6
MOTORWORLD Semi Synthetic A3/B4 Engine Oil 10W-40 – High-Performance Semi Synthetic Motor Oil for Petrol & Diesel Engines, ACEA A3 B4 Approved – 5L
MOTORWORLD Semi Synthetic A3/B4 Engine Oil 10W-40 – High-Performance Semi Synthetic Motor Oil for Petrol & Diesel Engines, ACEA A3 B4 Approved – 5L
Motor World
Free Shipping
Why we love it
  • Balanced engine protection guaranteed.
  • Compatible with many vehicle models.
  • Enhances engine cleanliness and lifespan.
Main Highlights
  • Semi Synthetic 10W-40 Engine Oil for Everyday Performance – MOTORWORLD A3/B4 provides balanced engine protection and reliable performance for a wide range of petrol and diesel vehicles, including older and higher mileage engines.
  • ACEA A3/B4 Approved – Broad Compatibility – Meets ACEA A3/B4 specifications, suitable for vehicles requiring mid-range performance oil including many models from Volkswagen, Audi, Vauxhall, Peugeot, Ford, and more.
  • Enhanced Wear Protection and Engine Cleanliness – Combats sludge and deposits while reducing engine wear, promoting smoother operation and longer engine life across a variety of driving conditions.
  • Reliable Performance in High and Low Temperatures – Offers good cold start lubrication and strong film strength under heat and load, ensuring consistent protection in daily commuting or motorway driving.
  • Cost-Effective and Trusted Formulation – A durable, semi synthetic formula that balances value and performance, ideal for both DIY users and professional garages looking for a dependable 10W-40 engine oil.
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9.1
Superb
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9.1
Superb
Motor World
MOTORWORLD Semi Synthetic A3/B4 Engine Oil 10W-40 – High-Performance Semi Synthetic Motor Oil for Petrol & Diesel Engines, ACEA A3 B4 Approved – 5L
Free Shipping
Why we love it
  • Balanced engine protection guaranteed.
  • Compatible with many vehicle models.
  • Enhances engine cleanliness and lifespan.
Main Highlights
  • Semi Synthetic 10W-40 Engine Oil for Everyday Performance – MOTORWORLD A3/B4 provides balanced engine protection and reliable performance for a wide range of petrol and diesel vehicles, including older and higher mileage engines.
  • ACEA A3/B4 Approved – Broad Compatibility – Meets ACEA A3/B4 specifications, suitable for vehicles requiring mid-range performance oil including many models from Volkswagen, Audi, Vauxhall, Peugeot, Ford, and more.
  • Enhanced Wear Protection and Engine Cleanliness – Combats sludge and deposits while reducing engine wear, promoting smoother operation and longer engine life across a variety of driving conditions.
  • Reliable Performance in High and Low Temperatures – Offers good cold start lubrication and strong film strength under heat and load, ensuring consistent protection in daily commuting or motorway driving.
  • Cost-Effective and Trusted Formulation – A durable, semi synthetic formula that balances value and performance, ideal for both DIY users and professional garages looking for a dependable 10W-40 engine oil.
Show More
7
Lucas Oil Semi-Synthetic 10W-40 Engine Oil - 5 Litre
Lucas Oil Semi-Synthetic 10W-40 Engine Oil - 5 Litre
Lucas Oil
Free Shipping
Why we love it
  • Prevents ring sticking issues.
  • Promotes engine cleanliness effectively.
  • Boosts fuel efficiency significantly.
Main Highlights
  • Shields against ring sticking at high temperatures.
  • Maintains superior engine cleanliness.
  • Ensures consistent oil performance and reduces consumption.
  • Enhances fuel efficiency.
  • Long-lasting dispersant and anti-wear capabilities
Show More
9.0
Superb
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9.0
Superb
Lucas Oil
Lucas Oil Semi-Synthetic 10W-40 Engine Oil - 5 Litre
Free Shipping
Why we love it
  • Prevents ring sticking issues.
  • Promotes engine cleanliness effectively.
  • Boosts fuel efficiency significantly.
Main Highlights
  • Shields against ring sticking at high temperatures.
  • Maintains superior engine cleanliness.
  • Ensures consistent oil performance and reduces consumption.
  • Enhances fuel efficiency.
  • Long-lasting dispersant and anti-wear capabilities
Show More
8
Comma EUL5L Eurolite Semi Synthetic 10W40 Motor Oil, 5 Liter, 16 Count (Pack of 4508)
Comma EUL5L Eurolite Semi Synthetic 10W40 Motor Oil, 5 Liter, 16 Count (Pack of 4508)
Comma
5% OffFree Shipping
Why we love it
  • Authentic UK craftsmanship displayed.
  • Compact and ideal size.
  • High-quality, premium selection.
Main Highlights
  • Premium Product
Show More
9.0
Superb
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9.0
Superb
Comma
Comma EUL5L Eurolite Semi Synthetic 10W40 Motor Oil, 5 Liter, 16 Count (Pack of 4508)
5% OffFree Shipping
Why we love it
  • Authentic UK craftsmanship displayed.
  • Compact and ideal size.
  • High-quality, premium selection.
Main Highlights
  • Premium Product
Show More
9
Carlube Triple R 10W-40 API SN/CF Semi-Synthetic Engine Oil R-TEC 32 5L
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Carlube Triple R 10W-40 API SN/CF Semi-Synthetic Engine Oil R-TEC 32 5L
Carlube
3% OffFree Shipping
Why we love it
  • Provides robust engine protection.
  • Suitable for hybrid vehicles.
  • Exceptional fuel economy.
Main Highlights
  • SPECIFICATION - API SN
  • Carlube Triple R 10W-40 R-Tec 32 is a trustworthy, reliable and robust engine oil that provides strong corrosion and wear protection to key components in an engine, maintaining a clean and high-performing engine for trouble-free driving.
  • Carlube Triple R 10W-40 R-Tec 32 is suitable for the latest direct engine petrol engines in preventing low-speed pre-ignition and has proven real-world performance in conventional and hybrid vehicles.
  • They provide exceptional fuel economy particularly vehicles requiring the GM Dexos 1 specification.
  • They are recommended by hybrid vehicle manufacturers because of their strong corrosion control, sludge control and excellent water tolerance.
Show More
8.9
Excellent
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8.9
Excellent
Carlube
Carlube Triple R 10W-40 API SN/CF Semi-Synthetic Engine Oil R-TEC 32 5L
3% OffFree Shipping
Why we love it
  • Provides robust engine protection.
  • Suitable for hybrid vehicles.
  • Exceptional fuel economy.
Main Highlights
  • SPECIFICATION - API SN
  • Carlube Triple R 10W-40 R-Tec 32 is a trustworthy, reliable and robust engine oil that provides strong corrosion and wear protection to key components in an engine, maintaining a clean and high-performing engine for trouble-free driving.
  • Carlube Triple R 10W-40 R-Tec 32 is suitable for the latest direct engine petrol engines in preventing low-speed pre-ignition and has proven real-world performance in conventional and hybrid vehicles.
  • They provide exceptional fuel economy particularly vehicles requiring the GM Dexos 1 specification.
  • They are recommended by hybrid vehicle manufacturers because of their strong corrosion control, sludge control and excellent water tolerance.
Show More
10
Castrol GTX 10W-40 A3/B4 Engine Oil 5L
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Castrol GTX 10W-40 A3/B4 Engine Oil 5L
Castrol
23% OffFree Shipping
Why we love it
  • Superior ACEA A3/B4 specifications.
  • Perfect for API SP engines.
  • Convenient 5L size.
Main Highlights
  • Suitable for API SP, Meets - Fiat 9.55535-D2, MB-Approval 229.3, VW 501 01/ 505 00
  • Specifications: ACEA A3/B4 API SP Meets Fiat 9.55535-D2 / 9.55535-G2 MB-Approval 226.5/ 229.3 Renault RN 0700 / RN 0710 VW 501 01/ 505 00
Show More
8.8
Excellent
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8.8
Excellent
Castrol
Castrol GTX 10W-40 A3/B4 Engine Oil 5L
23% OffFree Shipping
Why we love it
  • Superior ACEA A3/B4 specifications.
  • Perfect for API SP engines.
  • Convenient 5L size.
Main Highlights
  • Suitable for API SP, Meets - Fiat 9.55535-D2, MB-Approval 229.3, VW 501 01/ 505 00
  • Specifications: ACEA A3/B4 API SP Meets Fiat 9.55535-D2 / 9.55535-G2 MB-Approval 226.5/ 229.3 Renault RN 0700 / RN 0710 VW 501 01/ 505 00
Show More

We scanned 350 products

We reviewed these offers relevant to the 10w40 Semi Synthetic Oil Castrol within online retailers such as Amazon, eBay and other local retailers, ensuring we covered all major brands and models. The products we selected come from trusted brands like Castrol, Motul, RS Castrol, Motor World, Lucas Oil, Comma, Carlube, all of which have a reputation for consistently delivering high-quality products that users love and innovative approaches for function & design.
For the best 10w40 Semi Synthetic Oil Castrol in the market, we considered we took a deep dive into 1751 online reviews , focusing on elements like user satisfaction, performance in real-world conditions, and long-term reliability. Our ranking also evaluates each review’s relevancy, authenticity, up-to-dateness and depth so that the comparison is more sound.

We concluded that:

  • The clear winner of our analysis is Castrol Oil Power RS 4T (4-stroke) 10W-40 4-litre. We love many things about this product by Castrol. What sets it apart from the competition is Semi-synthetic for optimum performance, Extends equipment lifespan significantly, Generous 4 Liter volume.
  • The best value product for most shoppers and where user satisfaction is continuously the highest is Castrol POWER1 ULTIMATE 4T 10W-40 Motorcycle Oil 4L, Gold by Castrol based on online reviews by bloggers, experts and online shoppers.
  • The biggest bargain at the moment for 10w40 Semi Synthetic Oil Castrol and the best cost-to-value ratio is Castrol GTX 10W-40 A3/B4 Engine Oil 5Lat Castrol with a 23% discount.
  • Our list of the best 10w40 Semi Synthetic Oil Castrol is updated regularly to reflect new releases and changes in product availability, so be sure to check back often for the latest rankings and discounts.