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The best four-stroke engine oil

  • The best four-stroke oil
  • Suitable for motorcycles and lawnmowers
  • Guide to the best on sale today

Written by Ryan Gilmore Published: 22 August 2022 Updated: 1 February 2024

If you own a modern motorcycle, generator or petrol-powered gardening equipment, chances are it’ll use a four-stroke motor and require special four-stroke engine oil. Despite the oil being different, it still serves the same purpose as other engine oils: lubricating, cooling, cleaning and sealing. Four-stroke engines appeal due to their efficiency, fuel economy, and lower emissions.

Motorcycles and garden equipment may run on four-stroke engines, but the engine size and the performance required from them are very different, so accordingly, the four-stroke oil required to cool and lubricate will be very different, too. There are oils which are ideal as a multi-purpose solution for most four-stroke engines, but if you only have a small lawnmower, there’s no use in using a high-performance oil; indeed, that could do more harm than good. Equally, for goodness sake, don’t use lawnmower oil in your Harley Davidson Low Rider ST.

There are plenty of different four-stroke oils for sale, all designed for different engine types, so read our guide to the best four-stroke engine oils.

Best four-stroke engine oil at a glance:

Editor’s choice: Motul 5000 4T – Buy now from Amazon UK
Best high-performance choice: Castrol Power 1 Racing – Buy now from Amazon UK
Best Budget all-rounder: Comma X-Flow – Buy now from Amazon UK

Best four-stroke engine oil

Editor's choice

Rrp: £13.99

Price: £11.94
This four-stroke oil is an excellent choice for most motorcycles. Offering protection to engines, catalysts and even wet clutches, Motul 5000 is a solid option for most motorcycles. As a semi-synthetic blend, it provides great refinement and efficiency while still being an affordable option.

Pros

  • Excellent choice for most motorcycles
  • Good value option

Cons

  • Not the best choice for high-performance bikes
Best high-performance choice
Price: £13.19
If you're running a high-performance motorcycle then you cannot go wrong with this offering from Castrol. This refined, fully synthetic oil is engineered to be effective at high speed. Its use in motorcycle racing means it'll be more than durable for road use.

Pros

  • Perfect for performance engines
  • Brilliant engine protection

Cons

  • Overkill for non-performance engines
Best budget all-rounder
Price: £22.41
A great budget option, this Comma Oil comes in at less than £5.00 per litre and is suitable for a multitude of different applications, from lawnmowers and chainsaws to petrol and diesel vehicles including those with fuel-injected, multi-valved and turbocharged engines. A great buy if you have multiple different types of four-stroke engines to maintain.

Pros

  • Good value option
  • Helps reduce carbon build-up

Cons

  • Large amount if just for a single garden tool
This SAE30 oil is designed for use in multiple four-stroke engine types. Not as refined as other options, it will still be an acceptable choice for more basic mopeds as well as four-stroke gardening equipment. You should also remember that the SAE30 rating means this oil is made for warmer weather, so it may not be the best choice for a British January.

Pros

  • Can be used for multiple four-stroke engines
  • Good value

Cons

  • Designed for warmer climates
Best for Honda equipment
Price: £12.35
What could give you better peace of mind than using engine oil from the same manufacturer as your engine? Honda produces a lot of gardening equipment; from chainsaws to lawnmowers, and official Honda oil will have been made to protect these four-stroke engines perfectly.

Pros

  • Designed for Honda gardening equipment
  • Can be used in other Honda four-stroke engines

Cons

  • Is not compatible with non-Honda motorcycles

How to choose a four-stroke engine oil:

What four-stroke oil do I need?

Just like with car engine oil, four-stroke oils are designed for different purposes and have different characteristics. Four-stroke engines include mopeds and motorcycles.

More refined (and likely synthetic) four-stroke oils will be designed for high-performance engines used in sports bikes. These will be designed to work at higher temperatures and protect harder-working engines.

Mineral-based oils offer nowhere near the level of protection a synthetic option would offer but are much cheaper. These are perfect for motorbikes with smaller engines, gardening equipment, and generators that do not operate at high temperatures.

Semi-synthetic options offer the added refinement of synthetic whilst still being cheaper to produce. These are perfect for all but the fastest of motorcycles.

What does SAE30 mean?

SAE30-rated engine oil is reading for oil viscosity. In short, this is how long it takes the oil to travel through a hole at a certain temperature. In this case, SAE30 means the oil has a single rating, which means it is better suited to higher temperatures (a lower rating means it’ll be better in cooler climates).

Ryan Gilmore is the Deputy Autos and Tools Editor for Parkers and CAR, specialising in car cleaning and hand tools. With an MA in Automotive Journalism, when he’s not testing buckets he can be found looking at old Porsches.

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