FS365 Vs ACF50 – No that’s wrong

FS365 Vs ACF50 – No that’s wrong

It is just wrong. There is no comparison, and it isn’t because one is better than the other. FS365 from Scottoiler and ACF-50 Anti Corrosion Lubricant are excellent products that achieve the same objective, but they do so in very different ways.

Comparing the two products is like trying to claim that my KTM 1090 is better than a Harley Street Glide. They are both motorcycles. They both have two wheels. They are both V-twins, and that is about where the comparisons stop.

It is winter. The roads are covered in crap. I might be riding through the dark months, or perhaps I’ve parked my beloved motorcycle until the temperature goes back above “feckin’ freezing”.

Either way I want to protect my motorcycle, so what do I do?

ACF50 and the equally good XCP are barrier protectors while FS 365 is a water-based corrosion inhibitor that works on a chemical level to stop the process of corrosion. 

And now we have cleared that up … what is the right tool for the job?

ACF-50 and XCP

Barrier protectors do exactly what it sounds like. They create a barrier between the surface of your motorcycle and the harsh winter environment. A layer that is designed to stop any dirt, water and salt (which combine to make acid) from eating your motorcycle.

Once you have applied a barrier protector it usually lasts a long time. Just remember to look at what is in your favourite motorcycle wash. No point applying ACF-50 or XCP if you then wash it off with a hard motorcycle cleaner.

Motorcycle Cleaners

To get the best results from ACF-50 or XCP, you need to apply it to a clean motorcycle. I’m not talking about a quick wash; I’m talking spotless – eat your dinner off the engine casings – clean.

ACF-50 motorcycle ProtectonWhen Trevor, the local AllYearBiker representative, winterised my bike a few years back, the application of ACF-50 or XCP took him about 10 minutes. Cleaning the bike ready to be coated in ACF-50, took him over 2 hours.

The surgical level of cleaning is required to ensure that you don’t trap any existing dirt or salt against the bike, which would make the situation worse. As ACF-50 does its job and seals out the winter weather, that seal will also lock in anything nasty left on the bike. A spotlessly clean motorcycle is vital before applying ACF-50 or XCP.

Talking to a motorcycle valeting company for the article on motorcycle cleaners, they have a love-hate relationship with ACF-50. While it is excellent at protecting the motorcycle, it’s also sticky stuff that collects dirt. If it isn’t cleaned off before more is applied, the ACF-50 / XCP builds up and is the devil’s own job to shift.

Nonetheless, if you are putting your motorcycle away for those annoyingly dark and cold months, a surgical clean and a coating of ACF-50 or XCP is an excellent way to protect your motorcycle while it is in hibernation.


FS365 approaches motorcycle protection from a different angle. Rather than create another barrier protector in the same style as ACF50, Scottoiler – the manufacturers of FS365 – decided to investigate how to stop the corrosion process from happening in the first place.

Rather than remove anything that might cause corrosion and then putting a barrier in the way, FS365 works by neutralising the corrosive chemicals as they arrive on your motorcycle.

Here comes the science bit … the full explanation is on the FS365 website.

Pure water will not cause corrosion; however, water absorbs acidic gases such as carbon dioxide. Then there is the rock salt on the roads. Mix that with water, and you get a weak solution of hydrochloric acid.

FS365 is formulated using mild alkalis and chemical compounds known as pH buffers to help neutralise the acidic elements.

The process of rusting and oxidisation requires water vapour, air and time. If you add salt and heat as catalysts, then the process speeds up. Neutralise the acidic elements, and the corrosion process stops.

FS365 acts as a corrosion inhibitor in two further ways:

  • By supplying a lubricant to all metal surfaces which builds up as you re-apply, protecting them from the air
  • By reducing the catalytic effect of salt which is trying to speed up the corrosion process

Scottoiler FS365 Motorcycle ProtectionFS365 is a blend of mineral oil, anti-corrosion additives, water and surfactants, which are clever molecules that spontaneously bond with each other to help the elements in FS365 combine into a stable solution. (got to love science)

When you apply this combination to your motorcycle, it forms an effective layer of protection against corrosion, clinging to all surfaces and building up over time with each application.

FS365 is water-soluble and biodegradable, which helps remove any dirt that sticks to the FS365 layer as it is easily washed away. Once you have washed the bike, apply another layer of FS365 to renew the protection.

Essentially, FS365 works at a chemical level to reduce the corrosive salt and water mixtures’ acidity back to a neutral level, thereby stopping the corrosion process before it starts.

And because it has mineral oil in the formula, FS365 also provides barrier protection, but that is not the primary way it protects against corrosion.

As if all of that wasn’t enough, there is the added bonus that with continued reapplication, FS365 makes cleaning your motorcycle easier as it can be easily removed – along with the dirt it collects – with any decent motorcycle wash.

So if you do happen to get any on your tyres or brake discs when you are using FS365, all you need to do is wash it away.

As water is one of the primary elements in corrosion, why does FS365 contain water?

Remember those clever surfactants … One of the unique things about FS365 is that it is a stable (doesn’t separate) microemulsion of oil and water plus a lot of anti-corrosion additives. The water is used to make applying FS365 easy – you spray it on and wipe any excess with a cloth.

The water acts as a carrier to ensure FS365 can get into all of the hard to reach places. After the water evaporates, you have a film of oil with anti-corrosion properties covering your motorcycle. 

Using water as a carrier, it can be sprayed onto a wet or dirty bike. FS365 will simply mix with the road grime and salt solution on your motorcycle and start neutralising the acidic properties.

Do they work?

Yes – Next question please.

ACF50 and XCP have a long history as excellent barrier protectors. I’ve been told that ACF-50 was developed for the US Airforce, and the next person said the US Navy. Whatever the truth is, it makes no difference. ACF50 and XCP both provide excellent protection for your motorcycle when a barrier protector is what you need.

As well as being the founder of Scottoiler, Fraser Scott is an all-year-all-weather biker. To test FS365, he bought a Ducati and rode it through the winter, never cleaning it. He did, however, spray the Ducati with FS365 on a regular basis to protect it.

At the end of the winter, the Ducati as given to Ducati Glasgow, who hosed down and washed the bike, which was spotless and corrosion-free.

Motorcycle Corrosion Protection

If you want to protect your motorcycle FS365, ACF50 and XCP will all do an excellent job, providing they are used for the right job.

FS365 is not meant for motorcycles in long term storage. This is where careful preparation and ACF50 or XCP are the right tools for the job. If you apply FS365 once and then do the typical “wait and see if it rusts” comparison test you can find all over the internet, ACF50 and XCP will come out best. It is how they are designed to be used.

However, if you ride all year, applying FS365 regularly to your motorcycle, will actively stop the acidic crap on the roads from eating your motorcycle.

FS365 Vs ACF-50

And all of that is why trying to compare FS365 from Scottoiler with ACF-50 Anti Corrosion Lubricant or XCP Rust Blocker is just wrong. FS365 doesn’t really have a competing product.

I’ve seen people compare FS365 with WD-40, which is a blend of lubricating oils and water displacement additives. WD-40 stands for Water Displacement – 40th formula. It is perhaps the closest comparison product for FS365 but is still a long, long way off.

If someone tries to compare ACF50 with FS365, may I suggest using the time to daydream of exciting corners until they have finished?

Spring Salt

One final thought for you. Remember to keep using FS365 once the weather warms up and the sun comes out.

Road salt will sit on the side of the road for months. As the weather warms up and April showers occur, your motorcycle could be getting covered in corrosive road water, just as easily as it does in Winter.


I’ve been using FS365 for a couple of years and other than a free sample bottle given to me and lots of other people at Motorcycle Live one year, I’ve always bought my own. With my own money too.

The same goes for AF50 and XCP, I’ve always bought my own.

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