You may not realise it immediately, but petrol engine cleaners can be the healthiest things to use when you’re achieving high miles. Of course, good engine oil is even more essential, but keeping the petrol system clean is equally so. Over time, carbon deposits build up in an engine, requiring a good treatment with an engine cleaner. If untreated, it can lead to blocking important components, including the injectors.
Petrol engine cleaners are beneficial for a whole load of things. Because they help clean an engine, this simply means the heart of your car can reduce its emissions and improve its MPG slightly.
The best bit? You don’t need to be an experienced mechanic in order to use it. Petrol engine cleaners simply work by inserting it with the fuel and running the engine normally. This means you can simultaneously get on with your everyday life without sacrificing the use of your vehicle. The principle is exactly the same as diesel engine cleaners.
The best petrol engine cleaners at a glance:
Editor’s pick: STP Ultra 5-in-1 Petrol System Cleaner 400ml – Buy from Amazon.
Best value petrol engine cleaner: Redex Petrol System Cleaner 250ml – Buy from Amazon.
Best for catalytic converters and exhausts: Cataclean Complete Fuel and Exhaust Cleaner – Buy from Amazon.
The best petrol engine cleaners
Editor's pick
Rrp: £18.99
Rrp: £18.99
Realistically, there is only a subtle difference between each product. So, we'd recommend the 5 in 1 in a heartbeat, as it should cover all bases and give your injectors and other vital engine parts a good clean.
Pros
- Multi-tasking solution
- Trusted brand
Cons
- Quite easy to get through 400ml in a tank
Best value petrol engine cleaner
The best part is that they are extremely good value for money. So, if you buy in bulk, that's over 1,000 miles of engine cleaning covered. But we recommend you apply this stuff to every tank to get the best out of it. It's especially useful to older fuel-injected cars which might be running a bit lumpy.
Pros
- Great value
- Choice of bottle sizes or 'shots'
Cons
- Not as comprehensive as STP's 5 in 1
Best for cars with EGR systems
Rrp: £9.56
Rrp: £9.56
One particular benefit is the seal cutter on the lid. As someone who has struggled to open the seal of a Redex bottle while other cars are queuing at the petrol station, this is hugely welcomed - and guaranteed a time saver.
Pros
- Seal cutter is useful
- Helps clean a whole host of engine parts
Cons
- 325ml isn't the most generous
Best petrol system additive
It was made in collaboration with the F1 team - presumably using some of the expertise from the engineers regarding the efficiency and concentration of the ingredients. It helps improve efficiency, MPG and power output if your fuel injectors are slightly dirty. And don't, for a second, believe in the 'Mercedes F1 performance' line. Your road car will not suddenly feel like Lewis Hamilton's 2021 car in qualifying mode.
Pros
- Comprehensive engine cleaner
- Uses expertise from a well-known brand
Cons
- Isn't much different to other cleaners
Best for catalytic converters and exhausts
Rrp: £17.49
Rrp: £17.49
It helps clean up the fuel lines, injectors, catalytic converters, EGR valves, as well as improve the essentials such as MPG and efficiency. You can even order a pack of up to six if you want to maintain your engine for around 18 months.
Pros
- Ideal for catalytic converters and exhaust systems
- Quite strong compared to the others
Cons
- Usage is very specific
Things to remember with petrol engine cleaners
Granted, keeping engines squeaky clean isn’t as essential as topping up on screenwash. But while we recommend you keep your petrol injectors and other components clean, just as you would with diesel injectors, there are instances where you won’t necessarily need to. A lot of premium fuels these days, such as Shell V Power, will simultaneously act as an engine cleaner as well as a fuel for your vehicle. And if you use advanced fuels like that, you should be fine.
Where petrol engine cleaners make a substantial difference, though, is with older petrol engines and those with higher miles. Cars that run on E5 petrol and/or have older Bosch injection systems benefit massively from a good clean. The signs that you’ll need petrol engine cleaners are a slight lack in performance, a fairly rough idle, or if the car is running higher exhaust emissions than it should be.
A simple flush clean can instantly make an engine feel smoother, and regularly using the stuff can help maintain its longevity. If, however, you’ve tried fuel injector cleaners and your engine is still feeling rough, then the problem may lie deeper. If you’re lucky, you may just need to change your air filter.
Aaron Hussain is a commercial content writer at Bauer Media writing for Parkers and CAR. He is obsessed with classic cars and anything with a fascinating story to tell.
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