The 10 Best Fuel System Cleaners
This wiki has been updated 20 times since it was first published in April of 2016. Having a little car trouble? Perhaps one of these fuel system cleaners, most of which are good for both solving existing problems and as a preventative, can help. They are designed to flush out crud and deposits in your injector system; stop engine knocking, pinging, and run-on in older cars; improve fuel economy; eliminate rough idling; and reduce spark plug fouling and harmful emissions. When users buy our independently chosen editorial choices, we may earn commissions to help fund the Wiki.
December 07, 2020:
During this latest update, we made a few changes to reflect what we feel are better offerings for several reasons. One example of this is eliminating Lucas Oil 10512 Deep Clean and Lucas Oil 10013 Lubricant as separate options, and instead including the Lucas Complete Renewal Kit, which comes with a bottle of each of this effective formulas. Together, these will clean every aspect of your engine's fuel system, from the injectors to the combustion chamber, which should result in improved performance in across many areas. This freed up a spot to add Sea Foam SF-16, which has proven to be very effective at both removing and preventing deposits. It has also shown to improve cold and hot combustion pressure, which makes an engine start quicker and more powerful.
Another change was to replace Star Brite Star Tron Enzyme with Star Brite Star Tron Enzyme Concentrate. The latter comes in a 32-ounce bottle that is enough to treat over 500 gallons of gasoline. We feel this is not only more economical, but also more practical than the tiny one-ounce bottles the former comes in that can only treat six gallons. Other than one being more concentrated than the other, these are both equally effective at preventing phase separation, rejuvenating old fuel, and removing gunky buildup.
Based on some independent tests, we decided to remove STP 17437 Ultra and added Marvel Mystery Oil Ultimate. While there was nothing inherently wrong with the former, and they are both good at removing and preventing valve and cylinder deposits, the latter is just more versatile. Not only is it suitable for use in petrol and diesel engines, but it can also be used in hybrids and gasoline direct injection systems. Additionally, it doubles as an oil additive, allowing you to use a single solution for many of your maintenance needs.
April 29, 2019:
For the novice, trying to choose a fuel system cleaner can be a bit like trying to decipher Latin, they have no idea where to start. Luckily, we've got you covered and have put together a list of the best options, as well as tried to provide some guidance regarding the best usage of each. If you have a diesel engine, we recommend looking at Lubegard 77012 Booster and Lucas Oil 10013 Lubricant. That isn't to say these options wouldn't also be suitable for gasoline engines, they are just safe and very effective on diesels too. If you have an upcoming emissions test and are worried about passing, grab yourself some Royal Purple 11723 Max-Clean. You'll realize a marked reduction in the amount of harmful emissions leaving your vehicle, and it takes effect very quickly. If you think you car is stumbling because of restricted flow through your injectors, we recommend trying BG 44K Platinum. Along with BG 44K Platinum, Chevron Techron Concentrate and Red Line Complete SI-1 both work very well for high-performance engines. If you need something for your boat, you should probably take a look at STP 17437 Ultra, and if you want something for small outdoor engines, say a lawnmower or string trimmer, we recommend Star Brite Star Tron Enzyme.