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Red Line

Red Line 60103 SI-1 Complete Fuel System Cleaner, Cleans and Prevents Corrosion in Fuel Systems, Cleans Injectors, Carburetors, Valve and Combustion Chamber Deposits - 15 Ounce (2 Pack)

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Condition: New
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Arrives Wednesday, Nov 4
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At a glance

Condition
New
Size
15 Fl Oz (Pack of 2)
Item Form
Liquid
Scent
Unscented
Special Features
Concentrated
Item Volume
15 fl oz
Material Type Free
en_AE

Features 5

  • DESIGNED TO EXCEED EXPECTATIONS: Red Line complete SI-1 fuel system cleaner treatment for cleaning and preventing corrosion in fuel systems
  • PERFORM AND PROTECT: Fuel additive cleans injectors, carburetors, valve and combustion chamber deposits with a powerful, concentrated blend of high-temp and low-temp detergents
  • EFFICIENT FUEL BURN: Gas treatment that enhances gasoline stability, while reducing the build up of gum and varnish formation
  • EASY TO USE: Use one bottle per tank for most effective treatment, additive cleans nearly 100% efficiency in one treatment

Specs 17

Brand Red Line
Item Form Liquid
Scent Unscented
Specific Uses For Product Automotive Interior
Material Feature Unscented
Special Features Concentrated
Brand Name Red Line
Manufacturer Red Line

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Top Amazon Reviews

It is either this, Gumout, or Royal Purple MaxClean. These three WORK!
Size: 15 Fl Oz (Pack of 1)
I have had several cars and I have come upon Redline's reputation as perhaps THE premier maker of synthetic lubes; (*cue: AMSOIL trolls, chime in now.) After doing a lot of extensive reading about motor oil on Bob Is The Oil Guy (Google it,) I became convinced that Redline was perhaps THE best oil; and while there is no "best oil," If I was going to spend big money on oil or simply wanted the best, I would choose Redline for its proven reputation with its oils, AND HAVE REMAINED SO EVEN WITH SLIGHT FORMULATION CHANGES (Read up on API SN and how it differs from API SM and API SL, etc, there is less of what was known to be the good stuff and it has been replaced with new good stuff, /endrant) - Or, perhaps, Royal Purple for a high performance, specialty oil. Honorable mentions to Mobil 1 and Pennzoil for ultra good oils as well (do you see what I did there?) On the fence about many others; nothing "wrong" with them, but why buy Castrol... That said, this review is not about motor oil. It is about fuel system treatment. And Redline SI-1 specifically, at that! Now let me tell you why I like this Redline product... Firstly: PEA. I forget what PEA stands for, but, as far as I know, it is about the ONLY chemical or ingredient in a fuel system cleaner or injector cleaner - four categories? Well, if it goes in the fuel, then it goes where the fuel goes... So get the strongest one....... - that ACTUALLY CLEANS. Let us make a list of those that are a SHAM, and really DONT have ANYTHING of VALUE in them: - STP - Slick 50, OLD AND NEW formula.. - Lucas (there, I said it. I have some experiences as well as research with products from this company, not relevant to this review.) - Prestone - Pro-Long - SEAFOAM (!!!) - "Most of the shelf".. money-wasters.. makes Walmart happy.. -- WHY? BECAUSE THYEY DO NOT HAVE PEA, or VERY LOW AMOUNTS but more like NOT, if you look at Product Data Sheets. Labels lie. Product Material Data Sheets? They don't lie. Now, back to WHAT WORKS: I have found that there are only three, criterion: HIGH IN PEA, therefore WORKS... - Gumout with REGANE (Regane is the PEA, three GUMOUT products have it: The All-In-One, the High Mileage, and another yellow liquid version, High Mileage is Orange and All In One is amber) - Royal Purple MaxClean (** HAS PEA; just different chemicals to MAKE it PEA;) - Redline SI-1. ^^ Now.. Out of these three, Redline has the HIGHEST amount of PEA in it. Gumout has a lot, too... And I put one Royal Purple MaxClean in my car recently. I then ran out of gas. >.< Now that wasnt the Royal Purple's fault, it was my fault. THIS TIME, I will put in the Redline SI-1.. because it may work a touch better than the Royal Purple. It also costs $5 less, so, WIN! :) I can't give you MPG differences, but, cars I have used it in, that seem to run smoother EVEN WITH AS LITTLE AS 1oz. PUT IN THE GAS TANK! READ THE DOSING! -YOU ONLY NEED TO PUT IN 1 ounce or so, maybe 3oz to make you feel better but that is maybe a waste, to CLEAN THE FUEL SYSTEM-- - Cars I have used it in, partial list because I honestly do not remember all the cars: 1) 1995 Ford Taurus GL, 3.0L Vulcan, likely was a flood car, 182,000 or so miles. Could me a nice car but this one looked nice and was in good cosmetic condition with cold AC.. but was a piece of **** otherwise. Strike One for Taurus. I also had a 99 Sable that was perfect.. RAN BETTER ON FUEL SYSTEM TREATMENT OF REDLINE, JUST SMOOTHER. YOU CAN NOTICE IT IF YOU ARE TUNED TO HOW THE CARS RUNS BEFORE/AFTER WITH A TRAINED EAR AND A FEEL FOR THE CAR AND SOMETIMES TAKE NOTICE OF HOW THE CAR DRIVES WITH THE RADIO OFF AND HOW IT FEELS AND SHIFTS, PERHAPS. JUST SMOOTHER. SAME WAY WHEN YOU CHANGE OIL OR TIRES. YOU CAN TELL. *Car is gone. 2) 2000 Volvo V70 XC AWD, ~131,000, 2.4L Turbo I5 - SAME. RAN REAL NICE ON THE REDLINE IN THE TANK. *Car is gone. And no, it wasn't the fuel injectors. Made me love and appreciate Volvos and all other finer cars, this car. Or most of. Some finer cars suck lol. Something about driver error... 3) 1993 Chevrolet (get ready for it) "S10 Blazer Tahoe LT." Unknown mileage; engines switched due to issues (?) . RUNS LIKE A DREAM ON REDLINE. RUNS PRETTY GOOD ON GUMOUT TOO BUT REDLINE HAS THE EDGE. *Car is sitting, waiting for work. Going full build with it. 4) 1999 Volvo V70 XC AWD, 168,850 miles, - SAME AS THE YEAR 2000 VERSION. *The Redline is going into this car. 3oz initial treatment, though I only need to put in 1oz.. maybe I will. 5) 2003 GMC Envoy XL. 167,500 miles; 4.2I Vortec 4200. This car is abused by its mechanic, with overpriced brand new tires and 10W-40 motor oil as well as Lucas oil (straight 80 weight....... !!!!!!) when it says 5W-30 on the cap. Think about that. 5W-30 RIGHT ON THE CA.. No, er are going two or three times as thick, and calling it "better." WHAT??????????? Aint 1960 or 1970 anymore... Anyways... RUNS NICE AND SMOOTH ON THE REDLINE. NO OTHER CLEANERS USED. So, there you have it. This is why I will ONLY buy: 1) Gumout at WALMART; It costs less, and is readily available; 2) Royal Purple MaxCLEAN; This is the hardest to justify, as it costs $5 more than SI-1, has perhaps slightly not as good results, and I ran out of gas when I put it in. So I couldnt evaluate it properly.. If it runs out of gas after I put it in a half tank I am going to be a complaining consumer to the BBB but lol that wont happen... I will try that one again too, in time, with money... 3) So far, the best of the three: This Redline SI-1. ^^ This was aimed at some of the posters that leave STUPID reviews! Like "My car ran out of gas. 1 star." These are the "bad review trolls" and they need to be shot and executed by the police in the street in a public forum, like Rome and stuff. These are bad people, these trolls. They need love. And they need Jesus. But notice I am not giving a product a one-star review because I ran out of gas. Take heed, lemmings. :) And, one more thing before I hit "Submit" or "Preview my review:" PEA cleans like dishes in a dishwasher. It breaks down any dirt and stuff in fuel system, and carries it away to combustion. IT DOES NOT CLOG FUEL FILTERS. Now, sure, if your fuel filter is clogged.. Will it carry stuff from it to injectors? NO! Why? because it DISSOLVES IT. Then it goes with fuel flow. So, if using in a dirty system: USE A LOT!! USE the 3 ounces or so! GIVE IT ENOUGH TO DISSOLVE THE DEBRIS AND DIRT YOU EXPECT ARE THERE! Or, better yet, change the fuel filter. It is a little tricky and you must be careful, but on a lot of cars its easy, if its not then again: CLEANER!! :) This product will clean injectors, improve spray patterns, maybe increase VOLUME of fuel to the engine, and clean up "Ethanol poop," gas sucks nowadays, and you are a fool if you are saying that gas doesnt leave the ethanol gummy stuff in its effort to be cheapened for maximum profit, winter-blend gas (the worst,) etc. Ethanol eats rubber and isnt good for fuel systems, so why is it in gas????........... Anyways.. Cleaners DO have a purpose.. Sure, YOUR CAR WILL RUN ON JUST GASOLINE but me myself, I believe in these products that address specific things that were overlooked in the inherent design of "just normal gas delivery." Did you like or dislike my review? I tried to make minimal, or no, typos. Firefox helped by having everything underlined in red that it didnt recognize, and I scanned it twice.. Let me know! :) ... show more
Reviewed in the United States on August 18, 2013 by Joseph Corbisiero
The Best Performing Fuel System Cleaner currently available.
Size: 15 Fl Oz (Pack of 12)
Review Image by Slipstreampilot
Review Image by Slipstreampilot
Redline SI-1 is currently the best fuel system cleaner that is readily available. One of the best examples supporting this statement is represented by the condition of my 2003 S2000's engine. I bought the car new and I'm responsible for essentially every one of the 99,700 miles on the clock. The earlier S2000s (1999-2003 model years - called the AP1) are notorious for oil consumption through the PCV valve (for a number of reasons), and as a consequence the intake manifold and throttle body will typically develop a nasty coat of carbon saturated goop. In contrast - the intake and throttle body of my S2000 could only be cleaner if I steam cleaned them (or ran a water/methanol injection system). I credit this product's use, in conjunction with using a top-shelf synthetic oil (Amsoil) with keeping my engine not only clean, but essentially free of wear. The last leak-down test performed on my engine (at 90,000 miles) showed less the 2% leak-down in all cylinders, and no more than 0.5% difference between all cylinders (1.25, 1.5, 1.5, 1.75 - cylinders 1-4). I do not drive my S2000 conservatively either, as it gets revved to 9000 RPM 2-3 times every time I drive the car - and my car is geared with a 4.44 final drive. Those are essentially 1/8th mile gears, and contribute to higher than normal RPMs in all gears, when compared to a stock S2000 - and significantly more RPMs on average than any conventional street car. To give the proper perspective, the age of an engine is not simply a function of the number of miles driven, but as a function of how many average RPMs the engine turns per unit distance (measured in the engines average RPMs turned per mile driven). This is why (generally) a car with mostly 'highway' miles typically has significantly less engine/drivetrain wear than a car with mostly 'city' miles (and why city driving is considered "severe" driving conditions by most auto manufactures). With this in mind, your average Honda S2000's engine turns 1.5 - 2 times as many RPMs per mile as the average passenger car under 'normal' driving conditions. If an S2000 is driven in a 'spirited' manner - that number can be over 2.5 times the average car. So (for example) imagine a Toyota Camry with less than 2% leak down per cylinder with over 200,000 miles on the clock (essentially an engine that is barely broken in) - that would be amazing, and would give a more effective measure of part of the benefit of this product has provided my S2000. So imagine how much your 3 Series, Camry, Accord, Fusion… ANY gas fueled car would benefit from using SI-1 and a quality synthetic oil? It truly does make a difference. You might ask - "how does a fuel system cleaner reduce wear in an engine?". The full answer is complicated, but the simplified explanation is that the the fuel - more importantly the additives in the fuel - provide upper cylinder lubrication (direct lubrication), and the detergent action in the fuel additives is designed to help prevent and remove carbon deposits in the engine. Deposits due to fuel quality and combustion byproducts are a major source of wear in all engines. Most top-tier fuels (Chevron/Texaco, BP, Shell, Exxon to name a few) collectively established a self-imposed convention to supply higher levels of detergents than required by the government (a form of self-regulation). However, these fuels supplied with almost twice the level of detergents required by the government still do not provide enough detergent and lubrication to keep your engine clean - especially with the levels of ethanol pushed by the corn lobbies. As a result, deposit build-up is still a reality facing car owners. While deposit formation is not immediate in top-tier fuels - and most certainly not nearly as fast as with bottom-of-the-barrel fuels (Citgo, Raceway, Sams Club… etc), it will happen over time. This is where SI-1 shines: it provides outstanding upper-cylinder lubrication and cleaning action - keeping your engine almost analytically clean, and it does this without chemically breaking down your motor oil (in blow-by products). One of the reasons this product works better than products from other quality fuel system cleaner manufactures (such as BG and Chevron), is the fact the SI-1's detergent process is more 'gradual', because it's specifically catalyzed by the heat of combustion - and the cleaning process is not solely reliant on strong chemical solvent action. The main components of SI-1 responsible for it's highly effective cleaning process (as mentioned by several other reviewers) are polyether amines (PEA). BG (44K), Chevron (Techron), and essentially most other fuel system cleaners rely heavily on strong solvents (non-polar solvents, of varying concentration and quality) instead of PEAs to remove carbon and other deposits (even though some of these products use low levels of PEAs in their formulation). While the use of quality solvents can be highly effective (again, dependent on the concentration and quality of the solvents used), the unfortunate side effect can be the premature chemical breakdown of motor oil - which is why most fuel system cleaner manufacturers recommend you use their products the tankful prior to a scheduled oil change. How many people are able or willing to schedule/time the last tank of fuel before a scheduled oil change in their busy lives? Not many. You might have noticed I only mentioned two other capable fuel system cleaners by name (products which I believe are very effective "cleaners"). Their specific mention was deliberate. Other than Redline, BG, and Chevron the only other effective fuel system cleaner that I would recommend to anyone would be the one made by Amsoil (Performance Improver - PI). PI works in a similar manner to Redline's SI-1 and contains PEAs, but I have found Redline's SI-1 to be more effective and economical when compared to Amsoil's PI. The vast majority of other branded fuel system cleaners are essentially "snake oil", using ineffective concentrations or mixtures of solvents and carrier solvents (heavy aromatic naphtha, xylene), heavy petroleum products - and in the worst products, they use heavier alcohols (polar protic solvents) in place of more effective cleaning agents. The use of alcohols and some heavy petroleum products actually does more harm than good and actually creates more deposits. Your car may seemingly run a little better when operating with fuel treated with those products - but the car will rapidly run worse once the product is diluted in the follow-on tanks of gas. What does your average person do then? Buy more and add it to the fuel again (thinking it needs a little more cleaning). The car then runs a little better, but then doesn't (again) when the product is diluted… and I think you get the idea. This vicious cycle doesn't happen with a quality cleaner. SI-1 Usage: The best way to use SI-1 is the way it was originally designed to be used - by titrating (mixing) a specified amount per tank (depending on how much fuel you fill up with). I personally use approximately 1/10-1/4 bottle per 10 gallons - using a higher concentration if my car's engine needs more cleaning (subjective decision), or if I am forced to use a lower-tier gas due to low fuel and few to no other options. The instructions on the bottle recommend using a full bottle every 3,000-5,000 miles or so (like most of the fuel system cleaners available) - but not because of a formulation change. The change from Redline's previous recommended per-tank addition of SI-1 to a 3-5k mile interval was pure marketing - because most people are notoriously lazy and unwilling to add something every fill-up, and Red Line's marketing decided to accommodate those too lazy to titrate. While a bottle every 3-5k miles is not at all a bad choice (I occasionally do this to supplement the per-tank titration method), I don't substitute a 3,000-5,000 mile interval for the much more effective addition of SI-1 in every tank. The main problem with cleaning your fuel system only once per 3,000-5,000 miles is the fact carbon and other deposits build up over the interval between clean-ups - and that build-up increases wear over that time. If you're running a conventional or cheap synthetic oil - that increased wear is happening just as your oil is breaking down, compounding the wear problems. Furthermore, treating one tank-full of fuel with your chosen fuel system cleaner once every 3,000-5,000 miles will not get rid of all the cumulative build-up, and the following interval between clean-ups will accumulate more deposits than the interval before the last (and so on). SI-1 keeps my S2000's engine constantly clean as it is driven, and build-up (and wear) has never been a problem. Using SI-1 in conjunction with using a quality synthetic oil (such as Amsoil) is the best way to ensure long life and flawless operation of your (gas powered) vehicle's engine. ... show more
Reviewed in the United States on July 14, 2015 by Slipstreampilot
Nectar of the Gods!
Size: 15 Fl Oz (Pack of 2)
This fuel additive is grea for Gasoline Direct Injection (GDI) and turbocharged vehicles that suffer from rapid carbon buildup. It’s formulated with Polyetheramine (PEA), which is widely recognized as the most potent detergent available for dissolving stubborn engine carbon deposits—and has one of the highest concentrations of PEA on the market. PEA possesses the extreme thermal stability required to survive the intense heat of the combustion chamber. This allows it to break down and cleanly burn off deposits clinging to fuel injectors, intake valves, piston crowns, and cylinder heads. If a fuel system/injector cleaner doesn’t contain PEA, it’s useless against carbon deposits. It smooths rough idling, engine shuddering, and hesitation during acceleration and restores proper fuel injector spray patterns to optimize the air-fuel mixture to maximize gas mileage and reduce fuel blowby and oil dilution. It also contains a synthetic upper cylinder lubricant that leaves a protective film on the upper cylinder walls, valve stems, and upper piston areas which reduces wear, improves ring seal and contributes to a quieter, smoother idle and more efficient engine performance. Pour it into your gas tank before a fill-up then just drive as normal—although I find it’s slightly more effective to use on an extended highway trip when the engine experiences sustained use at full operating temperature. I’ve used it in two consecutive tanks as a first “shock treatment,” then again 300 miles before each oil change. It’s safe to use as much as every 3,000-5,000 miles, If you prefer continuous protection, you can add a smaller maintenance dose of 1.5 to 2 ounces per 10 gallons of fuel at every fill-up. Highly recommended! ... show more
Reviewed in the United States on September 23, 2026 by Plusmind
Prolong the life of your Car!
Size: 15 Fl Oz (Pack of 1)
This is my 2nd or 3rd time purchasing this Red Line® SI-1 complete fuel injector cleaner and I have been super pleased with the results. I have noticed better gas mileage and easier shifting in the engine. My engine noise or vibration depreciated after utilizing this product. I believe it's worth its weight in gold to help future problems from existing in your vehicle. So, every once in awhile, say after each oil change, I would suggest using this product as a preventative measure to prolong the life of your vehicle and complications that could arise. ... show more
Reviewed in the United States on September 12, 2026 by Brandon C
Spendy but it works
Size: 15 Fl Oz (Pack of 2)
Cleans the fuel system well. Only wish it was more affordable.
Reviewed in the United States on October 4, 2026 by Brian
Excellent and now I have it on automatic reorder
Size: 15 Fl Oz (Pack of 1)
I purchased the Red Line SI-1 Complete Fuel System Cleaner for my Nissan Rogue, and I’m happy with my choice. It’s easy to use and a great addition to regular vehicle maintenance. I like that it helps clean the fuel injectors and fuel system to support smooth engine performance. Red Line is a trusted brand, and this product gives me extra peace of mind when it comes to taking care of my vehicle. Great value for the money, and I would definitely recommend it to other Nissan Rogue owners! ... show more
Reviewed in the United States on October 10, 2026 by Trent Tweddle
My engine is as good as it was
Size: 15 Fl oz (Pack of 4)
Okay I am writing this for those who keep their cars longer than 2 years: This is the good stuff. It has more PEA in it than any other fuel additive. PEA is the stuff that Chevron developed to clean engine on a molecular level. It's pricey, but you get what you pay for. And then maybe not if you buy the cheaper snake oil. If your car is running on LP then you can skip it. Oh! one more thing to consider. I am getting between 44 and 47 mpg on the highway . . . of course. ... show more
Reviewed in the United States on August 27, 2026 by Audiomook
Keep your engine running smoothly for years to come
Size: 15 Fl Oz (Pack of 1)
I’ve been using this product for years now and it makes such a difference on the way my engine and fuel system runs. The product comes neatly packaged in a clear plastic bottle and is a pleasant size that doesn’t leak and looks great. It’s completely effective for its intended purpose which is to keep your engine running smoothly and to clean every possible part of your fuel system. If you’re looking for durability in keeping your engine running properly and maintaining the vehicle for a long period of time, this should be part of your routine maintenance plan. Just follow the directions on the bottle. ... show more
Reviewed in the United States on September 4, 2026 by Tripod
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