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STP Octane Booster, Bottled Fuel System Cleaner Restores Lost Power and Acceleration, 5.25 Oz, STP

4.6 4.6 out of 5 stars 1,038 ratings
$3.97 with 50 percent savings
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Purchase options and add-ons

  • Boosts octane
  • Reduces knocking and pinging
  • Helps restore performance
› See more product details

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STP Octane Booster, Bottled Fuel System Cleaner Restores Lost Power and Acceleration, 5.25 Oz, STP
$3.97
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STP Ultra 5 In 1 Fuel System Cleaner and Stabilizer, Deep Cleans Fuel System and Fights Engine Friction, 12 FlOz
$18.79 ($1.57/Fl Oz)
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STP Complete Fuel System Cleaner, Fuel Cleaner Deep Cleans Entire Fuel System, 5.25 Oz, Multicoloured, 1 Count (Pack of 1)
$5.97
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From the manufacturer

About Us

In October 1954, three businessmen with a mere 3,000 dollars in start-up capital introduced the first STP product in St. Joseph, MO. STP, began with one product — STP Oil Treatment. It helped automobile motor oil resist thinning at high temperatures and pressures.

Product Description

This two-in-one formula boosts octane and cleans the fuel intake system to restore lost performance.

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STP Octane Booster, Bottled Fuel System Cleaner Restores Lost Power and Acceleration, 5.25 Oz, STP

STP Octane Booster, Bottled Fuel System Cleaner Restores Lost Power and Acceleration, 5.25 Oz, STP

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What's in the box

  • STP Auto Performance Aid

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    Price-50% $3.97
    List: $7.99    		$11.39$47.64$12.98$4.22$32.99
    Delivery
    Get it as soon as Thursday, May 16
    Get it as soon as Thursday, May 16
    —
    Get it as soon as Thursday, May 16
    Get it as soon as Thursday, May 16
    Get it as soon as Friday, May 17
    Customer Ratings
    4.64.6 out of 5 stars1,038
    4.54.5 out of 5 stars47
    4.64.6 out of 5 stars1,021
    4.84.8 out of 5 stars19,508
    4.74.7 out of 5 stars4,872
    4.64.6 out of 5 stars729
    Value for money
    4.1
    4.8
    4.1
    4.6
    4.7
    4.2
    Mileage
    4.0
    4.6
    4.2
    4.5
    4.6
    4.1
    Easy to use
    4.2
    —
    4.8
    4.8
    4.7
    4.7
    Sold By
    Amazon.com
    Amazon.com
    1185 Corp
    Amazon.com
    Amazon.com
    Specialty Products Intl

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    Customer reviews

    4.6 out of 5 stars
    4.6 out of 5
    1,038 global ratings

    Customers say

    Customers like the quality, performance, and value of the car adapter. For example, they mention it works well, gets better mileage, and saves money at the pump.

    AI-generated from the text of customer reviews

    27 customers mention24 positive3 negative

    Customers like the quality of the auto accessory. They say it works well for small engines, and is worthy for their engine. Some say it runs a lot better, and works in conjunction with a fuel system cleaner to keep their fuel system clean.

    "Works well and really peps up my engine!!!" Read more

    "The product itself works well for my truck, but don’t buy these online...." Read more

    "...getting true 2-for-1 benefits with the boost of octane and keeping my fuel system clean...." Read more

    "...I know this stuff wasn't made for small engines but it does a great job and fixing the cheap s***** gas we have now." Read more

    25 customers mention22 positive3 negative

    Customers like the performance of the auto accessory. They say it runs better, gets better mileage, and substantial increases mpg. They also mention that it has better throttle response in 4th and 5th gears, and helps speed up their vehicles. Customers have never noticed any performance lag with this product, and it keeps their car running like a dream.

    "...engines can benefit from this as it leads to increased efficiency of combustion...." Read more

    "Works well and really peps up my engine!!!" Read more

    "I've only driven a few miles with it. It has definitely improved engine responsiveness...." Read more

    "...I definitely notice better throttle response in 4th and 5th gears...." Read more

    11 customers mention8 positive3 negative

    Customers like the value of the auto accessory. They say it saves them money by not filling up every seven days to now every ten days.

    "...Plus it's way less expensive than buying premium fuel which may or may not help with cleaning...." Read more

    "...Actually it increases it enough that the product SAVES me money...." Read more

    "...They are low quality and not worth it." Read more

    "Definitely worth the price, noticeable difference in response and speed, I have a 1987 BMW 325 with M20B27 engine with Turner/Conforti performance..." Read more

    5 customers mention0 positive5 negative

    Customers are dissatisfied with the leakage of the auto accessory. They mention that the seal in the bottle came loose, the seal was not good under the cap, and it evaporated in the box.

    "I ordered 3 bottles to help when towing and one arrived leaking. Seal was not good under the cap. Leaked all over the box and other two bottles." Read more

    "...There is something up with how these are sealed, as they slightly leak when in transport...." Read more

    "Not sure if it works. The bottle leaked and evaporated in the box. Past the return period so SOL." Read more

    "Product was already open due to the seal in the bottle coming loose...." Read more

    Leaked
    3 Stars
    Leaked
    I ordered 3 bottles to help when towing and one arrived leaking. Seal was not good under the cap. Leaked all over the box and other two bottles.
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    Top reviews from the United States

    shiloh111xxx
    5.0 out of 5 stars Wonderful product!
    Reviewed in the United States on April 13, 2024
    Size: 5.25 Fl Oz (Pack of 1)Verified Purchase
    Works well and really peps up my engine!!!
    Helpful
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    Snake Plissken
    5.0 out of 5 stars This will NOT increase hp, torque, or speed
    Reviewed in the United States on December 26, 2022
    Size: 5.25 Fl Oz (Pack of 1)Verified Purchase
    Do not buy this if you are thinking it will improve your vehicle's performance in some way. I made that mistake of ignorance myself when first grabbing a bottle off the gas station shelf. It likely won't hurt your engine to use one bottle per 15 gallons (they say up to 20), but it's just not what most people think it is/does. **edit*- this DID cause transmission damage, knocks, and pings on my naturally aspirated system. I mistakenly thought that my variable octane (87-93) engine and drive train could handle this change in octane. This was my mistake, I was wrong, and this shouldn't be used on a naturally aspirated engine unless the gas has been sitting for ~6 months and has gone stale. Check with your dealer about your specific vehicle make & model.*

    Octane boosters raise the octane level of your fuel, making it MORE difficult for gasoline to combust under pressure. They get a bad rap as they're sold as performance enhancers, or speed boosters. High-revving, high psi turbo/supercharged engines can benefit from this as it leads to increased efficiency of combustion. High-octane fuel requiring performance cars that only have access to 87 octane gas stations, or fuel that's been sitting around a few months or more can benefit from this too. You can do some research yourself, but if your vehicle does not specifically recommend using an octane booster or a fuel with octane higher than 91 or 93, then it's likely not for you. Maybe if you only have access to low octane gas, but this is an expensive way to boost it by only a little. You're way better off using 93, or 91 octane as your car will take. Using with regular gas if your car takes regular 87 octane gas will do nothing.

    I use it in a naturally aspirated 3.8L V6 with 104k miles and it was what was causing me knocks around 3rd gear.

    Typically a fuel system cleaner (and this part is important!) which SPECIFICALLY lists the detergent levels, not just the name of the chemical the detergent used, is a better bet for increasing performance, but still only by a few hp in the best of scenarios on the oldest of cars in the worst of shape over a long time after a lot of uses, and typically is only around up to 0.5hp. This one doesn't even list the detergent I don't think, just that it has 'jet fuel' whatever tf that actually is. It's not fuel for a jet, that's for sure (kerosine is what jet fuel actually is).

    There are way way better options for boosting performance, and I'm not sure how this would handle in a system that can't take varying levels of octane. Snake oil for many, but it does have it's uses and works for some very specific cases and again, it does not make sense to me yet why. I have some unknown issue, in a 3-year-old car with a ton of miles for the years, which can take variable octane fuels. I likely have some hairline crack in my fuel system somewhere leaking vapor or letting moisture in. **edit*- it was this octane booster which was contributing to my tranmission knocking issue. After stopping use and going down in fuel grade for a month, it's running like new again.*
    26 people found this helpful
    Helpful
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    A Buyer
    4.0 out of 5 stars I Tried It
    Reviewed in the United States on April 5, 2024
    Size: 5.25 Fl Oz (Pack of 1)Verified Purchase
    I've only driven a few miles with it. It has definitely improved engine responsiveness. I have a long road trip coming up and hoping it will improve mileage such that it extends the distance btw gas station stops.
    Helpful
     Report
    Eric J. Thornton
    5.0 out of 5 stars Totally Worth It!
    Reviewed in the United States on June 23, 2018
    Size: 5.25 Fl Oz (Pack of 1)Verified Purchase
    I wanted to take advantage of the added benefits of my Mustang running higher octane. Even though it can take your typical 87 gas, the torque curve is better with the added octane according to the owner's manual.

    Not sure if I noticed much of a difference at first but after my 6th or so application I certainly did. So I bought a case and now I do the monthly subscription. I definitely notice better throttle response in 4th and 5th gears. It's like she's ready to roar and what a great feeling it is when the gas peddle is that touchy in a muscle car.

    I think the cleaning properties took a little time to do their thing and is why I'm feeling the pep. I am a big believer in adding gas treatments every oil change to counter the crap that goes through your injectors. I don't trust gas with ethanol which attracts moisture and causes corrosion.

    With this product I'm getting true 2-for-1 benefits with the boost of octane and keeping my fuel system clean. Plus it's way less expensive than buying premium fuel which may or may not help with cleaning. This is a no-brainer-must-have product for anyone who needs or is able to take advantage the added octane.

    Only drawback is it is unknown how many points of octane is adds. It should advertise that is adds X per 10 gallons, etc.
    21 people found this helpful
    Helpful
     Report
    Horst Enthusiast
    5.0 out of 5 stars More power! Less mileage because it's too much fun.
    Reviewed in the United States on September 16, 2023
    Size: 5.25 Fl Oz (Pack of 1)Verified Purchase
    First and foremost, your engine needs a knock sensor to get any benefit from this. If it's not a performance car, it's probably tuned for 87 and may run worse if you add this. If you don't know whether it has a knock sensor, Google it.

    I added it to a tank of 91 octane gas, and my engine immediately responded with more torque. It was noticable. Not like adding a supercharger, but you can tell it's pushing a few more pound-feet of torque.

    I suppose this could boost mileage, but it just makes it so much fun to floor the accelerator...

    I will say that if I go on the freeway and reset the counter, and there's not much traffic, it'll read 35MPG with the air conditioning on all the way until I exit, even if that's 50 miles later. This is in a heavy Acura TL-S with a 3.5L V6. That might be two or three higher than usual. As for city driving, it's worse because, again, it just invites me to accelerate more quickly. Someone with a gentler touch might get better city mileage than me. Hard to say. I make mostly short trips on surface streets, so my mileage is going to be awful most of the time.
    2 people found this helpful
    Helpful
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    Robin Yancey
    5.0 out of 5 stars It will fix cheap gas
    Reviewed in the United States on August 14, 2022
    Size: 5.25 Fl Oz (Pack of 1)Verified Purchase
    Bought this for two reasons number one to fix a cheap Chinese scooter did the job perfectly. Better gas mileage more horsepower it ran a lot better. Number two to add a little bit to the fuel for a push mower. Completely and utterly cleaned out the carburetor after a couple of minutes of running it had a lot of white smoke come out lasted about 15 seconds after that the lawn mower was perfect completely clean the carburetor fuel system everything. Put about an ounce of this in a 2 1/2 gallon fuel can. Haven't had a problem sense starts first pull. I know this stuff wasn't made for small engines but it does a great job and fixing the cheap s***** gas we have now.
    5 people found this helpful
    Helpful
     Report
    Arlo B.
    5.0 out of 5 stars Absolutely great
    Reviewed in the United States on January 17, 2024
    Size: 5.25 Fl Oz (Pack of 2)Verified Purchase
    I get like an extra 30 miles per full tank i also put 91 in my tank was getting like 310 now i get about 340 worth it
    Helpful
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    Ben
    3.0 out of 5 stars Leak in transport
    Reviewed in the United States on October 6, 2023
    Size: 5.25 Fl Oz (Pack of 1)Verified Purchase
    The product itself works well for my truck, but don’t buy these online. There is something up with how these are sealed, as they slightly leak when in transport. I thought it was a fluke a first, but a second go confirmed it. It’s not a standing about of liquid, but enough to make the whole inside of the box smell like it. If you want to use this stuff, buy it from a physical location and not on Amazon
    2 people found this helpful
    Helpful
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    Top reviews from other countries

    DONALD GAUTIER
    5.0 out of 5 stars Fast delivery smooth transaction
    Reviewed in Canada on April 6, 2024
    Size: 5.25 Fl Oz (Pack of 1)Verified Purchase
    Product as described
    Report