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

Works well. Arrived perfectly.

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.*

I love this product easy to use great quality product that I use on ever oil change.

This product allows my VW 2.0L turbo engine to perform with 87 octane fuel as well as 93 octane does.

works great. been using for many years. excellent value

Great to just give a boost to your fuel system. I have an older truck, and I use one of these every time i fuel up just to give it that little extra.

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.

Misleading image. Says treats 21 gallons of fuel. Actual bottle received. 15 gallons. the main image shown says 21. They should update the main image used. Will be using with less full tank than actually thought.