This is a great cleaner, my car run so much nicer. I do believe my gas mileage has improved also. Great value for your money. I definitely recommend this product.

I can't be sure fuel system cleaner does anything but I use it because my car manufacturer recommends it at every oil change. Many gas pumps will now add this for you when you fill up (at various price points depending on concentration).

I've done research on it in the past and the ingredient that's apparently most effective is something called PEA (polyether-amine). The more of this a fuel system cleaner has the more expensive the fuel system cleaner seems to be (there are many brands). I've used a product called Techron in the past based on many positive reviews. It costs less per ounce but requires more so this product is actually cheaper to use.

My only issue with this fuel system cleaner is that I could not find what is in it. This is not detailed anywhere. Let's face it, we pour these products into our car and hope they do what they claim. Short of taking your motor apart you'll never really know so the manufacturer should show us some proof of value.

I'm giving this 4 stars because it's good bang for your buck since it treat 90 gallons even at the highest recommended concentration, that's 3 to 6 tanks of gas depending on the type of car/truck you have. But the company should include something on its chemical makeup on its website to at least give use some clue what we're buying.

Reviewing this product is difficult, because unless you're an auto mechanic, it is difficult to determine if the cleaner is actually working. I'm not an auto mechanic, so I'll stick to what I know. Per the directions, I added 3 ounces to 15 gallons of fuel and drove for the next week until my tank was almost empty. I did not see an increase in fuel efficiency (i.e., increased mileage). My car did not run any better, and it still idled at around 850 RPM. I drive a car that's 16 years old and has 160K miles. It's a stick shift and still in great shape. I have a newer, more modern car, but I drive this one daily because driving a stick means you actually have to pay attention to every aspect of driving, and I love it.

I almost always use a gas additive when I fill the tank, but I was hoping to get one to two more miles per gallon with this additive. I'll sum this review up by saying this additive performs about the same as the Lucas Upper Cylinder Lubricant & Fuel Injector Cleaner that I normally use. It just takes a lot less of this cleaner to do the same thing (3 ounces vs. 5.2 ounces). However, I can get more uses per dollar spent with this one versus the other cleaner, and that's enough for me to continue using it.

WATER IN MY GAS TANK NOT DONE YET USING IT . mY GAS IS TILL RUNNING IT THROUGH BUT, I LIKE THE WAY IT RUNS MY CAR RUNS BETTER NOW . THE SMELL IS STRONG NOT CRAZY ABOUT THAT . IT IS A GOOD PRODUCT .

There's a lot of automotive snake oil out there - and candidly, I can't tell if this is in that category. I fastidiously maintain my cars - so I use fuel additives at every oil change to keep the injectors clean and fuel lines from corroding. I decided to try this concentrate on my 1999 QX4 with 175,000 miles. It seems to be no different from the Techron I used to add - which is a plus since this is about 90% cheaper. The proof, however, is in the eating - and it will be months to years before I can genuinely assess it. The good news is that with 16 ounces and one treatment every 2500 miles, I have between here and 200,000 miles to assess the results - and at under $20, it is tough to beat.