Customer Ratings & Reviews

I Run Premium fuel in my 2022 RAM 1500 the upper cylinder lubricate you are supposed to use it in every tank. I do believe that it works as it should use it every second tank fill. The long neck really helps with the capless fuel cap. I would recommend this.

I use it once a month to give my engine extra protection. I have 150,000 km on it and my engine stays as quiet as a brand new car.

run this every second fill up engine runs amazing , smooth, and better fuel economy

I purchased three products from AMSOIL, The Upper Cylinder Lubricant Corrosion Inhibitor, The DOMINATOR® Octane Boost, and The P.i.® Performance Improver Gasoline Additive I added all three to a full tank but, prior to doing this, I had filled the tank with Top Tier Fuel for this test Shortly after I took a ride, at first, I noticed nothing, but the very next day I put twenty miles on her, and that is when I noticed she ran quieter, and that the pick-up was back I highly recommend this product for older vehicles, and I want you to know, that these products are not a gimmick Check it out for yourself

Increase MPG when added. I usually add in once per month, but it seems to have a positive effect on MPG for at least 2 or 3 tanks. I put in all 3 of my vehicles.

Helped with idle along with PI additive

Keeps my vehicle running great

If you do a little research into Cafe standards and what is missing in fuel you will want to use this. Not all fuel has the amount of needed additives for today's direct injection engines, you want to keep those injectors clean and the rest of the upper cylinder too. I have a 2.4 cylinder turbo boxer engine 2025 Subaru, it really needs this. In practice terms I see a bit more pep in my step with this but not as much as with Amsoil P.I. I think every task is too much but every other tank should be just fine as I only allow a tank to go to 1/4 full and then refill. The bottle handles more than my tank holds so should be good to go.

Helps quiet the noisy GM lifters. Helps smooth out the ride. Just as good as the in-store 30 buck cleaners.

This product is added at every fill up. I also use the AMSOIL P.i.® Performance Improver Gasoline Additive at the recommended intervals. After a short time you will notice a huge improvement in performance! If your engine uses direct fuel injection, which can cause a Carbon buildup, you have to try it!

I use this at every oil change. Does the job.

This product used with every tank of top tier gasoline combined with PI Performance (every oil change) makes me confident my 23 4runner will always be in tip top condition.

Great product, love recommending it.

Im very satisfied with the upper cylinder lubricant . I use in my 2020 Qx60, 2010 GMC Sierra and my favorite 2011 Nissan Maxima . Totally satisfied with results thus. Car notes not in my future.

I started using this product about 4 tanks of gas ago. It cannot be hurting, but I’ve noticed no loss or improvement in mpg.

I use upper cylinder in between using P.I. on our vehicles. it helps to just keep things internally cleaned. its a small price to pay for a little added cleaning. its easy to use just dump it in while putting rewards codes and credit cards in gas pump and then fill up after it.

We have three vehicles I maintain. Part of our maintenance is Amsoil upper cylinder Lube - every fill up. One 6 ounce bottle treats up to 25 gallons. Our vehicles have fuel tanks ranging from 15 to 18 gallons. We generally refuel at 1/4 tank. Lets call that around 12-13 gallons. I see no value added double dosing. This product needs to be made in 4 ounce size. Love the product. I believe it is effective. I just hate the package.

Have been using this additive for all my vehicles by far the best fuel treatment around, my 2007 GMC Sierra just passed 210,000 miles and runs like a Top A+++

I can say I can't tell using it but I hope it's working. I will say they need a easy tear top on it as it's a pain to get off as is. That's why the 4 star.

This is a must fuel additive at every fill due to the "oil dry" area of the upper cylinders. The only time I would not use it is when running a PFI based cleaning additive.