Customer Ratings & Reviews

Fuel Mileage increase is noticeable. Lasts a few tanks after.

I always use this on my last empty tank 20 gal fill-up before changing my 2013 Silverado 6.0 gasser's oil. I also use it along with the Upper Cylinder Lubricant too at the same time with good results. I definitely notice my truck running smoother for a pretty good long while afterwards. Give it a shot!

As the product cleans during the tank of gas usage, gradual improvement in performance is noted and definitely is noticeable after running the entire tank of additive containing fuel through. I haven't calculated the actual mpg increase, but it has definitely helped.

Great value for a product that works as advertised.

Car runs 100% better starts instantly in cold weather improved mileage

I couldn't believe how quickly I noticed a difference in performance in less than 100 miles smoother,stronger on a 160k plus Corolla

The AMSOIL Performance Improver Gasoline Additive has improved my gas mileage and keeps the engine running smooth. I use that in between using the Upper Engine Lubricant. I would recommend these products for any vehicle.

Bought a 12 pack, started adding 1 every fill up, checked mileage before and after, maybe 1/2 mile per gallon better. For the cost per bottle, doesn’t justify 1/2 mile per gallon. Sorry….

Dose a great job for cleaning out an engine that has carbon build up problems. Helps with fuel economy a lot also.

Put this in my 2016 Honda Pilot Touring and it seemed to make my Pilot run smoother. It could be a Plasibo effect but I never got the same feeling when using another brand Seafoam.

Use all your products for my car

Use 1 bottle in all our 5 vehicles 2 times a year and have noticed slightly better mileage and drivability. Great product at a very reasonable price.

So important to use before an oil change. Especially for the GMs that are direct injected. Treat yourself don’t cheat yourself.

I added this to my stock style radiator for my classic muscle car. It lowered the coolant temperature dramatically in the heat of the Florida sun in the summer. I would run at 210° now I barely make it to 190 on average I’m hovering right at my thermostat which is 185. The car runs amazingly well

I have to admit I've tried a lot of fully synthetic oil but AMS oil is second to none I highly recommend it you can feel the difference you can feel the power for my 2007 Chevy Silverado 1500 classic

Je synchronise ce traitement avec mes changements d'huile. On sent vraiment la différence!

Yes it works!!! I've got nothing bad to say about it other than it's a bit pricey in my opinion.

Like the title says, I’ve been using this in my daily driver…a VW Golf R that I put roughly 30k miles on per year. Since I’ve been using this on every other tank, my car has been averaging an extra 2-3 mpg versus without.

AMSOIL was recommended to me by family. I tried AMSOil in 1 of my vehicles and immediately noticed a performance improvement in response, idle, fuel economy, and noise reduction due to the engine having to work less to operate. Since trying AMSOil in August, I immediately signed up for their membership, moved all my vehicles lubricants over to AMSOIL, follow their maintenance schedule to spec, use their Upper Cylinder Lubricant on every fill up and exclusively use their products. Save time & Money, AMSOIL is the way to go.

Helped my PowerWagon get an extra 2 mpg on highway I’ll take it.