OH MAN, DON'T EVEN GET ME STARTED ON THIS SUBJECT!!!!
To start with, those of you who have no problems with leaking containers consider yourself lucky.
I have been using Amsoil products for about 4 yrs now. I have used thier diesel fuel additives for 4 yrs and EVERY time I've recieved the cetane boost it has leaked. No, and I repeat NO damaged to the box from UPS. Every time I've got a shipment with cetane boost I have been greeted by its god awful odor and the UPS man griping about the smell. I have called and E-mailed Amsoil several times on this and even suggested they ditch the metal cans because the little metal plug does NOT seal. I said they need to package it in a container with a foil top seal and preferably a plastic container. They said it had to be in a metal can because the Cetane boost product would break-down plastic. I told them then why does everyone else use plastic containers? I said I mix 1 can of the diesel concentrate and 1 can of the cetane boost in an old qt container from when I used Cummins injector cleaner, and have been doing this for 3 plus years and NO problems with the Cummins plastic jug degrading, etc. I also mentioned their containers need longer necks so you can pour the stuff in a pickup truck fuel tank without having it run down the side of the truck and a little clear plastic panel with oz markings would be nice so you could actually measure how much you are dumping in would be nice.
Well I guess someone finally took note becasue the last cetane boost I recieved came in a black plastic bottle with a foil seal. And best of all I DID NOT LEAK!!!

The new bottle still has a short stubby neck which will most likely cause some to run down the side of the truck

and still no markings or way of measuring out how much you have poured in the tank (yes I know you can get a measuring cup from the kitchen, but it is messy and still ends up on the side of the truck when tring to pour from the measuring cup into the tank). Anyway I guess it is a start
About half the time when ordering oil or anything else I have a leak because a cap is loose. This last shipment I ordered the PI gasoline additive (for the car) and one of the containers had a hole. There was NO visible UPS damage to the box. So I'd say Amsoil has either a packaging or quality control issue. Kind of sad considering how much thier products cost the consumer.
My final beef with Amsoil is I have ordered a dual remote bypass unit. Since I ordered CPFF's stuff I opted to not purchase the whole kit from Amsoil, but just the individual pieces. Well the main part (the filter mounting assembly you put the filters on) has been damaged. They have me 2 units and each has gouges on the surface where the oil and bypass filter seals contact the filter assembly. This damage is occuring somewhere in the manufacturing process becasue it happens before the unit is painted. This has turned into a 2 month ordeal tring to get things "right" by me. Just to show you how great Amsoil customer service is... . I have had to make almost all the phone calls to resolve matters, they seldom return a call. I'm so ****** and gesgusted with Amsoil I told them I wanted a refund and the 2nd damaged unit has been sitting in my living room for over a month waiting for UPS to come get it (they have supposedly "looked into this" twice now) They tell me if I want a refund I have to pay to send it all back plus I won't be refunded the original shipping charges either!!! I said so now you want me to pay to send you back your damaged equipment? They said they would be glad to send another replacement, but if I wanted a refund then I eat the shipping costs!!! WHAT A BUNCH OF BS!!! I last talked to tech services and the sales manager over a week ago, they where going to "do some calling and get back to me", well I'm still waiting!! Supposedly Amsoil has shipped me 2 other filter assemblies to replace the one sitting in my living room, well I guess they got lost somewhere. My suspicion is as soon as I hang up the phone they forget about me and don't bother putting out any effort. Something is not right here..... Amsoil was more than happy to take my money, but are jerking me around for resolving this matter to my satisfation. Am I wrong for wanting a full refund of every penny I paid and not wanting to eat the shipping costs????
Sorry for the long venting, but Amsoil may very soon no longer be getting my business nor my recommending them to others.