What to do if your bottles don't fit BOB
When the BOB was designed in 1992, all motor oil bottles had the same neck diameter of 1-1/4 inches. Then, Mobil One, Castrol Syntec, and some others came up with new designs that were bigger than the BOB receptacle. Weíve considered producing adapters to accommodate these bottles, but that would just be an added expense for you, our valued customers. So, hereís a method to make your own adapters for bottles that donít fit or wonít stay in the BOB trough. Itís simple, and best of all, itís free!
Mobil 1 Adapter
Obtain some old oil bottles that have 1-1/4 inch necks, like Chevron, Amoco, Texaco, or others. (House brands usually have a good bottle.) Using a razor knife (be careful!), cut off the tops of the bottles to the dimension shown above. We donít recommend using a saw, since the little bits of plastic will contaminate your oil. Put these adapters into the trough and put your Mobil One or other big necked bottle into the adapter.
We've been in contact with the Mobil and Castrol people responsible for the large necked bottles, which really negate the whole advantage of plastic bottles, that being the ability to pour into an engine without the need for a funnel. The large necks are European styles, so these manufacturers are just trying to be stylish, without regard for functionality.
The original bottle designed for use in the United States is the small 1-1/4 inch neck. One of the people who designed the small necked bottle told me they designed it specifically so it would fit inside the filler on most American cars. Nobody can really figure why Mobil and Castrol went to the big necks for American markets in the first place, since they don't fit American cars. The consensus is that the extra cost of the product requires a different, more expensive, container.  If you have any comments you'd like to have forwarded to Mobil or Castrol, send me an email, and I'll make sure they get it.
Gerard Forgnone, Inventor of BOB
Questions? Comments?

Click here to email Gerard

Return to main page

Contact Mobil about their large mouth bottle:

Call 1-800-662-4525

or visit

Mobil One Website

All photographs and content on this website are copyrighted by the author. Unauthorized reproduction is strictly prohibited!