[Turkeybaster115]

There are too many threads these days that start off with civil discussion or question about engine oils, but end up with someone trying to force their opinion of so-called "BMW approved oils" down the OP's throat. These claims are then backed up by warranty threats. Legally speaking, in the US, here is the official stance on any car manufacturer, and ANY type of fluid:

"Vehicle manufacturers are restricted
by federal law from including the requirement of the use of a specific brand or trade name of product or service
as a condition of their warranty. The following is an extract from the Federal Trade Commission’s web site on
interpretation of the Magnuson-Moss Warranty Act:
"Tie-In Sales" Provisions Generally, tie-in sales provisions are not allowed. Such a
provision would require a purchaser of the warranted product to buy an item or service from a
particular company to use with the warranted product in order to be eligible to receive a
remedy under the warranty. The following are examples of prohibited tie-in sales provisions.
In order to keep your new Plenum Brand Vacuum Cleaner warranty in
effect, you must use genuine Plenum Brand Filter Bags. Failure to have
scheduled maintenance performed, at your expense, by the Great American
Maintenance Company, Inc., voids this warranty."