they are similar in that they are both pretty mild on the Meguiar's scale.
But they are different in that FG is best applied by machine, it does contain some carnauba and its a little hard to remove if you use too much product. It leaves the surface very smooth when done. Cost is only $9/16oz.
#81 is applied by hand, contains no carnauba, leaves a squeaky finish when done (ala Zymol HD Cleanse) and is very easy to remove even if you use too much product. Cost is around $18/32oz.
Both are very good and both need a final wax to seal in the oils.
