CV's have a hard life, especially the inboard CV's; aft of the engine, some are directly above the exhaust (914 guys). Cheap grease will turn to clay from the heat.
Grease is not expensive but the job is downright unpleasant so you don't want to be doing it any more often than you need to. Couple that with hard-to-replace CV's and the result is; use good grease... Enter "Lubro Moly LM47"
Note: These are 100g tubes. That is roughly 3.5 ounces. The factory manual recommends 90g (3.1 oz.) for the 914 and (this one's odd) 70g (2.5 oz.) for the 914-6 and a 911 joint. If you're going by that you'll need 4 tubes for the 914 and 3 for a 914-6 or 911. The reason we think that is odd is because the 914-6 joint is the exact same size as the 914 joint and... the 911 joint is much larger! Here's what we do... 1 tube per CV. It works perfect.