lkchris
Active member
The other issue that came up with this tech was that 'most so called 'synthetic' oils are not really fully synthetic, while this Motul 4T 7100 is completely, 100% synthetic. In fact, that 5-40 expensive BMW oil may be one of them not completely synthetic.
BMW 5W-40 is grade "ultimate" which means fully synthetic.
BMW 15W-50 is grade "pro" which means semisynthetic.