I have a 2007 Volvo V50 with 175k miles and would like to know if the Ceratec or MoS2 is a better option during the oil change? Is there any added benefit to using the Ceratec for the initial oil change then the MoS2 during the interval changes up to 25k?

You have the right idea, first you would add the Ceratec, then at the next oil change use MoS2 instead for every proceeding oil change up to 25k. Thank you for your question.

Do I subtract the recommended amount of motor oil to account for the 300 mL of Liqui Moly MoS2 Anti-Friction?

Yes, you'll want to add slightly less oil to account for the additional 300ml.

Hi, is it ok to mix this with the Liquid Moly Hydraulic Lifter Additive? If so, should I add a a 300ml can and a half of each product to a 2005 X5 4.4 V8? I ordered 2 cans of each to add to my engine on my next oil change. Thanks for your time and help.

Yes, it can be mixed.

Is Ceratec or MoS2 better for blowby?

It would depend on the amount of blowby. Ceratec and MoS2 are anti-friction additives. They are not going to have a major affect on reducing large amounts of blowby.

Is the Ceratec better than the MOS2 for a 2000 Volvo S80 2.9L Non-Turbo for a 200,000 mile possibly worn engine?

Both are really great products however I'd recommend the Ceratec.

what is the difference between Ceratec and MOS2 as it has been recommended by Liquimoly customer service for me to use the MOS2 after I do an engine flush on my 2006 BMW 330i with 252000 miles on it and is burning excessive oil?

The primary difference between MoS2 and Ceratec is primarily centered around it's service life. MoS2 is an instantaneous product that helps reduce friction between surfaces in the engine. Ceratec lasts a longer period of time and creates a coating/fills in scratches in the metal. The primary cause for high oil consumption is due to piston ring wear/poor seating of the oil control ring. This could be due to carbon build up or simply wear and tear of the engine. MoS2 may help reduce oil consumption but if the engine is thoroughly worn out and has a lot of blowby there isn't any type of product that will really solve the problem. It's all going to be dependent upon the overall health of the engine.

Could you theoretically use this as an additive for a hypoid differential? Liqui Moly says they produce MoS2 75w-90 on their site, so would mixing this in with a diff fluid change be safe?

After some more poking around I found that there's an LM MoS2 product specifically designed for gear oils. MOL-LM2019