I used Liqui Moly MOS2 last year.First time.
Didn't keep track of gas mileage.

https://products.liqui-moly.us/mos2-...limo_b2b_us_us

Have used Molyslip E in the past and that increased gas mileage.
Last can of Molyslip E I bought several years ago looked like a dud in that you could actually see the gold color of the carrier motor oil so I don't think there was much moly in the can.
Never bought it again.