Hello all-new here.
I have used both the Mobil HM Blend and the Quaker State HM. I like them both.
When I first put the Mobil HM 10w30 blend in my son's Beretta (3.1 V-6), it started leaking out of the corners of the front valve cover gasket, developing wet "sludge trails" that dripped down to the exhaust manifold. It is on its 3rd OCI, and at some point it quit leaking and the trails have dried up. I do think there is something to the "seal conditioning". I did not see any change in consumption, but it is only about 1/2 quart in 3000 miles. I use both the Mobil NV 5w30 and HM 10w30 blends in our two Ford trucks that see a lot of short trips because I like the higher detergents.
I drive an old 87 GMC with a 305 V-8 200,000+ miles. After I did a valve job last fall, it started consuming a quart of conventional 10w30 per 1000 miles. I just finished by first OCI on Quaker State High Mileage 10w40. Consumption decreased to just under 1 quart in 3000 miles. It has never leaked much, but leakage has decreased to a very small drip (stain) on the garage floor. Since I replaced all the gaskets in the top end, along with the oil sender, I dont know how much the decrease (if any) is due to the oil.