First DIY Oil Change for '00 E430 with MityVac

[HTN-E430]

I bought the MityVac 7021 and oil filter wrench a couple months ago to change oil on the '00 E430 myself the first time, since I bought the car 5 year ago. All previous oil changes were done at dealer free of charge under the free scheduled maintenances.

I followed every step in the "Oil & Filter Change" of DIY, except the following:
After the MityVac made gurgling noises when it was done sucking up the oil, I removed the sucking tube from the MityVac to transfer 8 quarts of old oil into two 1-gallon milk jugs. Using hair dryer to blow hot air into oil fill for about 2 minutes, then re-connected the sucking tube to the MityVac which was emptied by then, and pumped about 10 times, another 1/4 to 1/3 cup of oil had been sucked into the Mityvac.

I also added 10 oz of Valvoline Synpower Oil Treatment, which has very high level of Molybdenum, to the new 8.5 quarts of Mobil 1 10W40. Before this oil change, my car gas mileage was between 18.3 MPG - 18.8 MPG with average speed of 28 MPH, to 18.5 MPG - 19.2 MPG with average speed of 29 MPH between filling gas weekly. For any week that the average speed went down to 27 MPH because of more red lights, the average fuel consumption went down to between 17.2 MPG to 17.8 MPG. Right after this oil change with Valvoline Synpower Oil Treament, the gas consumption improved to 19.8 MPG for the average speed of 27 MPH so far, an improve of about 10%. I saw similar gas mileage improved for my other car, Honda S2000 with Synpower Oil Treament. I will post more data about gas mileage for both cars when I collected more in the next few months. So far I am very satisfy with this Oil Treament for very little cost: $3.99 + Tax for 15 oz bottle at PepBoys and it can be used for 2 or more cars.