Stale post. I'm late to this party, but wow, you guys are harsh.
Full Disclosure - I went out of my way to buy German Castrol for my C5.... back when it was still green
I like to experiment. I've messed around with Slick 50 (caused seals to leak but increased my fuel mileage without other problems), Auto Rx (no substantial changes noticed when used) and Lube Control (never bothered with UOA to see how well it works).
I met Dan; I know Dan. He sells the oil by the quart and gallon if you're interested. The bottles, as you noticed, are food oil bottles he got in bulk so he could sell it to shade tree mechanics such as myself. He makes his money doing mobile oil changes.
I put it in my wife's Sooby. Mileage initially increased from 23.5 to 26 mpg for about 4000 miles and then settled down to 25 mpg, mixed city and highway driving including multiple trips into the mountains fully loaded with two 60 lb dogs. So, initial mileage increase was 2.5 mpg, or over 10% increase. Was previously running a semi-synthetic prior to the oil change.
Just sent the sample in two days ago for the UOA on @ 13,000 miles with filter changes and top-offs @ 5000 miles and 10000 miles. I didn't stretch it to 15000 mi before the oil change because I hate pushing it that far without data.... and I was going against Dan's advice (he advocates the two-step (two-change) process).
Along with the increase in fuel mileage I saw a substantial decrease in oil consumption.
I'll hold judgment until I get the UOA back.
I'll share the UOA if anybody is interested and doesn't flame me and my numbers.
Cheers!
- TopCat