I have used Mobil 1 for 87K miles and just switched to Pennzoil Platinum Full Synthetic today. According to the people on LS1 Tech and other sites it compares right up there to Amsoil. You can get it in a 5 qt. jug at wal-mart for just under 20 bucks. About 5 bucks cheaper than the Mobil 1.
Full Synthetic w/Superior* Active Cleansing Agents
Available Grades include:
0W-20, 5W-20, 5W-30, 5W-30 Euro, 5W-40 Euro, 5W-50, 10W-30, 10W-40, 15W-50
Cleans 3X better than the leading conventional oil.**
Who it’s for:
People who want the highest level of cleaning, protection and performance that the maker of America’s #1 passenger car motor oil provides -- our ultimate clean.
What it does:
Superior* Active Cleansing Agents go beyond cleansing the oil to continuously attack potential and existing deposits. In a severe sludging test, Pennzoil Platinum® removed almost half the dirt and deposits in a dirtied engine in just one oil change.
* Superior* Active Cleansing Agents help remove built-up
dirt and deposits 3X better than the leading conventional oil.**
* Unique Adaptive Molecules divide or cluster together under
extreme engine stresses of heat, shear and pressure to help
reduce oil breakdown and the resulting deposits.
* Our ultimate protection against performance-robbing deposits
that can dull engine response.
* Different grades designed to meet or exceed the toughest
automobile manufacturers’ specifications and approvals
including GM 4718M, Honda/Acura HTO-06, MB Approval 229.5,
MB Approval 229.51, VW 505.01, Porsche, and BMW LL-01.
(Specifications met vary by viscosity grade. Check product label.)
Meets or exceeds warranty requirements for gasoline and diesel engines
(specific viscosities for each). Consult owner’s manual to find right grade
for your vehicle.