Originally Posted by posttosh
The list price appears to be $8.75/quart, which is probably what a local dealer would charge me if I bought it there. ... Rosenthal Arlington Mazda sells the Idemitsu Mazda oil for $6.83/quart, but the shipping costs would more than swamp the savings.
Oooh. The Mazda oil I saw must have been a different version of the 0w20. I saw it on the service desk at some dealer in Raleigh in the summer of 2011.
With cnc you can buy 6 quarts of Schaeffer (or 3 or 1), but the shipping is still $15. A case (12 quarts) through them works out to $93/shipped. Given the rate that my car is eating oil, I don't mind having a few extras around for a regular top off.
The Rosenthal Arlington Mazda delivered price for the Mazda GF-5 Idemitsu oil is $61.48 (=$41.58 + $19.90 shipping) for six bottles, or $10.08/quart, 23% more than the same quantity Schaeffer Supreme 7000 delivered from CNC-Motorsports, assuming the shipping charges are the same as when you last ordered it. But the Mazda oil is a full synthetic (base stock undisclosed) and is a 0W-20 (0W-xx are usually pricier than 5W-xx oils), whereas the Schaeffer is a 5W-20 semi-synthetic, albeit one that uses high quality Group IV (PAO) base stock. Running the price numbers alone, it almost makes it worth a trip to the snotty local Mazda dealer to see if I can get a deal on six bottles there.
Pennzoil Ultra 5W-20, another full synthetic reportedly made from advanced GTL -- gas to liquid -- base stocks, is very highly regarded on BITOG (and its Noack volatility number -- often commented upon on BITOG -- is jaw-dropping). Wal-Mart sells it -- but stocking is spotty. The Wal-Mart price for a 5-gallon jug is $28 (but out of stock on-line) or for a single quart $7.82 (also out of stock on-line).
It is a fool's errand to compare oils only on their specs, but here are some comparisons:
Viscosity, 40° C
Schaeffer 7000 5W-20 -- 43 - 45 cP
Mazda (Idemitsu) GF-5 0W-20 -- 35.852 cP
Pennzoil Ultra 5W-20 -- 47.43 cP
Viscosity, 100° C
Schaeffer -- 7.5 - 8.5
Mazda -- 8.37
Ultra -- 8.40
High Temperature/High Shear (HTHS 150° C)
Schaeffer -- 2.6
Mazda -- 2.6
Ultra -- 2.7
Schaeffer -- 12.8
Mazda -- not specified
Ultra -- 5.0
Total Base Number (TBN)
Schaeffer -- 7 - 7.5
Mazda -- 8.9
Ultra -- not specified
Viscosity Index (VI)
Schaeffer -- 158
Mazda -- 221
Ultra -- 154
The two numbers that jump right out at you are the Ultra's Noack volatility and the Mazda's VI.