Originally Posted By: Gokhan
(1) First of all Toyota Genuine Motor Oil (TGMO) is made by ExxonMobil.
(2) Second, Toyota makes sure that TGMO has the best possible additive package for Toyota engines, including a generous amount of antiwear additives ZDDP (P) and moly (Mo), and no large amounts of magnesium (Mg), which is potentially corrosive and increases wear.
(3) From the viscosity index, TGMO seems to have more Group IV (PAO) in it than Mobil 1, therefore possibly a "more synthetic" oil than Mobil 1 (TGMO having less Group III dino in the mix). This means lower NOACK, which implies less deposits, more high-temperature stability, and less oil consumption. Although, I should say that this last point is something that is inferred and there is no direct information on this.
One can also argue that the large amount of Mg in Mobil 1 can help extended drains by providing TBN retention, which is what the Mg is for. But then Mg is also potentially corrosive and increases wear. Therefore, Mg in Mobil 1 has mixed benefits and potential harms.
After what I discussed above, TGMO 0W-20 is a better oil than Mobil 1 0W-20 in my opinion. This is especially so if you own a Toyota. TGMO is also cheaper than Mobil 1, which is another benefit.
These are the current prices of TGMO 0W-20 at Toyota dealers:
00279-0WQTE-01 $5.32 - $7.25 per quart
00289-1QT0W-T1 $4.89 - $6.66 per quart, need to buy 12 (case)
The cost to dealers is slightly (about 18%) less than the first number. The second number is the Toyota suggested retail price. Therefore, if you get the TGMO 0W-20 for around $5 - 6, you have a great deal, knowing that you bought possibly the best oil out there at a great bargain.
There are a lot of inaccuracies here. Toyota 0w20 is a very good oil, and probably the most fuel efficient. However, it only meets API SN where the M1 meets ACEA-08, GM 4718M. Volatility and base oils used will exceed the Toyota oil. XOM will use their best stuff in M1, not TGMO.
Where are you getting this idea that TGMO is using more PAO? Have you seen the MRV #'s for M1? In extreme temperatures, the Toyota is not as good. In terms of deposits, M1 is at the top.