I was reading a thread on here about how 10w40 used a lot of VI's and breaks down and leaves deposits. Is the same true for a synthetic 5w40 such as the Rotella T I just bought?
synthetic oil has a naturally occurring high vi, thus it does not need as much vii as dino oils, so a good quality synth 5w-40 will need very little vii, unlike a dino 10w-40, good example of this is rl 5w-40 vs pep boys brand dino 10w-40
quote: Originally posted by boxcomp: I was reading a thread on here about how 10w40 used a lot of VI's and breaks down and leaves deposits. Is the same true for a synthetic 5w40 such as the Rotella T I just bought?
A lower quality base oil combined with a wide spread results in an oil that will most likely sheardown a bit resulting in all sorts of "good" things...
Rotella 5w-40 is a group III 5w-40, and as such does have an amount of VII's in the mix, BUT it uses a very high quality base oil in conjuction with VII's that are very carefully selected (given it's an HDEO)
quote: Originally posted by Palut: From what I've learned here: Stay away from large viscosity spreads in dino oil
I would define more than 30 points as large for a dino, and more than 40 or 45 large for synthetic. But I really have no experience with large spread synthetics, so I could be very mistaken. If I am, please let me know!