Clean from sludge or piston clean
- Thread starter AnarchyX
- Start date
- Status
Originally Posted By: CATERHAM
I did favour Pennzoil Platinum 5w30 over PU if you required a lighter 30wt oil, but that was partly because it had a VI of 177. But now that we know it is only 171 the lightness advantage over PU is lessened although the HTHSV difference is still significant at 3.0cP vs 3.2cP.
I would say basestock has a role to play as far as VI is concerned. PU is a different basestock, it probably doesn't need an as high VI.
I did favour Pennzoil Platinum 5w30 over PU if you required a lighter 30wt oil, but that was partly because it had a VI of 177. But now that we know it is only 171 the lightness advantage over PU is lessened although the HTHSV difference is still significant at 3.0cP vs 3.2cP.
I would say basestock has a role to play as far as VI is concerned. PU is a different basestock, it probably doesn't need an as high VI.
Originally Posted By: Falcon_LS
Originally Posted By: CATERHAM
I did favour Pennzoil Platinum 5w30 over PU if you required a lighter 30wt oil, but that was partly because it had a VI of 177. But now that we know it is only 171 the lightness advantage over PU is lessened although the HTHSV difference is still significant at 3.0cP vs 3.2cP.
I would say basestock has a role to play as far as VI is concerned. PU is a different basestock, it probably doesn't need an as high VI.
It's not a question of need as the higher the VI of an oil the better, all other attributes being equal.
PU uses heavier GTL base oil stocks than the lighter primarily GP III base oils that PP is formulated with.
Originally Posted By: CATERHAM
I did favour Pennzoil Platinum 5w30 over PU if you required a lighter 30wt oil, but that was partly because it had a VI of 177. But now that we know it is only 171 the lightness advantage over PU is lessened although the HTHSV difference is still significant at 3.0cP vs 3.2cP.
I would say basestock has a role to play as far as VI is concerned. PU is a different basestock, it probably doesn't need an as high VI.
It's not a question of need as the higher the VI of an oil the better, all other attributes being equal.
PU uses heavier GTL base oil stocks than the lighter primarily GP III base oils that PP is formulated with.
Originally Posted By: Falcon_LS
Originally Posted By: CATERHAM
I did favour Pennzoil Platinum 5w30 over PU if you required a lighter 30wt oil, but that was partly because it had a VI of 177. But now that we know it is only 171 the lightness advantage over PU is lessened although the HTHSV difference is still significant at 3.0cP vs 3.2cP.
I would say basestock has a role to play as far as VI is concerned. PU is a different basestock, it probably doesn't need an as high VI.
I think you're confusing the shorthand "VI" with "VII." VI is "viscosity index" and higher is always better because it means the oil doesn't change thickness as much with temperature. There are different ways to get high VI- you can start with a high VI base oil (best way), or you can add materials that to compensate for the thinning of the base stock with temp... those materials are "VIIs". VII is shorthand for viscosity index IMPROVERS- those long-polymers that help oil stay thick at elevated temps, but don't contribute to lubrication. I think that's what you're talking about- PU's GTL base stock doesn't need as much VII to get a high VI as, say, Pennzoil conventional does.
Originally Posted By: CATERHAM
I did favour Pennzoil Platinum 5w30 over PU if you required a lighter 30wt oil, but that was partly because it had a VI of 177. But now that we know it is only 171 the lightness advantage over PU is lessened although the HTHSV difference is still significant at 3.0cP vs 3.2cP.
I would say basestock has a role to play as far as VI is concerned. PU is a different basestock, it probably doesn't need an as high VI.
I think you're confusing the shorthand "VI" with "VII." VI is "viscosity index" and higher is always better because it means the oil doesn't change thickness as much with temperature. There are different ways to get high VI- you can start with a high VI base oil (best way), or you can add materials that to compensate for the thinning of the base stock with temp... those materials are "VIIs". VII is shorthand for viscosity index IMPROVERS- those long-polymers that help oil stay thick at elevated temps, but don't contribute to lubrication. I think that's what you're talking about- PU's GTL base stock doesn't need as much VII to get a high VI as, say, Pennzoil conventional does.
- Status
Similar threads
- Locked
- Locked
- Locked
