Pennzoil has their newest oil out, Ultra, which 'looks' like it could easily do exteneded drains, and be competition for Mobil 1 Extended Performance and Castrol Edge in the '15k or one year' market.
But, Pennzoil is adament that they aren't marketing this as an exttended drain oil, they want you to follow the manufacturer OCI, or 4k miles. So Pennzoil doesn't technically have an 'exteneded drain oil' at all.
But this wasn't always the case. Way back, in the 1970's, Pennzoil marketed an oil called 'PZL', which was a semi-synthetic oil that was designed for extended drains. It came in 10W-40 and 10W-50, and was recommended for 15k or one year, whichever came first.
I'm wondering if Pennzoils aversion to blanket exteneded drain intervals come from experience with this oil - was this oil such a failure that Pennzoil said 'never again' to the extended drain market? All the 'sludge myths' about Pennzoil, did they come from this oil? Did people try 15k with it, and enough ended up with a sludgy mess that Pennzoil got a bad rep?
There were other '15k' conventional oils out at the same time - STP 10W-50, Gulf had a 'Multi-G' 15k oil, and QS 'Sterling' 15k oil. They all disappeared pretty quick, probably b/c of problems - does Pennzoil just have a long memory of what happened?
Johnny? You marketed Pennzoil around this time...what was happening?
But, Pennzoil is adament that they aren't marketing this as an exttended drain oil, they want you to follow the manufacturer OCI, or 4k miles. So Pennzoil doesn't technically have an 'exteneded drain oil' at all.
But this wasn't always the case. Way back, in the 1970's, Pennzoil marketed an oil called 'PZL', which was a semi-synthetic oil that was designed for extended drains. It came in 10W-40 and 10W-50, and was recommended for 15k or one year, whichever came first.
I'm wondering if Pennzoils aversion to blanket exteneded drain intervals come from experience with this oil - was this oil such a failure that Pennzoil said 'never again' to the extended drain market? All the 'sludge myths' about Pennzoil, did they come from this oil? Did people try 15k with it, and enough ended up with a sludgy mess that Pennzoil got a bad rep?
There were other '15k' conventional oils out at the same time - STP 10W-50, Gulf had a 'Multi-G' 15k oil, and QS 'Sterling' 15k oil. They all disappeared pretty quick, probably b/c of problems - does Pennzoil just have a long memory of what happened?
Johnny? You marketed Pennzoil around this time...what was happening?