crude oil has wax in it.The only thing I remember from back then (high school mid 70's) was not to use Pennzoil because it had wax in it.
crude oil has wax in it.The only thing I remember from back then (high school mid 70's) was not to use Pennzoil because it had wax in it.
Maybe in the US, not in Europe, until not very long ago it was certainly still the best seller.10W-40 fell out of favor after all the news about it.
The cars were actually getting a lot better, particularly from the mid-80's on. Ford introduced their SEFI system, EEC-IV, GM introduced TPI, and power output started going back up considerably over the smog engines from the 70's.The cars sucked... the oil was fine.
Very common back then.He replaced it with a 350 gas engine...
The problem came from two extremely cold Winters in a row (two years) in the upper Midwest regions of the US. These cold snaps lasted for months not just days or weeks. General Motors was hit with a huge amount of warranty engine replacements and studied the problem. They discovered the problem was with 10w-40 oils.Maybe in the US, not in Europe, until not very long ago it was certainly still the best seller.
The oils in the 1980s were perfectly fine. It was mostly owner neglect that got all those oil urban legends started.
The problem came from two extremely cold Winters in a row (two years) in the upper Midwest regions of the US. These cold snaps lasted for months not just days or weeks. General Motors was hit with a huge amount of warranty engine replacements and studied the problem. They discovered the problem was with 10w-40 oils.
I don't think Europe, in general, experiences these temperatures for extended lengths of time.
What ka9mnx is referring to is an issue with engine failures due to inadequate knowledge of how oil performs at low temperatures. This also happened in the mid-1980s and led to a revision in SAE J300 regarding the metrics used for determining an oil’s winter rating.
It wasn't related to an automobile manufacturer, it was related to the oil. Our conversation is drifting a bit here about "How bad were oils in the 1980’s" since we are talking about two different subjects. I do know about the viscosity modifier problem.I can find no documentation that GM experienced a large number of warranty replacements due to 10W-40 being used in cold temperatures.
In fact, all I find is that GM's issue with 10W-40 is as described above, they believed it could cause piston ring sticking due to the use of excessive VIs.
Worth noting that the oil viscosity chart I posted above, while not allowing the use of 10W-40, does allow the use of 15W-40 which would be expected to have even worse low temperature properties compared to 10W-40.
It wasn't related to an automobile manufacturer, it was related to the oil. Our conversation is drifting a bit here about "How bad were oils in the 1980’s" since we are talking about two different subjects. I do know about the viscosity modifier problem.
Here is some discussion on the cold-weather performance issue:
Automotive - Lubes'N'Greases
Steve Swedberg clarifies the ambiguity of SAE engine oil viscosity classifications.www.lubesngreases.com
Back in the day CCS and MRV weren't used for cold temp performance, it was based on pour point, which proved to be wildly inaccurate in certainly situations. One of those situations was encountered during that winter that somebody recounted where, despite the oil being above its pour point, it failed to pump. I believe this was a Quaker State product IIRC. This resulted in a huge pile of failed engines.Maybe I misunderstood, but the impression I got, reading what is stated above, is that GM's issue with 10W-40 is due to inappropriate use in cold weather.
Back in the day CCS and MRV weren't used for cold temp performance, it was based on pour point, which proved to be wildly inaccurate in certainly situations. One of those situations was encountered during that winter that somebody recounted where, despite the oil being above its pour point, it failed to pump. I believe this was a Quaker State product IIRC. This resulted in a huge pile of failed engines.
IIRC, it may have been related to VII content, and the 10W-40 had a lot more VII in it.What is the connection between this event and 10W-40 oil? Was that the only weight of oil affected by the problem?
I used to buy superflo 20w-50 by the case just for the cool tiger on the bottles. And havoline sae30 because it was $.49 a qt.1980s era:
Pennzoil and QS. I buy them by the box for the rebate.
Havoline & Superflo if there's a sale as well.
The oil grades were in par with the current car models during those times.
You may be correct but I thought it was a problem with deposits and ring sticking due to high levels of poor(er) quality viscosity modifiers. The conventional base stocks of the time had a low viscosity index.Maybe I misunderstood, but the impression I got, reading what is stated above, is that GM's issue with 10W-40 is due to inappropriate use in cold weather.
Yep. Back in the day my neighbor said it was because Pennzoil was or was not a paraffin-base. I can't remember which.The only thing I remember from back then (high school mid 70's) was not to use Pennzoil because it had wax in it.