Re: Conflicting Advice. Who's right?

["Harold McElraft" <hmcelraft@xxxx>]

I suspect the reason there is so much suspicion and confusion about 
this topic is because most the information we get on the subject is 
from the folks that sell oil and, the manuals we have are making 
references and using information that is extremely outdated.  
Certainly, since the DeLorean was manufactured, considerable 
advancements have been made in lubricating technologies. I have 
personally fretted about this subject until I got some engineering 
information from a petroleum engineer friend some years ago and then 
did some reading on the subject.

There are many factors that go into recommendations for an engine 
lubricant. The engine tolerances, operating temperatures, emissions, 
oil capacity, circulating efficiencies in the engine just to name 
some. But the goals are proper flow, protection at high and low 
temps, and cleanliness.

Getting to the bottom line ? The DeLorean engine should use 40 
weight oil. Whatever W you want to use for winter or cold weather 
starting should be based on your local conditions. In Houston 10W-40 
works most of the time. In the Northeast (NJ) I use 5W-40 Synthetic. 
I would say for most locations and using conventional oil, stay with 
10W-40.

Actually there are probably 16 or so specifications one may want to 
review when deciding on an engine lubricant. However, you need not 
be that discerning if you stick to major brands like Shell, 
Valvoline, Pennzoil, Exxon, Havoline, etc. and yes, full synthetic 
lubricants are far superior to conventional oils.

My personal experience - when I lived in Houston I drove a DeLorean 
everyday for ten years and over 80,000 miles I used 10W-40 Exxon. My 
petroleum engineer friend worked for Exxon and he showed me that, in 
convential motor oils, the add-pack was everything and only the 
majors had the quality control to do it right. The oil and filter 
was changed every 3-6,000 miles depending on when I had the time, 
etc. However, today I use full synthetic 5w-40 and change the oil 
once a year. Last year I put about 7,000 miles on the oil.

The filter is probably as important as the lubricant. Don't use 
discount brand filters ? there is a real difference in quality here. 
The original Purflux, or Purolator, Bosch, Wix, or NAPA Gold is 
best. I personally do not like Fram. I use NAPA Gold 1085 (a cross 
with the Purolator L14670) because it is a large filter (I have the 
45 degree elbow on the oil sender) and I like the larger filter 
capacity.

Harold McElraft - 3354