Oil Question - weight (not synth or snake, just oil)
 

So I come to find out that the previous owner ran 20w-50 oil in the ol 300E. I'm in a colder drier climate and run and different weight oil in the car. What would some of you guys recommend? I flushed the engine and ran a part syth oil. The car indeed leaks a bit of oil (no biggy). Thanks.

Lately I am reading a lot about oils, about their base stock, additive, the whole nine yards. I compared all the numbers and am getting convinced that the universal oil in 15W-40 grade is the way to go, for diesel or gas engine.

Among the popular ones, there are the Shell Rotella, Mobile's Delvac 1300, and Chevron's Delo 400.

Among the three. Rotella is the inferior one (although the most popular). It uses a Group I base stock so it has a higher pour point, lower flash point, and a higher Cold Cranking Viscosity (CCV).

Delvac 1300 and Delo 400 used to be on par. Both used Group II base stock and many numbers are comparable. However, since Mobile switched formulation by using a mixture of Group I and Group II base stocks, Delvac's pour point is higher, flash point is lower, and worst of all, its CCV has increased dramatically. Delo 400's CCV is 3150 cP @ -15 deg C and Delvac's is at 6000 cP @ -20 deg C (it used to be 4000 cP @ -20 deg C). Although the number for Delvac is 5 deg lower but the change from 4000 to 6000 is quite large due to a base stock change.

There are still lots of the old Delvac left in stores but I will not be buying the new formulation.

Chevron Delo 400 is what I will use in my diesel and gas cars, except in the Michigan winter. Delo 400 15W-40 has a pour point of -39 deg F. The Group II base stock really shows how fluid it is at cold. In the winter I will mix 50/50 with Chevron's 5W-40 synthetic, also a universla grade oil, for both gas and diesel engines.

I believe in the benefits of 15w-40, its been used since new in my '94 e500 (Penzoil Long Life brand), >>>oil/ filter changes every 1500 miles<<<

-fad

thanks
 

thanks for the info. I appreciate it.

fad:

The Pennzoil 15W-40 is also an excellent oil. I would rank it better than the new Delvac. Pennzoil uses a very pure basestock (Group II) with a low pour point. Its CCV is a bit higher than Delo 400 15W-40. If I remember right it is 3500 cP at -15 deg C (vs 3150 cP for the Delo 400).

Thanks for the info BO-

-fad

i just started using Castrol 15w-40 any comments on that one? haven't seen the Penzoil anywhere...

Joe:

I cannot find its specs on the Castrol Website.

From the old information at

http://pacific.telebyte.com/allanw/binder/info/oilfaq.html

It seems its pour point is very high (-15 deg). On that page, Delo 400's pour point was -27 but it is now at -39.

has anyone used 15W40 Quaker State Universal Grade?
any technical info? just curious.

joel:

I am compiling as I type.

The Quaker State HDX Plus 15W-40 has

pour point of -32, a falsh point of 210, and CCV of 3500 @ -15°C.

Delo's numbers are

pour point of -39, a falsh point of 230, and CCV of 3150 @ -15°C.

Ergo?
 

pretty hard for me to crunch those numbers.
so, is it good, better, or bad? will you pour it
into your sump? TIA

Just between these two oils (QS HDX and Delo 400), the Delo is superior because

Delo has a lower pour point (so it is more fluid at low temperatures)

Delo has a higher flash point (so it is more stabile at high temperatures)

Delo has a lower Cold Cranking Viscosity (so it is easier to pump at low temperatures)

i was a quaker state man myself, until i met a diesel mechanic who told me that you cant beat delo 15-40 for a diesel. i have 301100 mi on my engine so i was considering a 20-50. any ideas on that. i live in CA so weather is not a big factor. any comments.

I would stick with your success, i.e., Delo 400 15W-40.

AFAIK, there is no popular 20W-50 oil that carries the CH-4 rating.