Ok my curiosity is running wild. It seems as though the thicker oils are going the way of the dodo bird and that the thin oils are here to stay. But here is my question. Who still uses 20W50 oil? what do you use it in and why? and last but not least would you use it in a vehicle that is under 15 years of age, and under 200,000 miles?

I don't even use that syrup in my bikes!

Let me be more clear. I am looking for people who use it. not people who don't

I use 20W50 in my 1990 Toyota 4Runner. In the user manual there is a guide to see what oil weight should be used depending on the climate. Since I live in Hawaii, a 40 or 50 weight is used in this truck.

Similar from my truck's manual:

I`ve been using 20W50/15W50 in every car I`ve owned. Here`s a page out of the 1990-1996 Z32 FSM:

We run straight 50 wt in the Cessnas and Pipers I fly

I guess it's more ideal for aircraft because they're air cooled which is less consisent than water cooled engines.

Lots of people use it in air cooled motorcycles. I use Maxlife 20w-50 in my 1991 BMW R100. It is the grade that is recommended by BMW. Older BMW cars use it also. I have found that it is getting harder to find at superstores, but still readily at Auto part stores.

I use 15w40 and 20w50 in my ATV's because they run red hot and less shearing goes on...

I use it in my boats (which are GM V6 & V8 blocks)

I use M1 15W-50 (20W-50 is specified) in my 1988 Lotus Esprit Turbo.

Another reason for non-turbo applications to use it, is that Mobil has increased the ZDDP in it. This is good for the cams and followers. Not as good for the catalyst...

I understand that several other brands' formulations of heavier oil now still have ZDDP. Look for the SL spec.

I used it in my 1986 truck for over 10 years. Worked fine. Even used it with those "restrictive" Pure One filters and without a thermostat! Then again, I live in Florida and it doesn't get below 30 degrees but a few times a year.

Would I use it on my nice, new vehicles. Not so much. I think engineering is much better today.

I've used it for the first 125,000 miles of my truck's life. Now I've switched to synthetic.

Best use for 20w50 is to thicken your 10w30 in the summer at a ratio of about 1:4, which will bring the modern 10 cSt 30 weight up to an old fashioned 12 cSt 30 wt.

^^I noticed my jug of Mobil 1 15W50 silver cap has the SM,SL,and CF specs,but my jug of Pennzoil yellow bottle only has SM spec. What exactly does all that translate to when it comes to the ingredients/additives in both oils? Either one more robust/tougher than the other? The way my car performs with both oils,Pennzoil 20W50 yellow bottle wins hands down.

I run it in the GN and have for many years. Clearances are stockish except for piston to cylinder. It won't live on anything thinner.

To clarify, I use this year round and it works great. Believe it or not, the thick stuff eliminated the rod knock I experienced for the first second or two on startup on my older worn engine. It seemed to build pressure quicker on the thick stuff which goes against everything we read about on here.