So after reading through alot of the threads on oils it seems that Rotella T 15w40 is a great choic for the cooler months due to viscosity. I always ran it in my bikes (sport bikes) and loved it. After searching on Shell's site, I found out they make a 50W Rotella for diesels. I can get a 5 Gallon bucket of Rotella T 50W on amazon for 78 bucks, which works out to about 3.90 a quart and about 6 oil changes. My question is how do I know what the 50W oil is equal to viscosity wise? it just says 50w, not 20w50 etc. This may be a stupid question but hoping someone can shed some lite.

 

Around here you can go to walmart and buy it for almost the same price in quart bottles. I was just looking at some the other day to run in my old Yamaha.

 

I've always found 40w...never 50 though

 

The product you are looking at is an SAE 50. There is no such viscosity as a 50w. The product is a straight weight. It only meets a 100C specification.

It has no low temp pour rating.

Now this is all good if you live is a warm climate or only ride above say 45 degrees F.

It will work fine.

Ken

 

Im definitley above 40* here in North Carolina. I think Im going to give Valvoline VR1 a shot instead though. Reading the UOA's on that oil, its seems legit. Ill run 15w40 Rotella in the winter though.

 

I run Rotella in my primary, works out fine there....

 

Well went ahead and nixed that idea. Picked up some Lucas gear oil, valvoline synpower 20w50 and a quart of rotella t 15w40. Running the valvoline in the engine and rotella in primary. Of course Lucas was put in tranny lol. Cost me 40 bucks at local parts store plus the filter from HD dealership. I'm gonna run this 3k miles and send in a sample to Blackstone and see if I can go longer or not. I'm at 13,800 miles in my 2001 Fatty. Saying that so I can come back as I'll forget when it's time lol.

 

a straight 50 is quite heavy + your engine can be oil starved when starting! straight oils are outdated for sure unless your engine is really loose live very early harleys.

 

A straight 50 can be any number in the 40c rating, that's all. Means it wasn't rated @40c. Means NOTHING else. Could be too heavy or could be fine. That's the issue, that you don't know. Redline sells a straight 50 that pours like a 15 @ 40c, so the blanket statement that a straight 50 is too heavy in the winter is dead wrong.

 

If you are talking about the Redline 50WT, I believe it is a multi-grade (15W-50) rather than SAE 50.

I couldn't find a SAE 50 on their website.