Rotella T6 5W-40 synth all year around. Starts right away at -35C regularly without plugging in the block heater.

No need to flush. Just do a normal oil change.

 

+1 This excellent Shell oil flows well in sub-zero temps so you get better and quicker lubrication at start up. It's also easier for the battery / starter to turn an engine filled with 5W versus 15W. I'm also fairly sure T6 contains ZDDP since it's engineered for diesel engines.

 

Rotella T6! It is 5w40 which covers all of the temperature bases all year around.

 

Not to start an oil "war" but are you saying that T6 is not a full synthetic? I'm curious about your statement relative to RP.

 

And leaks out of holes in summer more easily?

There doesn't seem to be an outcry of emotion about running 15/40 in the winter so I think I might be safe.

Thanks all.

 

Here's another option: Shell Rotella T5 semi-synthetic


I've used the regular Rotella 15W40 and the T5 15W40...and the T5 comes in 5W30, too.


You might try the 5W30 in the cold weather. I'm not a fan of the T6 for my climate in the summer because I don't think it stays quite as thick when it gets up over 100 F. Just my opinion. And it's only about $1 per quart ($4 for the gallon) more than dino (regular) Rotella.

 

I wouldn't run 15w40 in the summer, much less the winter. There is no advantage to running 15w other than cost, and I hated the way my truck ran with Rotella T. I've run the 5w for a couple of years with no extra leakage.

The difference between Rotella synth and Mobil 1/ Amsoil/ Royal Purple is Rotella is dino oil that has been reengineered enough to be "synthetic" while the latter three are true synthetics that were designed from scratch to be engine oils.

 

If by "reengineering" you mean refining through a process called hydrostripping, then yes, it's "reengineered".


Hydrostripping is a rigorous cleaning process that removes the impurities found in crude oil (taken from the ground) to the point that it meets the specifications of the factory-synthesized lubricants. Some of the base products used by ExxonMobil or the companies that blend and package for Amsoil and Royal Purple (neither are a lubricant manufacturer) to synthesize the lubricants MAY have been derived from crude oil.

 

No, I was more talking about standard Rotella and T5, I have no experience with T6. Sorry for the confusion.

 

Just came upon this thread.

I would strongly recommend this site:Used Oil Analysis - Bob is the Oil Guy - Bob is the Oil Guy to anyone who wants the whole story on engine oil. It was an eye opener for me. Most engine wear occurs soon after startup. You want the lowest viscosity oil at that critical time. For that reason I use 0-30 all year round.