The reason for the Rotella is the detergents and zinc. regular 10w40 may or may not be best for your old skool flat tappet pushrod Buick motor.

The Rotella 15w40 might just be what your previously used engine needs for a good cleaning. I know my 2003 loves the stuff.

My Rover mechanic uses the Lubro Molly 15w40 in all the trucks he works on, and the major LR indy shop in Seattle uses 20w40 diesel engine oil exclusively on all his customers rigs, and they have a stellar reputation. (lamorna garage)

I've been using the Rotella 15w40 since I've been doing most of my oil changes myself this year. And that is based on many many posts on this site.

No cold start problems with the few weeks of freeze we have in the Pacific Northwest.

 

Conventional will not hurt anything and for the most part is recommended. Roll with Rotella Shell 15w-40 or Mobil 1 Delvac 15w40 with a mobil 1 301 oil filter. In my opinion, do not flush the engine.

 

That's good to know. That's what I have in mine - Rotella T 15W40 - since the last oil/filter change about a month ago. But I was thinking of swapping it for conventional before the Winter hits. Good to know it should be good. In North Jersey/NYC, we don't have harsh winters like say Minnesota or anything.

-Anthony

 

Here is a motor oil flow chart for you guys.
It gets cold here in the winter so I use the Rotella 5w-40 then switch to the Rotella 15w-40 for the summer doing 5,000 mile oil changes and I use NAPA middle line oil filters 90% of the time.
Dont do a engine flush, the Rotella will slowly clean your engine as you drive.
Wal-Mart sells Rotella for cheap.

 

Here in Dallas the 15w40 Heavy Duty oil is perfect. I went with regular 10w40 my first oil change but the second go around I switched to Rotella. Engine honestly runs smoother.

I understand the desire to do things "by the book" but in this case a slightly heavier oil is exactly what your engine wants and needs. The thicker oil will stay in the worn bits of the engine better than the regular 10w40. Shell Rotella, Chevron Delo or Mobil Delvac are the brands you want. Get what is cheapest at the time / whoever you hold stock in.

Also, I use the "Mann-Filter W 950/4 Spin-on Oil Filter" off Amazon. There is a thread on here about it if you're interested. The gist though is it's a very high quality jumbo filter that provides some extra oil capacity.

 

Just changed my oil this afternoon for the first time... Put in the Rotella 15w40 and my rover really does run smoother now. I won't put anything else in now. The filter I got was just a standard Mobil 1 m1-204. They were out of the 301 or I would have put that one in.

 

Thanks a ton, guys.

 

If it is not getting below freezing there, I would not use synthetic.

When I have used Synthetic - the oil is BLACK after 2,000 miles.
Either the Synthetic is cleaning my engine and the soot and dirt are suspended in the oil

Or -
the Synthetic is actually causing MORE wear as it is too thin.

I like Rotella 10-40w standard non-synthetic oil.
The Rotella will stay fairly brown after 1,500 miles
on a 164,000 mile engine on our D1.

D1 and D2 engine - pretty much the same in the crankcase where the oil protects.

I also put Rotella in the D2.

I did use Synthetic in the D1 when I first bought it in 1997.
Figured after many years that non-synthetic for the D1 was better.
Seemed by the color test to last longer.

All the Amsoil dealers will freak out on me and tell me I need oil analysis to completely understand the wear factors..
I just go by color of the oil.

 

I run Amsoil in all my vehicles and have been running 10-40 with heavy zinc content that Amsoil offers in my D2. Now, since headgasket job last year, it leaks really bad at the rear of the valley pan gasket. I have just recently started adding the Rotella 15-40 conventional oil for about 2 qts total now of topping off from the leak, and the leak has slowed significantly. I will be changing out the Amsoil in my D2 for the Rotella 15-40 conventional on my next oil change and see how that works out.

 

The color of the oil means absolutely nothing.
You need a oil analyses to know for sure.
When I get the oil changed in my Duramax, it is pitch black after the first start of the engine.