Mobil 1 15w50 or 0W30?

[ToyotaNSaturn]

Welcome to the board!

With little statistical backing, I can only shoot from the hip on this engine, but I'd choose Mobil 1 0w-40 or the 5w-40 derivative "Truck & SUV" product. A bit thicker than the standard 30 weight products and provide excellent protection.

Even as a fan of Mobil 1 15w-50, I think it may be a bit too thick for your new truck.

 

[sasilverbullet]

So far, I understand the logic except for the "too thick for my engine".

How can it be too thick?

When I look at the specs on 15w-50, it seems to my untrained eye like the specs are better...please explain.

 

[ToyotaNSaturn]

Certain engines perform better with certain viscosity oils. For example, GM's 4.8/5.3L V8's enjoy a thick 30w or lighter 40w oil.

Check out the Used Oil Analysis section, namely this UOA:
http://theoildrop.server101.com/ubb/ultimatebb.php?ubb=get_topic;f=3;t=001810#000000

This is one engine where a 30 weight oil might be best. There's only a small amount of used oil analysis on this board for this engine, so it's difficult to tell for sure.

Why not try a good synthetic 30 weight (such as Mobil 1 10w30) and perform an oil analysis? The more data we have on this new engine, the better!

 

[sasilverbullet]

I've got about 3K on the 15w-50 that's in there. How about I do a analysis and post it and let you guys tell me what's up?

 

[ToyotaNSaturn]

Please do! I would like to see how that oil performs in this engine!!

 

[sasilverbullet]

I've never done an analysis on a car, can you recommend a company, and a link?

 

[ToyotaNSaturn]

http://www.blackstone-labs.com/

Fill out their online form and they'll send you kits for free. Please do get the TBN analysis option, too.

 

[sasilverbullet]

in a Nissan Titan in San Antonio, Tx. I pull a trailer and cargo quite a lot that brings it to it's max GVWR of 14,600 lbs. It's HOT down here about 9 months out of the year...

I bought it with 5k miles on it. I changed the oil immediately to Mobil 1 15W-50 and have put about 2.5K on it since. I also changed the rear dif oil to Mobil 1 also.

I'm new to this board, so please be gentle. I thought I knew oil until I started reading and searching on this forum.

Please "teach" me with your answers, and keep the techie lingo to a level that an old gear head can understand!

Thanks in Advance...

 

[dagmando]

If your want total protection under extreme conditions, use whatever grade your owners manual recommends but use a synthetic like Mobil 1. This is especially true in the rear diff but watch out for Posi-trac and the special additive required when replacing the fluid. I personally would not use 15w-50 unless your book has that rangem regardless of being Texas and towing.