Heavy weight oil, Rotella T, etc... Is it really beneficial?

[bmorecobra]

Yesterday I had a conversation with a good friend of mine who recently had his motor built (forged internals, etc..) and he informed me that the builder advised him to now run 15W-50 oil.

Now this is not the first time I have heard this. In fact it seems quite frequent that a lot of turbo cobra owners claim that they use Rotella T motor oil which is also a heavy/thick oil.

I pose this question to the oil gurus on here. Im not taking a poll as to who does and does not run 15W-50 oil but I'm very interested to hear some explanation for running/recommending such heavy/thick oil. The two reasons I have heard is these oils typically have a better formulation for engine protection, and that they cut down on engine noise (my engine is very, very noisy. the forged pistons make a ton of noise when they are warming up).



My car has a forged bottom end, teksid aluminum block, and a turbo kit on it. I am in the midst of adding an oil cooler to my car, so an oil change is in my very near future. I'd like to know if 15W-50 oil is something I should seriously consider.

Additionally Amsoil has a Dominator 15W-50 oil which means there is an outlet for a high quality 15W-50 oil out there if I do feel running such oil is necessary.

 

[Brutal Metal]

Too thick! 10W30 max

 

[50blackout]

Wouldn't this be a great (and only time) to use a break in oil like: http://www.amsoil.com/shop/by-product/motor-oil/gasoline/break-in-oil-(sae-30)/?code=BRKQT-EA

 

[UnleashedBeast]

My 2014 GT when NA used Amsoil Signature 5W-20 like a champ. The UOA @ almost 10K miles was superb. However, then I installed the Armageddon TT kit. Tried Dominator 10W-30, but had a "tap" in the bottom end under light throttle. It didn't tap under moderate or full throttle.

Upgraded to Amsoil Signature 5W-50, and the engine was silent again with the twins. It's all in the setup, and sometimes you will never know without trial and error. My theory, the oil feed lines to the turbos were taking enough fluid pressure at low throttle to start the engine. When you gave it more throttle, the pump had sufficient volume to compensate. A more viscous lubricant solved this problem.

 

[bmorecobra]

I can see that.

When my build was finished and I switched all the fluids over to Amsoil I was running the sig series 5W-30, but after a few months noticed the oil cooler leak (that I'm now fixing) so I eventually just started running M1 5W-30. Now that the leak is going to be fixed I want to go back, and just as in your case with the Armageddon TT build I am willing to try out one of these higher viscosity oils.

Additionally oil pressure and temp gauges are going in simultaneously so I'll have some sort of idea as to how the higher viscosity effects things other than engine noise/the seat of the pants gauge.

As of right now the new sig series 0W-40 is what I think I am going to go with. I'm living in AL for the next year or so, so its a warmer climate compared to MD, but I think if it works well down here I can just start running it all year round, even when I move back. 0W-40 seems like a nice zero compromise blend. Have you heard or had any feedback on the sig series 0W-40 in a Ford 4V?

 

[4a7191a]

I run the rotella T6 in all my vehicles.
I've heard nothing but good stuff on it.
it did seem to quite down the motors on the mach1 and lightning a tad.

 

[LS2GTO]

Too thick! 10W30 max

Without knowing the clearances in the engine (since the bottom end is aftermarket) how can you say what's too think or not?

In this situation I'd listen to what the engine builder recommends. Not only do they know the clearances of the engine (since it's not factory anymore) but if there's ever an issue with the engine they would be the first ones to talk to. You don't want to go against the recommendation of the person which is most likely offering you some sort of guarantee on the engine...

 

[ChrisGurrero]

Yesterday I had a conversation with a good friend of mine who recently had his motor built (forged internals, etc..) and he informed me that the builder advised him to now run 15W-50 oil.

Now this is not the first time I have heard this. In fact it seems quite frequent that a lot of turbo cobra owners claim that they use Rotella T motor oil which is also a heavy/thick oil.

I pose this question to the oil gurus on here. Im not taking a poll as to who does and does not run 15W-50 oil but I'm very interested to hear some explanation for running/recommending such heavy/thick oil. The two reasons I have heard is these oils typically have a better formulation for engine protection, and that they cut down on engine noise (my engine is very, very noisy. the forged pistons make a ton of noise when they are warming up).



My car has a forged bottom end, teksid aluminum block, and a turbo kit on it. I am in the midst of adding an oil cooler to my car, so an oil change is in my very near future. I'd like to know if 15W-50 oil is something I should seriously consider.

Additionally Amsoil has a Dominator 15W-50 oil which means there is an outlet for a high quality 15W-50 oil out there if I do feel running such oil is necessary.

Actually bmorecobra, Shell does not have a 15W-50 in its Rotella HDEO motor oil lineup. However, we do have a Shell Rotella T Triple Protection 15W- 40 motor oil, as well as a full synthetic Shell Rotella T6 5W-40 motor oil. Of course, both of these motor oils are formulated with an increased level of anti-wear agents (approx. 1200 ppm of zinc), which would be ideal for older flat tappet gasoline engines as well as older performance engines. - The Shell Rotella Team