15W-40 Oil For Hydraulic Roller SBC?

[COPO]

Why did you choose the 15W-40 Rotella? Have you compared it to other oil viscosities in the same engine?

I’ve used both synthetic and non in my engine from Pennzoil 5w30, Joe Gibbs 10w30, Brad Penn 10w30, straight 30w, Redline 10w40, GM 10w40, Valvoline 10w30, Valvoline 20w50, Amsoil 10w40 and so on. I picked Rotella 15w40 for it’s cleaning chemistry. Oops missed one, Kendall.

 

[Chevyforever]

I had a friend who ran Valvoline 15w40 in his 355, solid lifter engine for a number of years. When i had an opportunity to ask a Valvoline rep about it, he quickly replied don't use a diesel oil in a gas engine. There were a number of reasons why, which I can only remember a couple... it's not formulated for gas and it's not designed for higher rpm.

 

[biker]

I’m using 15w40 Rotella in my roller cam. Melling 55A oil pump. At operating temp it idles @23psi, and 60psi at 50mph. My builder said I can use up to 20w50.

I'm going to try the 15-40 as well. Roger built both our bottom ends, he used the same pump in mine too.

 

[Lowend]

It's already been mentioned that the engine builder / bearing clearances really determine oil weight.

That said, I'm not a big fan of high viscosity oils. The vast majority of engine wear occurs during startup when the system is priming. The lower the cold viscosity of the oil, the quicker it makes it around the engine during that startup period.
The older natural base, high viscosity oils (20W50, 30W) were really a band-aid for no-so-great chemistry and thermal breakdown. With good synthetic oils, the thermal breakdown temperature is so high, that's really not an issue anymore. IE - at the point in time you overheat one of those, something horrible has happened already.

Bear in mind also, Rotella is formulated for Diesels. Gasoline engines are very different internal environments, and diesel is not optimized for them.
IMHO, when in doubt, go with a 10W30 that is formulated for has engines.

 

[COPO]

Shell Rotella T4 15W-40 is a diesel engine oil, can be used in some gasoline engines, but it's not recommended for vehicles with catalytic converters. Diesel and gasoline engines have different lubrication needs. Diesel engines often require higher levels of certain additives, like zinc dialkyldithiophosphate (ZDDP), for wear protection.

Rotella T4 15W-40:
This specific formulation of Shell Rotella is designed for heavy-duty diesel engines and meets both API CJ-4 (diesel) and SM (gasoline) specifications.

Older Gasoline Engines:
Shell Rotella T4 15W-40 can be suitable for older gasoline engines, especially those without catalytic converters or with high mileage, as it provides good wear protection and can help maintain seal integrity.

 

[450bench]

A bunch of guys I know use 15w40 in every engine they own.
I use it a lot unless the motor has Morel hydraulic roller lifters. They like 5w30.

 

[Hogdaddy]

Here is the data sheet. Is this the same oil reccomended?

 

['70 Z/28 RS]

I might just try some in my car. Looks a bit dark and thick, but I heard it has good detergent properties in it!

 

[G72Zed]

Why did you choose the 15W-40 Rotella? Have you compared it to other oil viscosities in the same engine?

Everyone has their take on oil based on their findings and experiences, and "comparisons" can have a very broad range of outcomes based on the individuals findings, whatever the measuring stick may be, there's a big difference between assumptions and conclusions, as in "time & money".

The most important thing is using the correct oil for the application, the work is finding the best oil for the engine/application one has.

Got a Diesel engine, use oils developed for Diesels.

Got a high performance street/race engine burning pump or race fuel, use a quality oil with the correct add pack for the engine build and actual application, there's so many good choices out there, no need to play chemical engineer.

 

[76z28]

I use 15w-50 in my 6.0 set up--when I took the timing cover off when I did the larger lower pulley.. it was clean as a whistle and has always had great idle oil pressure and amazing hot oil pressure. You need a thicker oil when running the engine hard--so 15w40 would also work great.