B Low Oil Pressure...Still

Rotella has a HD 10w30 that is diesel rated I use it in my gas motors it seems to hold up well and has additives that I have been told help with the flat tappet on the old cams. Don't know for sure about the additives but it works well for me.

I HAVE 5-Bs, 3 C/A s- 1 C -2 WDs  for the last 30 Yrs THEY HAVE HAD 15/40  SUMMER & WINTER AND HALF THE TIME YOU CANT SEE THE GAUGE BECAUSE OF DIRT.

Allis dave wrote: Just last week, was down to 60 degrees maybe. Started up an old JD with SAE 30 in it. It usually runs toward the bottom of the medium pressure area. It was up in the high area for about 5 minutes until it warmed up, then back down to the M. There's a reason the old gauges had a "NORMAL" range. As long as you're in that range your "normal"

Agreed. Normal is normal.

DougS wrote: Hockeygoon wrote: A good 30 weight HD oil will have all the additives and detergents that 10W30 has.  And will not break down nearly as fast as 10W30 under heavy use.  Just put 10W30 in for fall and winter use. A modern automobile engine is much harder on motor oil than a D17. 10W-30 works just fine in an automobile engine. Todays multi-vis oils will outperform any engine oil of the 1960s. "Thicker is better" isn't true anymore.

At operating temp 10W30 is the same as 30 weight - nothing "thicker" about it. What is "thicker" is the oil at start up in cold weather - that is why I recommend switching to 10W30 in the fall and winter. If you are using a tractor for long periods of time under high heat conditions straight 30W is a much better oil than 10W30.


SAE30 weight is more shear stable than 10w-30. The SAE 30 does not have any viscosity index improvers, the 10w-30 does. Multi viscosity oils have polymers added to a light base (in this case 10W) that breaks down over time and use. In conventional oils the more polymers added the less stable the oil is under high heat - especially over extended periods of time.       


Above 40 degrees you gain little if anything using 10W30 over SAE30 weight while losing the stability of a straight weight oil.   

Something to consider about something that beats up oil is a 6.7 Powerstroke. 10-30 dino is recommended. Right now the 6.7 is the torque leader over GM and Cummins although the new Duramax is rated at 15 hp more. I see Ford coming out with a recall to flash them up to the Duramax.
Anyway both Ford and Cummins pulse the injectors in the exhaust stroke to dump fuel in the catalyst which results in fuel in the oil. Shear stability is definitely up to the task. The connecting rod bearings are not as wide as what's in the B125 engine. Only time I've ever see one puke is a programmer overfueling and over revving.
Oil technology has far surpassed even the 90s...