Oil type viscosity / Regular or Synthetic ?

NH.Solar · 07-14-2021, 08:20 PM

Really good info from both Dick R and Likelakes. The second number in the designation is a bit more critical than the first as it is the base weight and viscosity when the oil is at running temperature. The first number is the cold viscosity and while it is best to be close it isn't as critical. Due to the cold viscosity additives the 15W will crank ever so slightly better than the 20W but it really affect your performance or longevity at all.
I used to run only Rotella in all of my engines out of habit because it was one of the last blends to have zinc additive but now use Walmart's Supertech brand full synthetic. Zinc is only really important when you have an engine with solid lifter cam and unless you have an old muscle car you needed be concerned about it. I do run full synthetic in everything, including my Duramax, Kubota, and vehicles simply because it cranks so much better when cold and isn't really that much more costly.
I have a mini-excavator that would crank but not start if it was below 30 ...until I changed both the engine and hydraulic oils to full synthetic. Now I can get it to start and move it out of the way even if it is only 20' out. pretty convincing. Second, I used to have a Vmax motorbike that had a common sump for both the engine and tranny and once I switched to full synthetic I found that it shifted much easier when the oil wasn't fully warmed up.

LikeLakes · 07-14-2021, 10:26 PM

Quote:

Originally Posted by NH.Solar

Zinc is only really important when you have an engine with solid cam rollers

You mean flat tappet engine, like a 351 Ford for example. Not meaning to nit-pick.

07-14-2021, 08:20 PM	#1
NH.Solar Senior Member Join Date: Jan 2017 Location: Jackson Pond, New Hampton Posts: 243 Thanks: 48 Thanked 142 Times in 79 Posts	Really good info from both Dick R and Likelakes. The second number in the designation is a bit more critical than the first as it is the base weight and viscosity when the oil is at running temperature. The first number is the cold viscosity and while it is best to be close it isn't as critical. Due to the cold viscosity additives the 15W will crank ever so slightly better than the 20W but it really affect your performance or longevity at all. I used to run only Rotella in all of my engines out of habit because it was one of the last blends to have zinc additive but now use Walmart's Supertech brand full synthetic. Zinc is only really important when you have an engine with solid lifter cam and unless you have an old muscle car you needed be concerned about it. I do run full synthetic in everything, including my Duramax, Kubota, and vehicles simply because it cranks so much better when cold and isn't really that much more costly. I have a mini-excavator that would crank but not start if it was below 30 ...until I changed both the engine and hydraulic oils to full synthetic. Now I can get it to start and move it out of the way even if it is only 20' out. pretty convincing. Second, I used to have a Vmax motorbike that had a common sump for both the engine and tranny and once I switched to full synthetic I found that it shifted much easier when the oil wasn't fully warmed up. __________________ Peter NH Solar Last edited by NH.Solar; 07-15-2021 at 06:03 AM.

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