Oil question

Does anyone know if this oil from Walmart is any good?
I like the idea of 20w-50w rating for my 1075cc +10.5:1 compression ratio engine.
But I’ve never run a drop of synth oil in my KZ.
Been using Rotella for the last four years now.

I wouldn´t use synth oil in my KZ with a roller bearing crank.

Why?
Steve

Good question, Why? Synthetic oil is used in jet engines. I've never heard of synthetic oil being bad for roller bearings. I must admit I have only used dino in my Z1. However, I have been thinking of going to a synthetic since I use it in my C14.

Some people think synthetic oil is more slippery and causes roller bearings to skid and not roll. Personally, I don't think you need to worry about such things when using formulated motor oil. There are many many guys running synthetic oil in their GS Suzuki's over on the GS Resources site and I've yet to hear of one person having any issues.

I think this concern falls under “persistent urban legend.” I have not seen any real evidence that synthetics are more slippery. That is the role of friction modifiers that are so prevelant in automotive oils and are so damaging to wet clutches.
As I understand it, the advantage of synthetics is that they are crafted with short chain molecules that are better at resisting breakdown than long-chain molecules. This allows longer change intervals as the viscosity breakdown is much slower.

Unrelated to the friction issue, I heard an interview with a synthetic oil manufacturer and he seemed to confirm the idea that a motor that spent a long life of running non-synthetic should stick with non-synthetic, but the issue was oil seals. A seal broken-in to seal non-synthetic oil may seep a bit if it's suddenly having to seal out synthetic. I'm not sure if it was related to static seals like valve covers etc., but I think he was talking about crank seals, or whenever you have a moving part going through a seal.

Sorry I don't remember who it was... maybe Royal Purple or Amsoil.

Oil threads are great and I never reply to oil threads.... errr dang I think I just did.

:lol: :lol: :lol:

Synthetic oils maintain their viscosity through a higher and lower range of temperatures than petroleum based oils. Other than that, I haven't seen any real proof to other advantages. And no, it doesn't mean you can change the oil less often. It gets dirty just like the rest.

As far as break-in, everybody says don't use synthetic. Just to be safe I'll follow the lead and fire-up with petroleum. But several car manufacturers use synthetic from day one on performance engines.

VTEC wrote: Synthetic oils maintain their viscosity through a higher and lower range of temperatures than petroleum based oils. Other than that, I haven't seen any real proof to other advantages. And no, it doesn't mean you can change the oil less often. It gets dirty just like the rest.

As far as break-in, everybody says don't use synthetic. Just to be safe I'll follow the lead and fire-up with petroleum. But several car manufacturers use synthetic from day one on performance engines.

Synthetic oils hold their viscosity longer than dyno oils, commonly expressed as they "don't break down" as fast, which is true. That's why you can extend the change interval. The filter removes particulate matter and the oil contains acid buffers to offset combustion byproduct contamination. Diesel fleet owners perform oil analysis tests to measure things like how much acid buffer is left and the viscosity index to determine when the oil needs to be changed, and synthetic can definitely run longer.

Regarding synthetic oil from new, it's true that lots of engines come that way these days. On my KZ I still used dyno oil for the early break in miles though. The cylinder bores are not as straight and round as a brand new engine and I didn't want to push my luck. Call it lack of knowledge on my part maybe. Or superstition?