Modern Vespa

I tried to read up on this forum about the AGIP oil base to educate myself some more on how it's better than the Rotella T6 oil base, and I couldn't find much except some post where you mentioned that oils from Mobil, AGIP, etc are class 4 base while oil from Shell (Rotella) are class 3 base.

There's some indication that class 4 oils are fully synthetic while class 3 oils are not full synthetic. But then I read some poster in the regular MV forum mentioned that he called up Shell and asked directly and they claim it to be full synthetic and that some of their documentation was incorrect and they will fix it now that it's been brought to their attention

Anyway, if Rotella T6 claims to be fully synthetic and JASO MA compatible, are they perfectly good enough to use on the Piaggio? Why resort to something like AGIP that costs about 3 times more? Is the 3x ROI really worth the cost?

The other thing I notice is that there must be a dozen differrent oil brands at Walmart at all kinds of grades, yet I could not find any other brand on the Walmart shelves that would offer the 5W40 grade beside Rotella.

Why is the 5W40 grade so hard to find at a common store like Walmart?

"API Group III base oils are sometimes considered Fully synthetic, but they are still classified as highest-top-level mineral-base stocks."
https://en.wikipedia.org/wiki/Synthetic_oil

Shell called it's Type III hydrocracked mineral base stock oil a "synthetic oil". Mobil sued as Mobil 1 was Type IV and then considered a true synthetic. Shell won because they argued it was now different/better and thus synthetic...but also cheaper for them.

It comes down to what does synthetic mean. It was established Type IV and Type V are truly synthetic but Shell bent the rules.

It's only 1.5 quarts and maybe a few $s more on a high reving costly machine. The choice is yours where you cheap out. To me oil is the blood that keeps engines alive and I want the best in there.