Modern Vespa

https://www.motortrend.com/how-to/diesel-oil-in-gasoline-engine/

Diesel oil is often used in larger motorcycle engines, whose owners have small budgets. It usually fulfills all the requirements in the JATO oil standard for motorcycle engines. That standard is mostly so the oil will fully lubricate the engine, while not making the wet clutch slip.
I have yet to hear of serious issue those owners have run into with use of diesel oil.

It is doubtful if using diesel oil in the small engines in scooters is worth it. Scooters rarely use much more than an a quart, or a liter, of oil so the price difference is negligible. They don't have wet clutches so you don't need the additives for that.

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Those that *do* have wet clutches (BV350 etc) don't share the same oil as the engine.
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Shell Rotella as an example is fine for scooters with dry clutches. Nothing to do with its price. It has all the lubrication properties necessary. MB specific scooter oil would be better?

Not sure about all motorbikes although it does comply with JASO MA.

I used T Rotella for 100,000 kms on 2 VStroms and it was fine, but I've not even considered it for the BV350. As you say the intervals are long and the volume small, so why not stay with the factory recommendations?
Shirker

Non detergent is important for any wet sump motor
The crank or straight cut gears splashing through oil with detergent will cause oil to foam

Does JASO say that?

AFAIK Shell Rotella only meets the JASO criteria for wet clutch applications such as a gearbox.

Specifically, it has friction modifiers to prevent clutch chatter.

Not all oils are the same, even if they have the same weight.

This is especially the case on modern day engines.

Example: Using a standard engine oil (even in the correct weight) will bugger up a modern diesel engine real quick because it is not a low spAsh oil to keep the oxidation catalyst and its associated regeneration devices functioning properly

So using the Shell example the Rotella would be harmful to a modern day diesel that has SCR (Selective Catalyst Regeneration).

For engines with SCR, Shell ECT in the correct weight would be the correct choice.

And in case you're thinking "but this does not apply to gasoline engines", it is already being put into a few of the latest cars and will come to motorcycles as well. Just you wait.

https://www.shell.com/motorist/oils-lubricants/helix-for-cars/helix-fully-synthetic/shell-helix-ultra-ect-c2-c3-0w-30.html

https://www.drive.com.au/news/what-is-a-petrol-particulate-filter-and-which-cars-have-them-in-australia/

I can't think of a reason not to use motor oil that meets the standards laid out by the manufacturer. Sure, they may get kickbacks for recommending a certain brand of oil, but you aren't bound to that brand. Just use decent oil with the specs listed by the maker.

I agree, but this oil does not, it meets diesel engine standards, diesels are low RPM engines, not high RPM.
Redline on my high RPM diesel powerstroke, was 3,600 RPM. And that is a high RPM diesel.

3600 rpm high ref diesel??? thats crusing for me at 130km is also topspeed with 80 horses at the cranck 60 at the wheel with Airco

My W903 209CDI sprinter does 4250 at trafficlights sprints redline is 5000

I'm not sure but i think my old C220 CDI did 4500 at 230km/h

A little 4 cylinder diesel and a V8 diesel (like Ford's PowerStroke) are worlds apart.

Example: In the truck world, the rev limit on a DAF 13Liter straight 6 cylinder is around 2000rpm, and peak power and torque is around 1500rpm.

The rev limit on Scania's 16Liter V8 diesel is even lower.

I have used diesel oil in high performing 4g63 motors. modified to nearly triple factory output. I was after the much higher zinc content.

I can say when the oil first goes in the engine becomes noticeably less tinny sounding. but that effect wouldnt last.

thanks to that article now I got to wonder if the zinc was indeed sacrificing itself like the article suggests.