939 Engine Oil

Are you on Bob is the Oil Guy?

kuksul08 said:

Are you on Bob is the Oil Guy?

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Like I said above, every few years I dig into the specifications and test results so as to be able to make an informed purchase decision.

The oil guy site is helpful too.

BIG changes coming to oil formulations by 2019. It will be interesting to see the updated test results.

A little off topic, but I was shocked to find the Shell Advance 4T on the shelf at AutoZone. I visited half a dozen Duc shops in the years since I purchased my bike and none of the carried it. I went with Amsoil because I trusted my original shops recommendation. Recently used the Shell because I couldn't find Amsoil as readily.

I was on another thread that warned against the Mobil 1. Narrative was it was developed for slower spooling cruiser twins. It was not accompanied by ASTM data. That bums me out, because I'm a devoted Mobil 1 fan for my cars.

gatdammit said:

A little off topic, but I was shocked to find the Shell Advance 4T on the shelf at AutoZone. I visited half a dozen Duc shops in the years since I purchased my bike and none of the carried it. I went with Amsoil because I trusted my original shops recommendation. Recently used the Shell because I couldn't find Amsoil as readily.

I was on another thread that warned against the Mobil 1. Narrative was it was developed for slower spooling cruiser twins. It was not accompanied by ASTM data. That bums me out, because I'm a devoted Mobil 1 fan for my cars.

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Yeah Mobil 1 20w-50 twin oil is not designed for these high revving engines, I wouldn't recommend using it either. On the other hand, RSL is a borderline petroleum engineer, so we should all take his recommendations and run ATV/UTV oil.

I'm going to continue with the Dirt Bike oil. Coming from off-road, I know the abuse enduro and MX bikes take. Good enough for them, perfect for me.

I understand the trade-off being more frequent oil changes. Not that I would ever ride a bike 9,000 miles with the same oil.

It seems strange that people discussing oil offer conclusions without information to demonstrate their assertion. Seems emotional rather than informed. My analysis of the attached test results, oil manufacturer specifications and Owners Manual pages may be all wrong. That said, my conclusions are based of an analysis of the attached information, over a lot of years of looking at similar data, and without emotion.

Blending two 10w-40 Mobil 1 4T with one 20w-50 would yield 16.3 viscosity. Allows one to get into the zone for viscosity and use Mobil 1.

The slow reving matter relates to viscosity. Solved by the blend.

gatdammit said:

A little off topic, but I was shocked to find the Shell Advance 4T on the shelf at AutoZone. I visited half a dozen Duc shops in the years since I purchased my bike and none of the carried it. I went with Amsoil because I trusted my original shops recommendation. Recently used the Shell because I couldn't find Amsoil as readily.

I was on another thread that warned against the Mobil 1. Narrative was it was developed for slower spooling cruiser twins. It was not accompanied by ASTM data. That bums me out, because I'm a devoted Mobil 1 fan for my cars.

Click to expand...

My guess - an air cooled slow revving twin, beats the hell out of oil more than a fast revving watercooled twin. Some of those Cruisers have to go into "parade "mode because of heat dissipation issues. I think one cylinder deactivates, and American flags emerge from the mirror stalks.

I think cruisers need thick oil because of the 1930s tech.


What will be interesting is how the specifications change with the V 4 engines. Maybe a VW influence? Maybe 0w-20 oil? Euro 5 engine? European cars are at Euro 6 now, aren't they? 4 way catalytic converters and all.

Thinking more about it, Germans have determined that the 500cc combustion area is the perfect size. So, the new Ducati V4 would have to be a 2 liter bike to meet that determination. So, the design must be Ducati alone.