Engine and transmission oil poll

The place to discuss problems and routine maintenance questions and tips that are NOT specifically diesel-related.
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Posts: 27
Joined: Sun Mar 21, 2021 11:51 pm
Location: Oregon
Isuzu vehicle(s): 1984 diesel longbed 4wd P'up

Engine and transmission oil poll

Post by moroza »

In researching oil suitability, there's rigorous study of the chemistry and physics on one hand, and isolated anecdotes on the other. The former is often daunting, and the latter near-useless without context. I want to compile in one thread people's experiences with different (diesel) engine and (manual) transmission oils, along with their frame of reference - that is, other oils used. These will be anecdotes with context, and hopefully useful data for those who care about their Pup's oil, but can't afford to do hardcore scientific analysis.

So if you've used different oils in your Pup's diesel engine and manual trans, and noticed any differences, please copy and fill out this template, and reply here.

Oil brand and model:
Nominal viscosity:
Years used:
Miles on engine:
Change interval:
Oil consumption:
Cold performance:
Warm performance:
Other comments:

I'd start, but I just started using my Pup so I haven't experienced different oils. Instead, I'll do an example based on my BMW 544iT:

Oil brand and model: Castrol Edge
Nominal viscosity: 5W30
Type: full-synthetic
Years used: 2011ish, again in 2015-16
Miles on engine: ~170k first time, ~200k second time
Change interval: about 11k both times
Oil consumption: negligible
Cold performance: unremarkable
Warm performance: unremarkable
Other comments: turned a light-medium brown by 11k, and both times had lifter issues after sitting for some weeks.

Oil brand and model: Amsoil Euro
Nominal viscosity: 5W30
Type: full-synthetic
Years used: 2012-14, 2016-17
Miles on engine: varied 180k-210k
Change interval: 11-14k
Oil consumption: negligible
Cold performance: unremarkable... which is remarkable at -16C one winter
Warm performance: engine somehow sounds and feels a bit smoother than usual
Other comments: was still quite light by 14k. Never heard lifter tick. Subjectively, the best oil I've used.

Oil brand and model: Mobil 1
Nominal viscosity: 0W40
Type: full-synthetic
Years used: 2010, 2018
Miles on engine: 156k, then ~220k
Change interval: 10k+
Oil consumption: about 1 quart (out of 8) after 10k miles
Cold performance: not really tested
Warm performance: feels a touch smoother than the Castrol, not as good as the Amsoil
Other comments: gaskets were a bit weepy after switching to it. Seems a good oil otherwise.


Oil brand and model: Royal Purple Synchromax
Nominal viscosity: ??
Type: full-synthetic
Years used: 2010-2018
Miles on engine: 156k-210k
Change interval: three-ish years
Oil consumption: none
Cold performance: really stiff shifting required double-clutching. Bearings seemed ok.
Warm performance: mediocre shifting, but zero bearing noise.
Other comments:

Oil brand and model: Redline MTL
Nominal viscosity: 75W80
Type: full-synthetic
Years used: 2018-22
Miles on engine: 210k-230k
Change interval: haven't changed yet
Oil consumption: none
Cold performance: good, a bit stiff.
Warm performance: excellent. Still no bearing noise, and a lot slicker synchros than with the Purple.
Other comments:
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