[TR] OD Oil

Randall TR3driver at ca.rr.com
Wed Jun 20 09:21:01 MDT 2018


MT-90 is actually a 75W90 formulation, which is roughly the equivalent (in
viscosity) of 15W40 motor oil.

This means that, at cold temperatures, MT-90 is actually thinner than ND 30!

There is a neat on-line calculator at
http://www.widman.biz/English/Calculators/Graph.html
Where you can plug in the viscosity at 40C and 100C from the product data
sheet and graph the results at lower temperatures.

Plugging in the numbers from the MT-90 datasheet and Valvoline ND 30
produced the attached chart.  

As you can (hopefully) see, the two curves cross at roughly 30C (86F).  Even
at room temperature, the MT-90 is actually thinner than ND 30!

Of course, it almost never freezes where I live (near Los Angeles, CA), but
I can vouch that MT-90 does shift easily on cold mornings, even when the
overnight low was close to freezing.

-- Randall

> The only downside I can see is that winter driving may 
> require some time for the TR3's gearbox to warm up or 
> shifting gears may take a little extra effort before the 
> gearbox and it's oil warm up a little. 
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