Motor Oil for a Miata!

[POS Racing]

Back on the post about how Altiain needed to get his motor rebuilt there was some talk about oil! Couple of posts intrigued me so I'm starting a new post!

Now who wants to go first on the correct definition of "W" grades?

I don't know the correct definition, can you enlighten me??

[jolberry]

I googled this up.

[POS Racing]

I googled this up.

Well gee I could have done that! I was wanting to see what some of our engineering types had to say!
(It make them feel wanted )

I have always used 10W30 Mobil One in the NB's.

[Dave04]

I have always used 10W30 Mobil One in the NB's.

That's what I'm running in the Stook.... The owners manual makes a point that the car is shipped with 10W30 and is the recommended oil for the car.

[Darron65]

Okay, I powerscanned that link but didn't see any details about viscosity grades. The W (for winter, duh) grades are run at various temperatures and the oil tested must be below a certain viscosity. This is completely different from the high temp tests that are all run at the same temp with various results.

So anyway the way I remember it is the 15W test is run at -15°C. The 10W test runs at -20°C, 5W runs at -25°C, and 0W is tested at -30°C. You can probably guess that the 20W test is at -10°C. An oil passes if it does not exceed a certain viscosity at that test temperature. The max viscosity is the same for all grades except 0W which has a slightly lower limit. You can safely use the test temperature +10 as your own personal "minimum start-up temperature". Which means 10W anything is A-ok for Texas, although 5W may allow slightly easier starts.

One of the hats I wore at my old job was that of "oil nazi". I had to make sure every piece of mobile equipment (~1000) survived every start-up.

[Treibenschnell]

10W30 in all the cars... synth in the Miata and the Sled, dino in the Honda.

[Darron65]

Hmm, looks like some things have changed a bit since I was in the know. Here is a concise summary.

[Dave04]

10W30 in all the cars... synth in the Miata and the Sled, dino in the Honda.

Just to be curious... why are you keeping the Honda on dino?

[Treibenschnell]

Just to be curious... why are you keeping the Honda on dino?

Cost...

Currently, it's the most used vehicle we have.