Oil: what do you use?

[Ciotti]

Amsoil 5w-30, same price as the other synthetics but always beats them in the tests.

[DK Wolf]

Mobil 1 or Rotella all the way.

Don't fall for Royal Purple, it ruined my first 13B along with plenty of other engines on other forums.

[The Driver]

I went with Shell Rotella T-6 Synthetic 5W-40. Shell is well regarded in Miata circles due to the detergents. If you have lifter noise, this can definitely help resolve it.

Right here.

[I<3flippyheadlights]

I used to use whatever 5-30 synthetic blend was at my friends shop. I then soaked my engine in ATF and motorflush for a week. Changed that out and put in Rotella T6. Started up with llittle lifter tick, ran better and doesn't burn as much oil.



But it will show your oil leaks....

[The Driver]

But it will show your oil leaks....

Most if not all synthetic oils will do this. I mean, they are supposed be more slippery!

[I<3flippyheadlights]

I'm glad it did, just be prepared!

[Johnnie]

Mobil 1 Fully Synthetic 0W-30

Since maharaj is not running a 1.8, I'll chime in here, too.

Pennzoil Platinum 5W30 in the NC 2.0 MZR. Purolator filter is externally identical to the USA-made Mazda branded filter, but much cheaper.

[— kung fu jesus —]

I see lots of thick oils being used. Hoping there is an understanding about flow and pressure.

[Chops]

Not a 1.8, but I just put the middle one below in a couple weeks ago. Seems to be pretty good stuff so far.

[Pyr0monk3y]

Mobil 1 or Rotella all the way.

Don't fall for Royal Purple, it ruined my first 13B along with plenty of other engines on other forums.

I don't want to start an argument here but I've heard horror stories like that about every synthetic.

I think the real problem behind these oils is that they do such an amazing job of keeping the engine clean. If you run your oil for too long or if you have been running conventional oil for tens of thousands of miles, there is buildup inside your engine. The detergents inside synthetics like Royal Purple or Mobil one clean this build up. Unfortunately, sometimes this build up will be in the form of a chunk and clog an oil passage. Then.......... Boom

[RyanG]

I use rotella t6 because a few of the more hardcore people on Miataturbo have sent out various oils for analysis after use and t6 seemed to do the best in BP's.

[Andy]

I the Miata I use rotella t6. In my volvo I prefer to use Mobil one 0w40. It is one of the few true synthetics in America. It measures up to the European standard for oil testing which is much more rigorous and strict. It is a true synthetic rather than most other "synthetic" oils.

Even though it is a 40 weight hot it acts as a 35 weight.

By the way royal purple is not a bad oil if you are into brands but the problem with them is they have a relatively low shear time. After about 2000 miles the oil is pretty broken down and needs to be changed. Across the board Mobil 1 0w40 has been one of the best oils on the market.

I did way too much research on the matter one time. Rotella t6 is also another fantastic oil and has greatly reduced lifer tick in the Miata but is a little too heavy and too much detergents for me to want to run in a more modern engine. I have read some bad things about clogged cats.

[MiataMatt]

Honestly, I drive a 93 miata with 96k on it. It was made in 1992. 20 years ago we didnt have nearly as fancy synthetic oils as we do today, and the car was designed with clearances for conventional motor oil. After 96k miles of (i'm assuming, because it was an older woman who seemed to maintain the car, but not go above and beyond) generic jiffy lube type oil changes, I stick to my cheap oil. And I mean I walk into (insert autoparts store here) and buy whatever is on sale that week. This week it was 5 qts of quaker state conventional and a driveworks filter for $17.95.

The problem with switching to synthetic is the particles are not similar in size to conventional. Think of conventional particles like this : ooO0oo0oo0o0oOOO0o and synthetic like this: ooooooooooooo. The more uniformly smaller particles find their way out of any and all wear in any gaskets or o-rings etc. Also there is always the chance that the bearings and such are worn and the synthetic is too thin to lubricate properly. Under extreme forces (most often track driving) this can kill an engine.

All this being said, when I do build a motor for the miata I will break it in on full synthetic and run a high quality synthetic in it every oil change.

[Massiah]

I run Mobil 1 10/30 in the '99 with the Wix #51356 big filter. Engine is 2000miles old now. Thinking of going to Rotella T6 or Amsoil but no issues with Mobil.

The '94 I'm not sure yet. It just had an oil change done by the PO, he used Castrol HM 10/30 with factory filter. I'm going to move to the larger filter but idk what oil to use. What would you guys recommend for a 185k bottom end that burns a bit of oil (1qt every oil change, per PO)?

[Andy]

^ I would try to shell rotella t6. About $20 a jug on a bad day and the jug is 4 quarts ish. The miata only takes 3.5 quarts so you should have a little extra for the burning.