Oil change on a 91 Miata

[lwrydr]

Suggestions on what brand of oil to go w/ on a 91 Miata? I just bought the car a couple weeks ago & want to give it some fresh oil even though the guy I bought it from said he just changed it.

I like to keep track of my maintenance records. He said he replaced all the other fluids too. By the looks of the car I believe him. Car has high mies 150K but runs like it has less. :drive1:

 

[mndsm]

Synthetic is good, I have Mobil 1 5w30 in the Mini and the Speed 3.

 

[dmention7]

I used mobil1 for a long time, but recently switched to penzoil platinum due to a bunch of rumblings about it holding up better in turbocharged engines. I would have no qualms about running mobil1 though--I think they make a high milage formula also

 

[darkdan]

Conventional oil + two treatments of www.auto-rx.com

Afterwards follow it up with a PAO synthetic like Mobil1/AMSOIL/Royal Purple/Red Line (yes, I'm aware RL is actually POE).

"High mileage" is basically "high marketing." They take a regular oil, add in a few extra seal conditioners, maybe some more detergents, and if you're really lucky some form of esters. Well, synthetics already have all those things.

However, I do always recommend Auto-RX to clean the engine (especially the ring packs) first. This will clean the seals and allow oil to flow to them again and condition them so you won't get leaks. Not to mention clean ring packs means better compression which means better gas mileage/hp.

Check out the compression numbers on this guy's test:

http://www.auto-rx.com/rms13

 

[darkdan]

Oh yeah, don't forget to pick a good filter:

http://home.mindspring.com/~cewhite3nc/index.html

 

[Big Nate]

I am not sure about any of those addatives. They seem a bit like snake oil to me. I would just go with a good high milage oil and that is that. If you plan to autocross or race the car then go with a synthetic and be ready to rebuild the motor.


By the way I sell that snake oil for $100 no retuns.

 

[lwrydr]

Thanks, someone mentioned Royal Purple & another mentioned RedLine. I have used Amesoil in my other PT & liked that. Yea I know I have high mileage on this car, but it runs really good considering.

I don't I beat on it too much, just a bit of spirited driving if you know what I mean... wink-wink ;o)

 

[darkdan]

I am not sure about any of those addatives. They seem a bit like snake oil to me. I would just go with a good high milage oil and that is that. If you plan to autocross or race the car then go with a synthetic and be ready to rebuild the motor.


By the way I sell that snake oil for $100 no retuns.

That's what I thought too many years ago.

Like I said, high mileage oil is nothing more than regular oil + more detergents and if you're lucky some form esters.

Auto-RX is made from 3 organic esters that actually do exactly what the bottle promises. Search google for stuff like "auto-rx reviews" and you'll see it's rare to find anyone that doesn't feel it's worth the money. Check out the forums over at www.bobistheoilguy.com and you'll see everyone loves Auto-RX. It's FAR from snake oil.


Now other stuff like Lucas, Z-Max, etc have been proven to not be beneficial and sometimes harmful. I'm an AMSOIL dealer and don't even recommend AMSOIL's cleaning product (it's basically just a bottle of kerosene).

As far as which oil.....like I said most of the top tier real synthetics are going to perform very closely that the average person couldn't tell a real difference. Here's what I mean by "real" synthetic:

http://www.caranddriver.com/feature...hetic_motor_oil_gets_all_new_semantics_column