What oil do I need?

[Brandon1048]

I didn't want to start one of these threads immediately, I was sure everyone would be sick of them. Since I saw a thread suggesting the best way, I thought that I'd see what the experts here think.

My car is a 2004 Mazda Miata MX-5 MAZDASPEED. The engine is a 1.8l 16-valve 4-cyl turbocharged and intercooled. It has no known problems, but I've only put 1500 miles on it and it just hit 50,000. It may not be relevant, but this car does 2500rpm@50mph and 3500mph@70mph in 6th gear. My car warms up with incredible rapidity. The heater blows hot in less than a mile. Probably because the radiator is after the intercooler and a/c condenser in the fresh air stream.

I drive it pretty lightly compared to most who have this model, although I do 720 mile round trip interstate trips every few months and fully utilize the turbocharger a few times every tank of fuel. My daily drive is three 10-mile trips 5 and 4 hours between them. I live as in Pensacola, Florida (almost as far west as you can be in Florida.) It is quite humid here and the temperature can get down to 20 in the winter and gets pretty close to 100 daily in the summer.

The factory service manual gives the following information:
SAE 10W-30, SAE 5W-30, SAE 5W-20 (no temperature range was given)
API Service, SG (Energy Conserving II), SH (energy conserving II) or ILSAC (GF-I), SJ or ILSAC (GF-II), or ILSAC (GF-III)
Oil pressure: 43-56psi {3000rpm}
Capacity: 4.2qt (dry), 3.8qt (oil replacement), 4.0qt (oil and filter replacement)

I bought some royal purple 5w-30 (01530) but wanted to get others' opinions before I changed it. I wanted to use this viscosity for thinness on warm up and conglomeration at high temperatures (florida, turbo car). Is there anything at all that would definitely be better than this. I was planning to keep this for six thousand miles to clean out anything that whatever oil/filters used has left in the engine, then change it to the performance street royal purple.

I also got a royal purple oil filter which looks to be indiscernible in quality within the top tier oil filters.

 

[Merkava_4]

Originally Posted By: Brandon1048

The factory service manual gives the following information:
SAE 10W-30, SAE 5W-30, SAE 5W-20 (no temperature range was given)


Given the choice, my preference would be 10W-30 for durability.

 

[aquariuscsm]

Originally Posted By: Merkava_4
Originally Posted By: Brandon1048

The factory service manual gives the following information:
SAE 10W-30, SAE 5W-30, SAE 5W-20 (no temperature range was given)


Given the choice, my preference would be 10W-30 for durability.


Same here. I`d go with the thickest oil it lists.

 

[Eddie]

I would go for the 5w30 to get oil flowing quicker and still have the 30wt protection at running tempeture. A cold start in FL. is still a cold start compared to running tamp. I run 5w30 as the only recomended oil in my CX7 turbo MAzda. I run PP because it is an approved Honda/Acura oil that meets the turbo spec and 10w30 and 5w20 do not.

 

[TFB1]

I agree with Eddie, 5W-30 that meets turbo specs...

 

[Garak]

Originally Posted By: Brandon1048
I bought some royal purple 5w-30 (01530) but wanted to get others' opinions before I changed it. I wanted to use this viscosity for thinness on warm up and conglomeration at high temperatures (florida, turbo car). Is there anything at all that would definitely be better than this.


Better depends upon one's point of view. I tend to stick to conventional where possible, but there's certainly nothing wrong with using a synthetic in a turbo. There's absolutely nothing wrong with RP 5w-30 and it meets all your requirements. It'll do just fine, and if you can get it at a good price, so much the better.

 

[Cooper]

I think the RP Oil/Filter that you purchased should be a great fit for your car. If you are unsure, just run it for 5k and get a UOA done through Blackstone. I would probably bet it will be a good fit for your vehicle.

 

[artificialist]

Originally Posted By: Merkava_4
Originally Posted By: Brandon1048

The factory service manual gives the following information:
SAE 10W-30, SAE 5W-30, SAE 5W-20 (no temperature range was given)


Given the choice, my preference would be 10W-30 for durability.


I do the same with my car.

 

[wiswind]

I would choose the 5W-30 over the 10W-30.......
If the 5W-20 is listed, it might be a good choice as well......some of the 0&5W-20 and 30's overlap in actual specifications.
In other words.......xW-20 and xW-30 each have a MINIMUM viscosity specification, not a maximum, so the 20 could actually be a light 30.

The 0W vs 5W has to do with viscosity when the oil is cold.....with the 0W having better cold flow properties than the 5W.
The 0W often has better base stocks, making it a better choice.

Cold flow is not just at 0 degrees........even room temperature or 80 degrees (F) is COLD as far a motor oil is concerned.
For this reason, the 0W and 5W will give you better lubrication at startup and the first few minutes of operation.

The 20 or 30 in xW-20 or 30 has to do with the temperature of the oil when it is warm....at operating temperature.

A look at HTHS specification (at 150 degrees C ) is an even better indication of how "thick" the oil is at operating temperature in the motor.

The Viscosity INDEX is a number that indicates the oil's resistance to thickening as it gets cooler.
The higher the number the better.

Looking up the specifications on whatever oil you are thinking of using will give you more to compare with than just the xW-xx listed on the container.

My point being....to dispel the myth that the 0W-xx oils are thinner at operating temperature than 5W and 10W.

 

[Garak]

Originally Posted By: wiswind
I would choose the 5W-30 over the 10W-30.......


I agree 100%, and I'm often in the "thick" crowd. If one is using synthetic, what's the point of going 10w-30?


Originally Posted By: wiswind
My point being....to dispel the myth that the 0W-xx oils are thinner at operating temperature than 5W and 10W.


Right again. The PYB 5w-30 I use is thicker at operating temperatures than is the PYB 10w-30. The viscosities at operating temperature of 30 weight oils are to fall within a range, and there are many examples of 5w-30 and 0w-30 oils that are thicker at operating temperatures than 10w-30 oils.