Oil recommendation for build Mazda Speed 6

[FatOldMan]

So, I’ve read a lot of threads. People like M1, PP, RL, Amsoil, etc. All good oils.

So, the application is a Mazda DI. Engine recently built. Car is a 2007. Will use break-in oil at first. Stock recommendation is 5w-30 I believe. Not concerned about Mazda warranty, that is long long over.

So, fuel contamination is known for these cars. Though I am adding an air/oil separator to help decrease oil contamination. This engine also known for carbon deposits given that it is DI. However, I am going to be using secondary fueling, with something called a Split-Second controller. So, the secondary fueling is with additional conventional injectors installed into the intake manifold. So that should help mitigate the carbon issue at least to some degree.

So, the car is turbo stock, but I’m getting a bigger turbo, along with the additional fueling and tuned for E85 gas. I’m using a Precision Turbo 6062. I’m told that I should be able to get about 600 WHP. But, I don’t have it yet, car is still being put together. But, thinking about what oil I would use after break-in?

I’m leaning towards with Motul Sport 5w40, or Renewable Lubricants BioSynXtra HD 5w-40. I have read that the RL is noted for being best-in-class handling of fuel dilution. Opinions?

 

[JohnnyJohnson]

I’m leaning towards with Motul Sport 5w40, or Renewable Lubricants BioSynXtra HD 5w-40. I have read that the RL is noted for being best-in-class handling of fuel dilution. Opinions?

At $50 plus a jug how could you go wrong LOL

 

[FatOldMan]

At $50 plus a jug how could you go wrong LOL

Well, to tell the truth, I’m having some buyer’s remorse over the project, spending too much money. But, its money spent. So, to spend a few extra pennies on the oil is insignificant.

I did ask my builder what oil he recommended. His first response was just a high quality synthetic to reduce chance of LSPI. He said something like Mobil 1 and sent a link to the M1 page on LSPI. And he first said 10w-40 weight. But then suggested as a higher end option Driven Racing Oil 15w-50. I never heard of DRO, I guess I could search for it here.

The thing is, I’m surprised at the weight recommendations, 10w-40 to 15w-50. I thought the general trend is towards lower viscosity, though it is an early 2000 era engine design. Even so, I was expecting him to say either the stock 10w-30 or Euro 5w-40. Just as a general rule, what viscosity oil do turbos generally like?

 

[Graham Piccinini]

Mobil1 15w-50. Available in any Wal-Mart at a good price (under $25/5qts), local highly built&tuned Mitsu Evo guys swear by it. Same with local built&tuned Euro clubs, and Muscle car guys. Those who experience colder weather (NC/TN/VA mountains) end up switching to Mobil1 0w-40 for colder months. Some mix in a quart or two of Mobil Racing 0w-50/5w-50.

P.S. Sorry, don't have enough Mazdaspeed guys in Charlotte NC to see what they use...

 

[FatOldMan]

Thanks for the advice. I was thinking about that, the Mobil1 15w-50. Still seems on the thick side to me, but it does seem like people use it. There are also 5w-50 oils like Amsoil that I can get for cheaper than the Motul but more than the Mobil1.

I'm in Houston, so, "cold" for me is like the 40's. (F). No need for winter tires or winter oils.

 

[Graham Piccinini]

Thanks for the advice. I was thinking about that, the Mobil1 15w-50. Still seems on the thick side to me, but it does seem like people use it. There are also 5w-50 oils like Amsoil that I can get for cheaper than the Motul but more than the Mobil1.

I'm in Houston, so, "cold" for me is like the 40's. (F). No need for winter tires or winter oils.

In that climate and with power mods you'd be hard pressed to find any issues with running Mobil1 15w50. Probably the best option available for the price, considering climate and application.


Mobil1 15W50
Flash Point : 232 C
Pour Point: -39 C
Hi-Temp Hi-Shear Viscosity @ 150 C: 4.5
Kinematic Viscosity @ 100 C: 18
Kinematic Viscosity @ 40 C: 125
Total Base Number: 9.98
Viscosity Index: 160

Mobil1 0W40
Flash Point : 226 C
Pour Point: -54 C
Hi-Temp Hi-Shear Viscosity @ 150 C: 3.6
Kinematic Viscosity @ 100 C: 12.9
Kinematic Viscosity @ 40 C: 70.8
Total Base Number: 12.6
Viscosity Index: 186

 

[Jackson_Slugger]

So, I’ve read a lot of threads. People like M1, PP, RL, Amsoil, etc. All good oils.

So, the application is a Mazda DI. Engine recently built. Car is a 2007. Will use break-in oil at first. Stock recommendation is 5w-30 I believe. Not concerned about Mazda warranty, that is long long over.

So, fuel contamination is known for these cars....

Been awhile since I was in a Speed6. But should be noted that the redesigned 09' Mazda 6 allowed for "5W-40" in the manual, for the 3.7L at least...