07 Mazda CX-7, 2.3L Turbo, Quaker State RPM 10W-30

[Last_Z]

This is the latest on my car:

- 07 Mazda CX-7, 2.3L Turbo, 6-speed auto
- Quaker State RPM 10W-30, which had a manufacture date of 2005
- Somewhere between 3.5 to 4 months of use
- Wix cartridge type oil filter
- STP air filter
- This oil has a 1600 mile trip. About half is highway miles.
- Drving style is never predictable. It'll go from babying it to WOT in the blink of an eye. Lots of WOT runs!
- I used 89 octane during this interval a lot. It calls for 91 or better.

Other than the inevitable fuel, I am VERY pleased with this report. Silicone is beyond this world....it just doesn't get any better. Wear is extremely good. Very happy overall!!

Comments, remarks, hate mail and all else; just shoot!

EDIT: Running PP 10W-30 with Motorcraft oil filter and STP air filter.

 

[buster]

Looks great, but the oil did thin down to a 20wt. It didn't impact wear at all.

 

[Last_Z]

There is not much I can do about the fuel! Unless someone comes out with a leaner tune for this engine, DISI engine owners are going to have lots of fuel in their oil. I could try a 5W-40 in the summer and see what that does.

 

[tackleberry625]

looks like a good oil/engine combo.

 

[badtlc]

I'm not sure why you are skimping on the gas. It would only cost you 3% more to run the proper fuel and therefore getting the HP you paid for.

Nice wear, but yeah...Fuel is a big concern for these DISIs.

 

[Last_Z]

If I had a penny every time.........

Anyway, I have gained MPGs with 89 over 93 especially in colder months. Never had a problem! I have run 91-93 since last OCI though.

Rick

 

[SubLGT]

Very good UOA. But 89 octane+turbo+lots of WOT runs is not a good formula for engine longevity.

 

[Scott P]

The fuel dilution doesn't seem to affect the wear. I saw the same results in my last UOA on my Speed6. I know they have a couple new ignition systems to help get a more complete burn from the fuel and I'm curious if that would help reduce teh excess fuel.

 

[REDDOG]

I used to be so paranoid about fuel dilution during the winter time, as I live in a cold climate. After seeing so many great reports posted here with fuel well over 1% I don't worry about it any more.

Great report, thanks for posting,

REDDOG

 

[Last_Z]

REDDOG,

The fuel is due to the direct injection on these engines. Even in the summer, it will show lots of fuel.

SubL,

I ran 87 last summer and abused the car purposely. I couldn't get it to ping or detonate. The throttle on these DISI engines is drive-by-wire and the ECM has a lot of control over it. When you step on it and the ECM sees something weird, no matter how small, it will close the throttle to prevent damage. Just because you "floor it", doesn't mean you get WOT.
I have been running 93 octane though.

Rick

 

[Last_Z]

One thing I forgot to mention when I posted this was that the inside of the air box was coated in very light dust. It was surprising to see such low silicone and wear numbers.

 

[JAG]

Was the dust on the post-filter part? If so, either the STP air filter needs improvement or there is a leak in the seal around the perimeter.

My VW has used Mann air filters for 98K miles and the post-filter part of the air box has never had any visible or feel-able dust on it.

Maybe your airbox "filtered" out much of the dust. Coat the surfaces in Vasoline and it may do even better.

The UOA looks good which is not easy in this engine as you know. I wish we knew what the TBN and TAN were. It's hard to know how stressed the oil is with the data given. Testing on DI gas engines for research (by ?? can't recall) caused the researchers to conclude that the engines produce some soot in the oil which pushes them a little closer to being like diesel engines in that sense. They also said that oil quality played a large role in keeping the intake valves clean. Obviously the turbo causes additional lubricant stress.

What is the PCV system like on your engine? By that I mean: routing, ease of inspection, level of complexity, etc. Does is get highly oiled and does it get puked on with a carbon-rich mess? I had to replace my VW's PCV system (costing $500) because it got clogged with carbon-rich deposits. It is quite complex and very difficult to remove it all. I hope Mazda's DISI engines aren't prone to that. If so, there will be issues eventually for many owners.

 

[Last_Z]

JAG,

The light dust was indeed on the post-filter side of the box; which is why I was so surprised with the silicone and wear numbers. I did install a new filter though.

I didn't do a TBN/TAN because I already know this engine is hard on oils and I don't plan on going further than 5k miles anyway.

I have asked other Mazda DISI engine owner about the location of the PCV valve, but so far no one can locate it. I tried following the underhood diagram, but no luck. All I can see is some sort of sensor on the valve cover, but nothing else. I'll go to the dealer soon and ask them.

Rick

 

[Max_Wander]

Fantastic report! Everything has settled down perfectly, looks like bearing/overlay has seated nicely. 10w30 is a good oil for this IMO. Also mazda now recommends that you can run Regular gas at reduced performance in the CX7, which is just fine for commuting and such. Many people who have bought them have haplessly used regular anyway, without effect. ECU tune is quite safe on these engines.

 

[Nederlander75]

Guess that answers my pondering if a 10w would reduce the fuel dilution.

 

[Last_Z]

Thanks Max! Things have indeed settled very nicely. I'm currently running PP 10W-30. I really want to run Valvoline HM 10W-30 after this OCI.

Nederlander, I do think the 10W can have an impact on fuel dilution.

 

[Nederlander75]

Originally Posted By: Last_Z
Thanks Max! Things have indeed settled very nicely. I'm currently running PP 10W-30. I really want to run Valvoline HM 10W-30 after this OCI.

Nederlander, I do think the 10W can have an impact on fuel dilution.


It works on my EVO to keep out start up and cold fuel dilution is what I was relating it to. Different animal.