Should I expect nasty black smelly oil?

[JohnnyJohnson]

First OIC on my 2022 Mazda CX-5 just less than 4088 miles UOA showed very little fuel and the oil was dark but not black.

 

[Brian123]

This is my first GDI engine. I always do my own oil changes. I have read fuel dilution and carbon/soot are major issues with GDI engines.
Should I always expect the oil to come out pitch black and smelling of fuel or ?

What has been your experiences?

Depends, what Oil are you using?

 

[ZZman]

Depends, what Oil are you using?

Will use HPL premium 0w-40

 

[ZZman]

Regular 87 octane fuel with that HyunKia turbo engine?
Keep us updated on how good it runs on 87. Carbon will likely increase using it. HPL strength is on your side.

Can you explain to me how carbon is related to octane?

 

[LineArrayNut]

Hyundai 2.0 turbo motor. It will be almost exclusively short tripped as wife's car. Maybe 5,000-7,000 miles a year. 5,000 mile oci. Usually top tier reg unleaded fuel. Driven normally. Will be using HPL 0w-40 premium oil this first oil change. It recommends 5w-30 but also says 5w-40 is ok too.

Yes, it will.

 

[doublebase]

Admittedly the first time I owned a GDI engine I did notice the fuel smell and how quickly the oil turned dark in the engine. And I was mostly a highway commuting, eighty miles a day, driver. 2018 Chevy Silverado.

 

[Azimuth]

Short tripped? Don’t go XW40. Go Xw30.

What's the reason for going with a lower viscosity oil for a short tripped engine?

 

[edyvw]

What's the reason for going with a lower viscosity oil for a short tripped engine?

There is less resistance at KV40. Oil will flow better at lower temperatures. One might not warm up oil at all to operating temperature during short trips. Also, if it is Euro XW30 oil, with MB229.52, HTHS is anyway at minimum 3.5cP. So, protection wise, xW30 or XW40 with MB229.5X, BMW LL01/04, VW 504.00/507.00, VW502.00, VW511.00, has the same minimum HTHS. Rule of thumb: As thick as necessary, as thin as possible.

 

[LineArrayNut]

On my hyundai, yes, black as a diesel motor oil and reeks of gasoline.

 

[wlk]

On my hyundai, yes, black as a diesel motor oil and reeks of gasoline.

My wife's Honda Civic 1.5t was the same.

 

[gfh77665]

Do a 5000 mile UOA to give you a baseline. Adjust up or down accordingly.

 

[02zx9r rev2]

Every oil change I have ever done, oil on dipstick was honey or caramel colored and the Drained oil was black. No matter if 3K or 5K miles

 

[MrBaumTastic]

Can you explain to me how carbon is related to octane?

As someone who uses 90 or higher in my Sportage, mainly for the way it runs smoother, and I have no engine ping/spark knock (detonation or pre-ignition whatever it's called lol), I saw this and began to wonder:

"octane ratings definitely shouldn't affect carbon deposit formation but could it affect fuel dilution?"

It's just a thought, but it's possible right? Because, in these GDI engines the higher pressure and higher heat could cause pre ignition and unburnt fuel to get mixed with the oil more so than if higher octane fuel is used which burns more completely.

 

[thetricky]

I've owned 4 GDI vehicles at this point. Two Nissans and two GM products. Three of them V6s and one 4cyl. All non-turbo. All of them create oil that is nasty looking and smelling compared to the dozens of port and throttle body fuel injected engine I've owned in past.

I realize looks and smells don't necessarily mean anything bad, but how could that possibly be good for extended drains?

Again, without an analysis you have no idea if the oil is still serviceable or not, regardless of color or smell. HPL and Amsoil are designed to take this beating and extend changes safely.