Oil for a Direct Injection engine?

[supton]

At the risk of fanning flames some of us think 100k is low miles. Since 200k is the new 100k I am not too interested in "works fine at 50k" or somesuch--barely out of warranty and probably only two years old, better not have issues!

Wish I could aim for 300k again.

 

[wemay]

Uderstandable but most of the deposit situations that have occured in DI have been reported from as early as 30k miles.

 

[demarpaint]

Originally Posted By: wemay
Uderstandable but most of the deposit situations that have occured in DI have been reported from as early as 30k miles.


That was my understanding as well. Speaking with two service writer friends and a few mechanics who service newer vehicles confirmed it for me. Still there are plenty of people not reporting any issues at all.

 

[Vuflanovsky]

I agree and I think the problem would likely present itself by 50-75K miles if not sooner. I'm anecdotally hearing about several DI cars at the 100K mile mark from American and Asian makes with no discernible issues...not to say they won't have it at 150K miles.

I'm somehow a bit less concerned about deposits because I have a naturally aspirated DI engine but I really wonder how much disparity is there between an NA direct injection engine and a turbo'd one where these deposits are concerned.

 

[wemay]

I have both. Not worried.

 

[MCompact]

My mildly modded(Mazdaspeed CAI, Hypertech tune) 2007 Mazdaspeed 3 is running great at 154,000 miles, as can be seen here.

The intake valves have never been cleaned.

 

[wemay]

Originally Posted By: MCompact
My mildly modded(Mazdaspeed CAI, Hypertech tune) 2007 Mazdaspeed 3 is running great at 154,000 miles, as can be seen here.

The intake valves have never been cleaned.


+1

 

[SteveSRT8]

Originally Posted By: MCompact
My mildly modded(Mazdaspeed CAI, Hypertech tune) 2007 Mazdaspeed 3 is running great at 154,000 miles, as can be seen here.

The intake valves have never been cleaned.


The issue is always somehow related to the usage. I suspect it is from folks babying and short tripping the vehicle.

Get on it regularly and I bet you have no problems...

 

[MCompact]

Originally Posted By: SteveSRT8
The issue is always somehow related to the usage. I suspect it is from folks babying and short tripping the vehicle.

Get on it regularly and I bet you have no problems...


I have heard that intake valve temperature plays a major role in deposit formation- the higher the temperature, the less deposit formation.

 

[Quattro Pete]

Wife's Q5 is screwed, another words. She has a 3-mile commute. Not only does the engine not stay long enough at operating temp, often times it doesn't even reach it. In summer time her oil temp just hits 140-150F when she gets to work. During winter, it's even worse.

I guess I could try to give it some "exercise" on weekends, but I rarely have a chance to take it on a longer run, and I'm not going to "get on it" while it's still cold.

 

[SteveSRT8]

Originally Posted By: Quattro Pete
Wife's Q5 is screwed, another words. She has a 3-mile commute. Not only does the engine not stay long enough at operating temp, often times it doesn't even reach it. In summer time her oil temp just hits 140-150F when she gets to work. During winter, it's even worse.

I guess I could try to give it some "exercise" on weekends, but I rarely have a chance to take it on a longer run, and I'm not going to "get on it" while it's still cold.


Exactly the type of driver I am speaking of. We all know there are millions of foks who drive to the bank, then maybe a grocery store, etc. All local short tripping.

A hard duty cycle for ANY car...

 

[SilverC6]

I've always been partial to Gp III hydrocracked dino synthetics or a high quality dino for engines known for fuel dilution.

In my son's Mazda RX8, I'm currently using NAPA (Valvoline) Synthetic.

I'm not sure a Gp IV or V synthetic would be the best choice for a direct injection application.

I have always been concerned about miscibility of the excess fuel with PAO/Ester base stocks and maintaining a homogeneous lubricant film.

Certainly whatever you choose, I'd recommend relatively short OCI's.

 

[HangFire]

Originally Posted By: SilverC6
Certainly whatever you choose, I'd recommend relatively short OCI's.


I don't know that I'd recommend that. Short OCI's mean more oil volatility, and for DI engines, more intake valve deposits.

 

[Danh]

Originally Posted By: SilverC6
I've always been partial to Gp III hydrocracked dino synthetics or a high quality dino for engines known for fuel dilution.

In my son's Mazda RX8, I'm currently using NAPA (Valvoline) Synthetic.

I'm not sure a Gp IV or V synthetic would be the best choice for a direct injection application.

I have always been concerned about miscibility of the excess fuel with PAO/Ester base stocks and maintaining a homogeneous lubricant film.

Certainly whatever you choose, I'd recommend relatively short OCI's.








My information may be out of date, but I thought Mazda strongly advised owners of its rotary-engined cars to not use a synthetic or synthetic blend motor oil. I thought RX 7s and 8s were conventional oil only.

 

[benjy]

i often see Ester oils aka Redline touted to protect better with fuel dilution.

 

[FlyPenFly]

Research shows that changing oil frequently is necessary for non-hybrid DI only engines.

Running them "hard" actually causes more deposits because the majority of the buildup is from combustion blow by.

 

[SteveSRT8]

Originally Posted By: FlyPenFly
Research shows that changing oil frequently is necessary for non-hybrid DI only engines.

Running them "hard" actually causes more deposits because the majority of the buildup is from combustion blow by.


This is counter to VW's specific claim about intake valve temp. I am also remembering Mazda saying something similar. Where did you here this info?