Longest you'd extend oci on a 15W-40 HDEO, on a GAS engine?

[FCD]

Let's assume a 15W-40 HDEO , Conventional ofcourse, being used in an older naturally aspirated fuel injected gasoline engine.
Mostly easy highway driving and 90% of the times the engine is started it reaches full operating temperature.
The oil in question is API SL/ CI-4, and ACEA E7.
Would 7500km ( 4500 miles ) , or even 10.000km ( 6000 miles ), be a stupid idea?

 

[Chris142]

I would guess 6000m minimum.

 

[bullwinkle]

Only UOA would answer that question. I would imagine 10K KM would be doable, as long as your carburetor isn't dumping too much gas.

 

[Alex_V]

Unless the engine has a design or flaw that is hard on oil or sensitive to longer intervals, 5,000 mi. should be perfectly safe and UOA from there.

 

[JeffKeryk]

Us iron headed, high compression 60's muscle car guys have been using Rotella for years as a hedge against flat tappet cam wear.
It is currently in my 68 L36 Corvette Roadster and 65 90K original 4-4-2.

 

[maxdustington]

Originally Posted by JeffKeryk
Us iron headed, high compression 60's muscle car guys have been using Rotella for years as a hedge against flat tappet cam wear.
It is currently in my 68 L36 Corvette Roadster and 65 90K original 4-4-2.
Pic please! GM muscle cars are mah favorit. A friend of my Dad's had multiple Cutlasses when I were a lad, so I have a particular fondness for the 442.

Not sure about extended OCI with a carb, but isn't the OTR truck market known for long OCIs? I know it's a completely different application but I would assume that a quality 15W40 HDEO would have the higher TBN needed for a long OCI. If you can avoid short trips that should help with the fuel dilution from the carb.

 

[92saturnsl2]

I wouldn't hesitate to run an extended drain, provided the engine is in good shape with no fueling issues or the like. 7,500 should be easy, 10k if you're adventurous.

Here's a handful of UOA's where I've used HDEO oil, albeit 10w-30's not the 15w-40 you're considering. One is a for a 2000 Bonneville I had w/ the 3.8L supercharged engine. Other two are a Dodge Caliber SRT4 with 2.4L turbo engine. Neither driven very conservatively, the HDEO held up extremely well in all instances I've used it.

 

[BrocLuno]

OP's vehicle has fuel injection. All the carb talk is not relevant ...

State of Cali Fleet Admin did studies years ago that came back with 6,000 miles and filter every other as the most cost effective and efficient change interval. The fleet included carb'd cars and trucks and FI vehicles. Many, many of those vehicle were running on HDEO as that was what was supplied by the barrel to the local State Garage, or facility.

All us 3K kids thought they were somewhat crazy, but time and persistence has proven them right. The fleet goes to somewhere between 150,000 and 250,000 miles before being auctioned off. Some of the big rigs get auctioned purely on age as mileage does not matter so much for them.

HDEO's can go 25,000 miles in a Cummins or a CAT. Why would anyone have an issue at 6,000 miles in a good running FI vehicle ...

I'd be more inclined to worry about other stuff not being noticed due to time interval before anyone crawled under the vehicle on a 6,000 mile change interval ...

As long as you are good about looking after stuff, just go the distance

 

[FCD]

Originally Posted by bullwinkle
Only UOA would answer that question. I would imagine 10K KM would be doable, as long as your carburetor isn't dumping too much gas.

It is Fuel Inejcted, ( Mechanical Bosch K-Jet ) , runs pretty rich when cold but otherwise it doesn't sump huge amounts of fuel into the oil.

 

[FCD]

Originally Posted by BrocLuno
OP's vehicle has fuel injection. All the carb talk is not relevant ...

State of Cali Fleet Admin did studies years ago that came back with 6,000 miles and filter every other as the most cost effective and efficient change interval. The fleet included carb'd cars and trucks and FI vehicles. Many, many of those vehicle were running on HDEO as that was what was supplied by the barrel to the local State Garage, or facility.

All us 3K kids thought they were somewhat crazy, but time and persistence has proven them right. The fleet goes to somewhere between 150,000 and 250,000 miles before being auctioned off. Some of the big rigs get auctioned purely on age as mileage does not matter so much for them.

HDEO's can go 25,000 miles in a Cummins or a CAT. Why would anyone have an issue at 6,000 miles in a good running FI vehicle ...

I'd be more inclined to worry about other stuff not being noticed due to time interval before anyone crawled under the vehicle on a 6,000 mile change interval ...

As long as you are good about looking after stuff, just go the distance

Interesting info.

 

[Linctex]

Originally Posted by FordCapriDriver

It is Fuel Inejcted, ( Mechanical Bosch K-Jet ) , runs pretty rich when cold but otherwise it doesn't sump huge amounts of fuel into the oil.


You can run HDEO in any gasoline engine (carb or FI) for well over 10,000 miles as long as you don't have any excessive dilution.

If you start the engine and let it run 24/7 - like an irrigation pump - then that oil will last for an unreal amount of time.

 

[hpb]

10,000km easily. Recommended OCI on most vehicles in Oz has been 15,000km since the early 2000's, and the oil you're using is no doubt better than we were using back then.

 

[zeng]

Did 10,000 km, with a carb engine.
Verified with blotter spot tests.
Could have gone on.

 

[PeterPolyol]

10K KM/6000 miles is fine for a non-HDEO oil let alone a high TBN HDEO

 

[Garak]

10,000 km would be easily attainable here.

 

[BrocLuno]

I forgot to add that I have run HDEO in seldom used ranch trucks for up to 5 years w/o change. Nothing bad happens as long as they get up to temp when started

 

[userfriendly]

25% past OLM on 2013 GMC 1500 5.3L. Previous UOA at 90% OLM (12,000 kms) showed the oil could go further. Duron 15W40 CJ-4.

 

[FCD]

I might try going for 7500km first, with a good oil filter like a Bosch or Mahle.

Now, before that, in November or December i've already planned to change the hydraulic lifters in it, so will probably do a couple short oci's after that so i don't have too much metal particles floating around in the oil.

After that i plan to take the car to the local K-Jetronic specialist so he fine tunes the injection which is probably running somewhat rich right now....

Then i'll start to try extending the OCI's.

 

[dnewton3]

A UOA will tell you. Start there.

 

[FCD]

In most parts of Europe it's not as simple as sending a sample to blackstone, i don't know of any oil labs in Spain and i'd probably have to send it off to Germany or the UK.