Don't have an OLM ???

[RamFan]

Blast from the past! I completely forgot about TooSlick. As usual, great post Shannow!

 

[CR94]

Originally Posted by Bryanccfshr

It is more accurate if you track mileage for the entire OCI. ...

Yes, definitely so (for the formula that uses "mpg"). In fact, that's a thinly disguised version of one of my pet ideas, that for any particular oil+vehicle combination, change intervals would be better defined if based on total fuel consumed since the previous change, instead of simply on distance traveled. In that case, the other terms in the formula are essentially constants, but variations in idle time, weather, short trips, towing, etc. are reflected in the fuel used, hence in mpg. The displacement/power term overly favors large, low-specific-power engines (e.g., pre-1950 tech), methinks.

 

[Bryanccfshr]

Originally Posted by CR94

Originally Posted by Bryanccfshr

It is more accurate if you track mileage for the entire OCI. ...

Yes, definitely so (for the formula that uses "mpg"). In fact, that's a thinly disguised version of one of my pet ideas, that for any particular oil+vehicle combination, change intervals would be better defined if based on total fuel consumed since the previous change, instead of simply on distance traveled. In that case, the other terms in the formula are essentially constants, but variations in idle time, weather, short trips, towing, etc. are reflected in the fuel used, hence in mpg. The displacement/power term overly favors large, low-specific-power engines (e.g., pre-1950 tech), methinks.

I think it is about right. Higher power density producers such as GDI and turbo are penalized while more traditional engines are easier on oil. A 2.7 ecotech will wear oil faster than a 4.6 modular. I don't think that Direct injection is penalized enough. For the Micro soot and fuel loading. But like dusty roads, GDI is a penalty and restriction of its own that oil can't fix.

 

[CR94]

Originally Posted by Bryanccfshr

... I think it is about right. Higher power density producers such as GDI and turbo are penalized while more traditional engines are easier on oil. A 2.7 ecotech will wear oil faster than a 4.6 modular.

But the formula also says your modern 4.6 Ford "will wear oil faster" than a similar size circa 1960 Ford 292³ (~4.8 liter) V8. I don't think so! Oversimplified rules-of-thumb ignore a lot of important factors.

 

[Bryanccfshr]

Originally Posted by CR94

Originally Posted by Bryanccfshr

... I think it is about right. Higher power density producers such as GDI and turbo are penalized while more traditional engines are easier on oil. A 2.7 ecotech will wear oil faster than a 4.6 modular.

But the formula also says your modern 4.6 Ford "will wear oil faster" than a similar size circa 1960 Ford 292³ (~4.8 liter) V8. I don't think so! Oversimplified rules-of-thumb ignore a lot of important factors.

Your reaching way back to carnerated engines to find an example that fits. Compare the 4.6 to the 5.4 modular or the current 5.0 coyote. this alogorythm was written with fuel injection in mind, but like I already mentioned I think it would have to change to be accurate with Gdi or TGDI. Probably simulate to having a carberator in penalty. You can reverse engineer the formula with accurate fuel dilution UOA's from gdi. But first we would need accurate fuel mileage numbers and fuel dilution readings.

 

[Gokhan]

Originally Posted by Shannow

Was looking for something I found yesterday regarding fuel economy and oil change interval...which got me to the machinery lubrication article here. https://www.machinerylubrication.com/Read/29117/oil-change-intervals Which had three theories for predicting max oil change interval based on engine parameters, one of which twas the "Kublin" method, mentioned here https://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=35017 Note that Ted Kublin used to be on BITOG as TooSlick (Dixie Synthetics)...the spacebears link is broken, but I found it on the wayback machine... https://web.archive.org/web/20070701115905/http://neptune.spacebears.com:80/cars/stories/interval.html The calculators even work...but here's the formulae that have been variously used, and demonstrated their "worth" in UOA. So those of you who DO UOA's have a compare with where these suggest that you can go...

It completely disregards the base-oil type, which is, of course, crucial in determining the OCI length. Not to mention detergent type, sulfur level in fuel, emissions-certification level of the engine, other engine parameters, and dust etc. conditions. Driving conditions are only somewhat accounted in the first formula. All these affect TBN-depletion rate dramatically. None account for the oxidation rate. You trash my BOQI and then waste time on and post junk science like this?

 

[Shannow]

Originally Posted by Gokhan

[ It completely disregards the base-oil type, which is, of course, crucial in determining the OCI length. Not to mention detergent type, sulfur level in fuel, emissions-certification level of the engine, other engine parameters, and dust etc. conditions. Driving conditions are only somewhat accounted in the first formula. All these affect TBN-depletion rate dramatically. None account for the oxidation rate. You trash my BOQI and then waste time on and post junk science like this?

I've noted that the OLM on my Colorado, I don't have to type the BOQI into come oil change. Why is that ???

 

[4WD]

Perhaps on purpose … Like when they come from the factory with a middle of the road semi … and first two oil changes (or more) are free … or people keep bringing them to the dealer for an oil change deal … Or how about spec 0w20 Dexos for base oil confidence … increase the sump capacity … new oil pump system with coolers … add piston oil jets … So I'm fine with OLM knowing all that got done …

 

[CR94]

Originally Posted by Bryanccfshr

Originally Posted by CR94

But the formula also says your modern 4.6 Ford "will wear oil faster" than a similar size circa 1960 Ford 292³ (~4.8 liter) V8. I don't think so! Oversimplified rules-of-thumb ignore a lot of important factors.

Your reaching way back to carnerated engines to find an example that fits. ...

Why not? Nothing in the formula, as presented, says I can't ---even though I don't know what "carnerated" means. Such formulae are (as Gokhan says) close to "junk science" without a lot of conditions and provisos attached.

 

[Gokhan]

Originally Posted by Shannow

I've noted that the OLM on my Colorado, I don't have to type the BOQI into come oil change. Why is that ???

You need a firmware update?

 

[Bryanccfshr]

"Carbureted" was not picked up by my IPAD spell check..it could be the term is not used frequently anymore. The alogorythms are sound With port injected engines which were the contemporary technology at the time the alogorythm was developed. Time is always a factor with technology. u

Originally Posted by CR94

Originally Posted by Bryanccfshr

Originally Posted by CR94

But the formula also says your modern 4.6 Ford "will wear oil faster" than a similar size circa 1960 Ford 292³ (~4.8 liter) V8. I don't think so! Oversimplified rules-of-thumb ignore a lot of important factors.

Your reaching way back to carnerated engines to find an example that fits. ...

Why not? Nothing in the formula, as presented, says I can't ---even though I don't know what "carnerated" means. Such formulae are (as Gokhan says) close to "junk science" without a lot of conditions and provisos attached.

 

[StevieC]

This is excellent for non OLM equipped vehicles. Thanks!

 

[DGXR]

I have run these OCI calculators using my 2006 Tacoma 2.7 2TR-FE which is all stock and runs awesome with 150,000 ODO miles. The calculator results are between 8,000-11,000 miles, these are reasonable numbers. This includes TBN starting points from 8 to 11 because I use whatever 5w30 synthetic is on sale, usually M1 / M1EP, Valvoline Syn or PP. OEM recommends 5,000 mile OCI with conventional 5w30. Currently I'm doing 7500 mile OCIs with mostly easy miles on clean pavement, and the drained oil still looks pretty clean. Soon I will begin running slightly oversize filters which will increase my comfort going longer... looking at 8500-9000 miles with a 5.5 quart sump. I won't go any further because this 2.7 engine is becoming known for long-term piston ring coking (and oil burning) around 150,000 miles and I don't need that kind of trouble. I guess what I'm saying is that 8500-9000 would be the limits of my comfort zone. I'm very easy on this truck and take very good care of it, plus it is not considered an engine that is "hard on oil." So I'm not worried about going a bit longer than 7500 miles on a good synthetic.

 

[CR94]

The Kublin method yields 26.7k miles for me. Sure ... ... and about 18.5k for my '81 Mazda, assuming a (more modern) TBN of 9.

 

[ka9mnx]

FYI. I ran the Heidebrecht model since, according the to article, seems to be more accurate. Here are my results using Mobil1 HM 5w30 since I use it and I know the BN: Ranger 8,000 miles (OM says 5,000) 4Runner 9,000 miles (OM says 7,500) Dodge Van 6,000 miles (OM says 7,500) F150 7,500 miles (OM say 7,500) So, looks close...

 

[Bryanccfshr]

My kublin results with known oils The Tacoma with an ideal 22 mpg and m1 afe 0w20 only 9100 miles With a more representative 18.5 mpg average I could go 7680. With M1 0w40 22 mpg= 13000 18.5 mpg =10990 It seems the Toyota 10k OCI recommendation Is optimistic on regular 0w20's with this truck. Checking my wife's 4 runner which is lower power density And only shows 16.5 mpg on this service interval( honest gas mileage for my wife's driving habits..) Mobil 1 afe is good to 7900 miles Mobil 1 0w40 fs is good to 11300 Basically severe service schedule for me which I was doing anyway.

 

[Gokhan]

The Heidebrecht model has an adjustable parameter that you need to guess so that the resulting OCI makes sense. Once you have an adjustable parameter you have to guess to make the formula work, what's the point of having a formula? The TBN-depletion rate depends on the base-oil type, which tells you how fast the acids are formed by the oxidation of the base oil, and many other things, including the amount of antioxidant used in the oil, which are not accounted for in any of the formulas. A Group II oil with TBN = 13 and a PAO oil with TBN = 13 will result in OCIs differing by about a factor of three. All formulas in the original post are junk science at best.

 

[Bryanccfshr]

Tooslick who originated the formula. The website formula does not represent his intentions. And he would agree with you. Base oils (ability to resist oxidative breakdown and change of viscosity)and dirt and soot contamination matter. https://www.bobistheoilguy.com/foru...e-ultimate-oil-change-strategy#Post35017

Originally Posted by Gokhan

The Heidebrecht model has an adjustable parameter that you need to guess so that the resulting OCI makes sense. Once you have an adjustable parameter you have to guess to make the formula work, what's the point of having a formula? The TBN-depletion rate depends on the base-oil type, which tells you how fast the acids are formed by the oxidation of the base oil, and many other things, including the amount of antioxidant used in the oil, which are not accounted for in any of the formulas. A Group II oil with TBN = 13 and a PAO oil with TBN = 13 will result in OCIs differing by about a factor of three. All formulas in the original post are junk science at best.

 

[fdcg27]

If I run the Kublin calculation for my '12 Accord, I get a number within a few hundred miles of what the OLM would recommend. Kind of interesting.

 

[Shannow]

Originally Posted by fdcg27

If I run the Kublin calculation for my '12 Accord, I get a number within a few hundred miles of what the OLM would recommend. Kind of interesting.

Yep, I posted it up a) because I found it again after all these years, and there's a lot of people who never were part of the really good discussions that we used to have here; b) because enquiring minds such as yourself will fiddle with it. Not claiming scientific basis for it although the metrics used do sound sensible in determining oil life.