Shorter Oil Change Interval - flat-tappet engines?

[Gunner14]

Originally Posted By: doitmyself
Originally Posted By: Gunner14
I asked him about mixing VR1 with their Max-Life products, and he indicated that the extra detergents/additives in the Max-life products would inhibit the effectiveness of the extra ZDDP at some level.


I don't recall this idea ever being discussed here. Many people choose a HDEO for particular engines (I'm thinking flat tappet and air cooled outdoor power equipment) with the idea that the higher additives (ZDDP in particular) help protect better in these harsher uses.

Now you are suggesting that the higher detergent levels defeat the extra ZDDP? I wonder what the Valvoline tech. meant by "inhibit the effectiveness of the extra ZDDP at some level."



I believe that the above post from A. Harman is what the Valvoline tech rep was was referring to (quote from above):"Diesel oils have harsh detergents that compete for surface coverage with the zddp, making it less effective." I have seen that info covered and discussed at other websites.

 

[mechtech2]

What is the special need?
Why the artificially induced additive numbers?

A good option is to use Lubro Moly.

 

[dnewton3]

Any HDEO that is certified for spark ignition (CJ-4/SM for example) will do just fine. The suggestion that HDEOs will somehow negate the ZDDP to a significant level well beyond that contrasted to a PCMO are generally unfounded.

As always, YMMV ...

 

[Steve S]

Originally Posted By: Gunner14
I just got off the phone with a friend whose an engineer and asked him to help me solve a problem I was having on getting the right level of phosphorus in my oil (want 1000-1100 Phos. in a dedicated gasoline-rated 10w30 oil). I rather not use ZDDP additives; VR-1 and Red line oils are too high in Phos; Mobil 1 is too low; the Rotellas are super-loaded with detergents and not really designed for gas engines; and the many other brand 10w30, the manufacurers don't have the info in their data sheets.

My friend said: "Just use regular 800 ppm phosphorus, SM rated oil in your flat-tappet engine and change the oil at 2 months 2000 miles instead of 3/3000. It will ensure adequate levels of ZDDP present in your oil at all times. The ZDDP is used up as you drive, so just change it sooner..."

If this is true, then this is cheap way to fully protect a flat-tappet engine. Please comment on this plan...
study up the posted used oil analysis and see how much additive is used up. What kind of engine are you talking about.

 

[Steve S]

Originally Posted By: Gunner14
Originally Posted By: doitmyself
Originally Posted By: Gunner14
I asked him about mixing VR1 with their Max-Life products, and he indicated that the extra detergents/additives in the Max-life products would inhibit the effectiveness of the extra ZDDP at some level.


I don't recall this idea ever being discussed here. Many people choose a HDEO for particular engines (I'm thinking flat tappet and air cooled outdoor power equipment) with the idea that the higher additives (ZDDP in particular) help protect better in these harsher uses.

Now you are suggesting that the higher detergent levels defeat the extra ZDDP? I wonder what the Valvoline tech. meant by "inhibit the effectiveness of the extra ZDDP at some level."



I believe that the above post from A. Harman is what the Valvoline tech rep was was referring to (quote from above):"Diesel oils have harsh detergents that compete for surface coverage with the zddp, making it less effective." I have seen that info covered and discussed at other websites.
That hasn't proved out in real life application! I worked at a company that did fleet maintenance using nothing but Delo 400 and the engines would have impressive miles put on them . Our service vans would fall apart with the engines running great. The semis would do the same. The forklifts would get 25,000 plus hours easy. In the 23.5 years of doing fleet work I would without reservation used a HDEO oil if I felt I needed the heavy duty part . HDEOS are the best oils on the market whether syn or dino by far. That said if you do not need the extra it will do no good.

 

[edhackett]

ZDDP is depleted with use. The molecule reacts with the metal surface in response to the heat generated by the metal to metal contact. The molecule is broken down. If I remember correctly some of the daughter compounds also provide protection. Eventually the Zn and P end up in forms that are no longer effective at preventing wear. You won't see this in UOA because they are not analyzing for ZDDP. All you see is the Zn and P regardless of its form.

The idea of detergents interfering with wear protection is just something you don't have to worry about with a properly formulated oil. I'm sure it can happen, but not at levels you'll see in a commercial product. The people formulating the oils are smarter than that.

BTW, your engineer friend is correct. More ZDDP offers longer protection under high metal to metal contact conditions, not more protection. The key is insuring there is a high enough concentration of ZDDP at the contact points.

Use an HDEO with no additional additives and rest easy.

Ed