Any engine harm or damage possible from using 15wO

[fpracha]

Hello all!

It is being argued (in the HDEO forum) that "The detergents in HDEO reduce the film strength (surface tension) thus the ability of a lubricant to maintain that precious barrier between highly loaded components." [Ducati996]

The response given was that "While your point is taken, I suspect the generally higher HTHS of an HDEO compensates for that." [Garak]

On this subject then, my query remains as follows:
Does it mean that a 15W-40 will damage the engine components and possibly cause "excessive vibrations" (that is, over & above just the CAT converter problems due to higher ash, when used in a passenger car like the Honda Civic (R18 engine, for example) or the Mitsubishi Evo engines, etc. ?

It would be really insightful to hear actual experiences and opinions on this(above).

 

[aquariuscsm]

What I`ve read on here and on other forums,is that diesel/gasoline HDEO`s have additives diesles need to keep them clean that can be abrasive to gasoline engines. I have no idea if this is fact or myth,it`s only something I`ve read.

 

[Zaedock]

Originally Posted By: fpracha
It is being argued (in the HDEO forum) that "The detergents in HDEO reduce the film strength (surface tension) thus the ability of a lubricant to maintain that precious barrier between highly loaded components." [Ducati996]


If this were true, millions of OTR trucks would blow engines pulling 80K lbs up hills.

 

[Zaedock]

Originally Posted By: aquariuscsm
What I`ve read on here and on other forums,is that diesel/gasoline HDEO`s have additives diesles need to keep them clean that can be abrasive to gasoline engines. I have no idea if this is fact or myth,it`s only something I`ve read.


Some of my best UOA's in my junk trail rig have been on Delo SAE30. I'd call it a myth that's right up there with adding tranny fluid to clean your engine.

 

[SwampSurvivor]

Jeep 4.0s show some good wear numbers on 5-40 HDEO ...

 

[Trav]

No damage will be done.
In Europe until ca 1986 the most common engine oil was HDEO 15w40. Millions of cars both gas and diesel ran on it for hundreds of thousands of kilometres without any problems.
Body rot or the TÜV/MOT killed most of them off long before the engines died.

 

[46Harry]

I've been using HDEO oils in gas engines for more than 30 years with no problems. I use Delo 400 15W-40 because that's what we use in our diesel engines. I believe it's a myth that HDEO oils will cause excessive wear in a gas engine. If that was the case, the crankshaft and cam bearings in diesel engines would show excessive wear also. I agree Zaedock, that an 80,000 lb truck pulling a hill would have an engine failure if HDEO oils broke down under a heavy load.

 

[ARCOgraphite]

The only issue would be poor(high) cold viscosity in the winter with a 15w-xx and loss of fuel mileage due to wrong HTHS for a lightly loaded passenger car engine (or motorcycle engine with lightweight components). Try to use the "optimal" viscosity for your engine and driving style. If worried about low/mid saps oils, use any of the new HM oils in the 10w-30 or 5w-30 range that are advertised to have mid/high saps additives for your "highy stressed" passenger car.

 

[Bgallagher]

When I worked landscaping, the mechanic used bulk Rotella 15w-40 in every vehicle. From a couple economy cars, gas trucks, up to front end loaders. All of them worked perfect and all the vehicles had mileage upwards of 150k+. Cold weather pumpability is my only concern but other then that there wouldn't be any issues.

 

[Brons2]

I don't think it would hurt an R18, but I don't think it's necessary either, as they turn in excellent UOA's on 5w20. And it would definitely impact gas mileage around town.

 

[mechtech2]

Let's go all the way to totally non detergent oils.
Like the ones used for lawn mowers and some air compressors.
They do indeed let the additives and oil work better for some loadings, at the cost of cleaning/keeping clean..
But using modern HDEOs in a car is something I would never be concerned about.

 

[Ken2]

Originally Posted By: aquariuscsm
What I`ve read on here and on other forums,is that diesel/gasoline HDEO`s have additives diesels need to keep them clean that can be abrasive to gasoline engines. I have no idea if this is fact or myth,it`s only something I`ve read.
I never heard that. Diesel engine oils do have a higher level of detergents and dispersants to handle the soot that accumulates in the oil. If these are magnesium based, the ash is abrasive. If these are calcium based, the ash is soft.

Unless there are some hydraulic mechanisms in the engine where the HDEO would be too thick for proper function, or if the higher additive level would eventually harm the catcon, there will be no problem with these oils except the harder starting when cold & thick and the slight extra fuel consumption caused by the thicker oil. In any case, why bother? The recommended oil will keep the engine running more miles than the body will hold together.

 

[fpracha]

Originally Posted By: Ken2
If these are magnesium based, the ash is abrasive. If these are calcium based, the ash is soft.
So why is this magnesium abrasive, can you please point to tests or documents on this very important information?

Is it also abrasive to diesels as well, or only to gasoline engines ?

Thanks so much for all your helpful replies

 

[Garak]

Originally Posted By: Trav
No damage will be done. In Europe until ca 1986 the most common engine oil was HDEO 15w40.


Even my 1991 Audi 200 Turbo had a preferred viscosity of 15w-40. It's at over 260,000 km right now.

If it's a dual rated HDEO, I wouldn't worry much, other than whether or not it's in the viscosity ranged specified for the vehicle and for the ambient temperatures expected to be met. Take my old F-150 for example. I have a whack of 15w-40 laying around. I was going to use it in the summer, and use something like a 5w-30 or a 10w-30 HDEO for the winter. Considering how few miles I put on it in the summer, the 15w-40 would be wasted on an OCI less than 1000 km. So, I'm going to give the oil away and get something thinner, HDEO or PCMO.

I'm not worried as to whether or not it's an HDEO. I'm more concerned about not getting enough use out of the thicker 15w-40 before I have to change it out for a suitable winter viscosity, even if that winter viscosity is also an HDEO (which it probably will be).