New and Used Car Talk Reviews Hot Cars Comparison Automotive Community

The Largest Car Forum in the Philippines

Page 3 of 3 FirstFirst 123
Results 21 to 26 of 26
  1. Join Date
    Sep 2005
    Posts
    33
    #21
    Quote Originally Posted by amacatan
    Hello,

    Hingi lang ako comments on using semi-synthetic oils on diesel engines. I currently use regular oil on my diesel ride pero parang gusto ko i-try yung semi-synthetic. Semi-synthetic lang kasi I find the fully-synthetic oils too expensive e. Also, even if I decide to change to semi-synthetic oil I still would want to change it regularly at 5K intervals.

    Lastly, I have read somewhere that when you switch to synthetic oil you will not be able to go back to using regular oil? Is this true?

    Thanks!
    di ako naniniwala na dapat synthetic (or semi) oil ang lagay sa diesel engines eto mga rason kung bakit
    - diesel engine is a dirty engine by nature (even b/new diesels will blacken new oil in a few hundred km drive only) and should be oil changed every 5k km thereby negating the longlife adv. of synthetic oils.
    - diesel engines are high pressure powerplants (2x pressure than that of gas engines) thereby it needs thicker viscosity oils, synthetic oils have very thin and low number viscosity.
    - the only reason why dealers will convince you to put synthetic oil in your diesels is they get more profit on these expensive oils, think about it mga pre.

  2. Join Date
    Jul 2003
    Posts
    511
    #22
    Quote Originally Posted by slipstreamer
    di ako naniniwala na dapat synthetic (or semi) oil ang lagay sa diesel engines eto mga rason kung bakit
    - diesel engine is a dirty engine by nature (even b/new diesels will blacken new oil in a few hundred km drive only) and should be oil changed every 5k km thereby negating the longlife adv. of synthetic oils.
    - diesel engines are high pressure powerplants (2x pressure than that of gas engines) thereby it needs thicker viscosity oils, synthetic oils have very thin and low number viscosity.
    - the only reason why dealers will convince you to put synthetic oil in your diesels is they get more profit on these expensive oils, think about it mga pre.
    I agree to that! Diesel Engine needs thicker oil. I'll already tested 3 oils the Castrol CRD 15W40, Delo Gold Multigrade 15W40, Delo Gold Monograde SAE 40. The best and silent, smooth oil is the Delo Gold Monograde SAE 40. This is the oil that fits my L300 Van 4D56 Engine. That's my observation.

  3. Join Date
    Oct 2002
    Posts
    3,013
    #23
    mobil 5w50 for a gen 2 diesel pajero is ok or not?

  4. Join Date
    Aug 2005
    Posts
    4,293
    #24
    hello, for diesel i will stick with any 15-40w if light truck and suv 40HD cargo trucks.. I tried na Havoline Energy 5-30w with my Trooper but medyo kinain ang oil so balik ako to original 10-30..very sensitive ang Isuzu trooper 4Jx1. No big difference semi-synthetic and mineral based diesel oil, chang oil lang every 5000Km..

  5. Join Date
    Sep 2005
    Posts
    1
    #25
    The terms "synthetic", "semi-synthetic" and "mineral" refer to the base fluid from which a lubricating oil is blended. By "synthetic" we mean something that is man made and not naturally occuring, so it is a product of laboratory experiments which explains the high cost. "Semi-synthetic base oils" are more often than not mineral based but are more refined to the point of almost having the same properties of "synthetic" ones, which again explains its higher price. A good example is Caltex's Havoline Energy whose base oil is considered as being under BASE 3 that undergoes an extra stage in the refinery process (thermal cracking and isodewaxing).

    Consider the kinds of base oils as 3 kinds of batallions of soldiers, the first being made up of human beings (mineral based), the second consists of human beings brainwashed to engage in war until death (semi-synthetic) and the third as having androids as in the movie "Universal Soldier" (synthetic). In the battle field (operating conditions in the engine), some of the soldiers in the first batallion aside from being killed, "can" think of giving up and eventually retreating due to hardship and casualties. This will hasten the rate of decrease in number of heads standing their ground. In the second batallion, non of them will not give up but because of their human form "can" still die if shot in a vulnerable part of the body (normal rate of decrease in number of heads). But in the third batallion, defeat is doubtful because the soldiers can withstand both mental and physical torture (prolonged rate of decrease). I hope you guys get the analogy.

    Sir slipstreamer voiced out his reasons for not believeing in synthetic or semi-synthetic oils. Comments ko lang sir if I may:
    -Diesel engines are indeed "dirty" by nature lalo na kung madalas dumaan sa traffic (stop-go driving) which leads to an increase in production of water during combustion. Since this is the case and given na 5k intervals ang change oil, di ba mas ok na ang type ng oil na gamitin ay lesser ang rate of degradation ng protective properties (one of the benefits of semi-synthetic over mineral based)? Mas panatag ang loob mo?
    -Diesel engines are high pressure powerplants that need more viscuous oils. But synthetic oils are not very thin and have low viscosities. Consider the SAE rating of the Pertua synthetic oil: 15W-40. It still has the 40 rating in addition to 15W. This means that it has protective properties during cold starting in addition to performing as an SAE 40 oil in normal operation. For as long as it has the 40 rating, the oil will be viscuous enough to protect the engine in normal operating conditions.
    -Yes, stores get better margins on synthetic oils, but to give you an idea, polyalphaolefins (PAO's) used for synthetic oils cost a minimum of 3 times as much as mineral fluid bases.

    These being said, I agree with sir OTEP that semi-synthetic oils are a lot better than mineral based ones. Choosing one over the other depends on several factors: money, operational environment of the vehicle (stop-go driving over long straight dirives), OEM specifications, lubricant properties, age of the vehicle and what kind of maintenance it undergoes.

  6. Join Date
    Sep 2005
    Posts
    17
    #26
    The best protection that you can give your engine is to use a reasonably good but inexpensive oil and change it every 3,500 kms. That would give you better protection that extended use of expensive synthetics.

    The usual 5T kms rule no longer holds in our driving environment becasue 1) the air is more polluted than it used to be thus making your oil dirtier sooner and 2) traffic conditions in MM cause the breakdown of the minerals sooner.

    You can say the 2nd reason is a good argument for synthetics but the pollution factor simply negates and even precludes the extended use of synthetics.

    Of course, if you have cash to burn and want to prolong your engine, synthetics every 5kms would be nice.

Page 3 of 3 FirstFirst 123
Semi-synthetic oils on diesel engines