Is the reason that more people dont use diesel oils because they dont offer them in all the same weights as Synthetic? Im thinking now that when I switch to Synthetic in my dads '03 4.0L V6 4runner, that I should use D1 5w-40 instead of M1 SS 5w30. How long can I go on each one? With a Toyota Filter?
using diesel engine oils in gas engines, good or bad?
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I have just assumed that for a older engine with blowby a disel rated/SL oil would be good, since the soot control of the HD disel oil would help keep the blowby products in suspension and the extra cleaning would be good for an older engine. In others words, it could not hurt and might even help.
Is this wrong?
Is this wrong?
HD diesel engines with roller lifters have fairly low frictional losses in the valvetrain to begin with, so adding a friction modifier like moly doesn't provide the same benefits in does in a gas engine, particularly one with DOHC and direct acting cam lobes/valve lifters. Moly is also added to help gas engine oils pass the "energy conserving" rating, which is not a requirement for CI-4 rated diesel oils.
A more effective scheme for reducing frictional losses in HD diesel engines is to use a low viscosity, 5w30 or 5w-40 synthetic. This will reduce frictional losses between the piston rings/cylinder walls and in the main and rod bearings, which operate under hydrodynamic lubrication.
This is one of the main reasons why you don't see Mobil adding moly to Delvac 1, 5w-40. It would provide little additional benefit to the additive chemistry they are currently using ....
TooSlick
A more effective scheme for reducing frictional losses in HD diesel engines is to use a low viscosity, 5w30 or 5w-40 synthetic. This will reduce frictional losses between the piston rings/cylinder walls and in the main and rod bearings, which operate under hydrodynamic lubrication.
This is one of the main reasons why you don't see Mobil adding moly to Delvac 1, 5w-40. It would provide little additional benefit to the additive chemistry they are currently using ....
TooSlick
MolaKule
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Here's whay I think they don't use moly in Delvac 1.
From my research, Moly is an excellent friction modifier at low temps and an excellent AW additive at high temps and contact pressures.
Moly is a bit more expensive than Boron, or Potassium or Sodium Borate esters. The borate esters act as friction modifiers, anti-wear, and detergent additives. Now since the Boron Esters have been introduced by Vanderbuilt and others and has a lower cost than does MoTDC, why use a separate friction modifier that is really not needed when a muilifunctional additive of lower cost can do the same job?
For gas engine oil, one wants an additive package that has both AW and FM's to protect the direct tappet systems and cam lobes of DOHC auto engines.
[ April 06, 2003, 02:47 PM: Message edited by: MolaKule ]
From my research, Moly is an excellent friction modifier at low temps and an excellent AW additive at high temps and contact pressures.
Moly is a bit more expensive than Boron, or Potassium or Sodium Borate esters. The borate esters act as friction modifiers, anti-wear, and detergent additives. Now since the Boron Esters have been introduced by Vanderbuilt and others and has a lower cost than does MoTDC, why use a separate friction modifier that is really not needed when a muilifunctional additive of lower cost can do the same job?
For gas engine oil, one wants an additive package that has both AW and FM's to protect the direct tappet systems and cam lobes of DOHC auto engines.
[ April 06, 2003, 02:47 PM: Message edited by: MolaKule ]
Sorry TS, I don't agree with you on your assesment of moly not helping a diesel engine. I have to agree with Mola on the fact cost is the biggest thing when it comes to most oils using moly. If memory serves, I do believe that Mobil does have a synth diesel oil(15w40) that does have moly in it. I'll have to look at some of my oil analysis. Will get back later on that.
Molakule, could you amplify on that, please? On the one hand, I think I understand you to say that the current additive chemistry in D1 is functionally equivalent to moly? On the other, you seem to imply that gas engines should have an additive package that is something different from what we find in D1. I'm not taking exception. I just am not following you here.
YZF150,
I think that molakule and I agree on this ...as I mentioned there are greater frictional losses in the valvetrains of multivalve gas engines. So an additional friction modifier can be useful, although boron performs much the same function.
TS
I think that molakule and I agree on this ...as I mentioned there are greater frictional losses in the valvetrains of multivalve gas engines. So an additional friction modifier can be useful, although boron performs much the same function.
TS
Guys probably all automotive diesel engines" big truck engines" are 4 valve per cyl.and have been for years and years. That is why the oils have lots of additive in ppms to prevent wear in the valve train where the highest stress is in an engine. That is the reason Amsoil shows good wear numbers it's the high additives.
[ April 08, 2003, 11:04 PM: Message edited by: Steve S ]
[ April 08, 2003, 11:04 PM: Message edited by: Steve S ]
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