diesel oil in gasoline engines

[SwampDweller]

Originally Posted by FordCapriDriver
Originally Posted by LeoStrop
Originally Posted by buster
Diesel oils turn low rpms and have higher levels of soot where as gas engines run higher rpms and have to deal more with acidic contamination from combustion by-products. More defoamants, AO's and acid neutralizing additives are needed. The friction modification is also sometimes different.

Diesel oil can also foam up pretty bad I. High rpms applications I believe. ??

Diesel engines with high load and low rpm may need an oil with a higher HT/HS and high PV coefficient where a aeration isn't much of a concern.


This was one of my doubts on running HDEO on my car. But since it's still stock and i hardly reach 5600 RPM, i decided to use it anyway. Maybe after i start doing some mods, should rethink my oil choice? But since people are having good results running HDEO on bikes and subarus, that should not be a problem.

I am also curious on the difference each oil has, to be able to deal with different fuels. Given that i use a diesel oil on my ethanol car....


Real world experience has shown HDEO does just fine in high revving engines, motorcycles for example.


I agree, HDEO has been and currently is used in outboard motor 4 strokes for MANY years at 4-6 thousand rpm all day. Also used in air cooled generators that sit at 3600 rpm day and night. I have and currently use it in both applications, along with a lot of others around here.

 

[demarpaint]

I see no problem with HDEO in a gasoline engine. Depending on the application it might be a better choice than a PCMO. EG: a hard working inboard boat engine. HDEO is in both of my brother's boats, [A Ford powered 351, the other an I-4 Iron Duke]. He has used HDEO for as far back as I can remember, well over 30 years if memory serves me correctly.

 

[buster]

If I'm not mistaken, diesel engines contain ZDDP bonded with primary alkyl groups which gives the oil more thermal stability and oxidative stability, but is less effective at wear protection. Gas oils contain ZDDP bonded with secondary alkyl groups for greater wear protection. They also contain more ashelss dispersants for soot. In a gas engine you want to combat acids. They also lack ani-foam additives. You can run them and they do have a good P-V coefficient, but I don't think it's an ideal choice.

 

[caprice_2nv]

I stick with Mobil 1 or whatever else is on sale (but lately preferring Mobil 1) in my 1976 350 Oldsmobile V8. It's a stock camshaft with well with valve springs so it isn't picky anyway but if I had a good upgraded camshaft ($ spent on my engine) I would spend the extra and get an oil that was meant for this application like the amsoil musclecar oil (whatever it was called) or redline.

I'm actually switching to high mileage Mobil 1 since my rear main seal and valve seals etc are now 12 years old and 100k miles since installing them in my 44 year old engine.

 

[Anduril]

I run it in my XTerra which sees plenty of towing and low speed off road use.