Oils for diesel engines

This is a subject I find full of interest and one thats a changing subject matter as the years go by,it is of course closely connected to the oil filters and good engine managment and maintainace but all stuff we can handle ourselves with nothing more than dirty hands,plus some oil in the bilges if we forget to use a drop tray.

All top brand oils are acceptable in principal but they are not all the same and should not be mixed if you have the choice,buying to price is not the way to choose but Castrol Oils discount offer on a free 500mm was acceptable to me when I bought this diesel grade oil.

Diesel grade,whats all this about,did you know there was a choice,whats the difference?

The first time I ever noticed was on a new engines oil grade instructions and the fact that normal oils must be changed with the oil filter every 50 hours or once a year but and its a big but,if we use diesel grade oils we can go to 100 hours each year,thats an extra 100% in engine hours!

This subject is complex and I am not going to say much more right now but use diesel oils,and ensure its the right grade for your engine,this Castrol oil is suitable for older engines,it will have more additives in it but some more modern engines will need a less added to oil as they run to closer tollerances,thats my understanding.

This is part two of a paper yacht designer Dudley Dix sent me recently,its about oils and the additives that became common in them over time,after WW2 they added more and more,so the engines were designed around the oils of that time.

Now we see a need for super clean burn engines,so the oils have less and less aditives,should we use so called modern oils we may not be using the correct grades at all.It seems that older engines say mid sixties to eighties may have had oils with ZDDP additives as high a 1500 parts per million,thats high by todays standards?

Note,this is from a USA based Lotus Europa forum,if I can find the first one I will post it soon.

I'd like to re-itterate my concern over 10W30. It's one of the five

mandated low ZDDP oil grades under API SL, SM and SN. If you use an old
API grade like SH or SJ, or if you buy a specific high performance brand
like Redline, or certain street-capable Racing Oils, then 10W30 may have
adequate ZDDP. But if you're just walking up to the oil shelf at the
parts store and grabbing a quart of 10W30, the chances are high that it
will contain only 600-850ppm if it's SM, and less if it's SN (700ppm ?).
Don't put that panty-waist oil in your Europa.

More on this and running tempratures in the next related engine blog to follow.

R McB