The Fordson Tractor Pages Forum

Hi all , ihave tried googling this but to no avail , what does the HD mean on a
30 oil. ie sae 30HD / sae 30 .. some say heavey duty some say high detergant
others heavey diesel , others just a selling point for oil companies, so does it matter or not
whe buying oil for our dextas.

Hi
I googled "oil high detergent" and got a whole raft of Q&A's.
There was a previous thread on this topic.
I (IMHO) feel that if you are adding oil to top up/replace on an existing engine that has wear and residue build up then try and match it to what has been used before.
A High Detergent oil will clean out deposits in an old engine which may then accellerate wear, bearing or seal failure (may well be whats keeping your piston rings holding compression).
If starting with a new/Recon engine then maybe a detergent oil from scratch is the way to go.
I should think that in a dextas past history it may well have had a HD oil added/top up at some time.
I remember in the 60's/70's the British Army switched their standard engine oil (OM [Oil Mineral}) to OMD (Oil Mineral Derergent) and suffered a fleet wide series of engine failures (1,000's) due to the new detergent cleaning out deposits etc from some quite old engines.
For a long but enlightening read try http://www.calsci.com/motorcycleinfo/Oils1.html, which seems to cover every base on oil questions.

Jerry
Bath
UK

i know when you start reading oil the lists and ? an ans can do your head in .Everyone has their own
theory, but i have yet to find out what is the differance between 30w hd and 30w , if there is no differance
then sae30 oil should be alright for the dexta engine,

Just a follow up , i contacted castrol tec/ dept asking did they know the differance, their answer
was , the hd normally means heavy duty , for commerical diesel vans etc, as in their tection 30 monograde oil,
an the sae 30 or xl 30 for lighter engines, so still not really a difinite answer