Sunday, Sep 01, 2013 at 11:17
Mate Valvoline has never been the best oil......ever...even more so now it is BPs budjet brand.
British Petrolium ( BP) own both Castrol and Valvoline...interesting that BP no longer market some of the very good oils that came under the BP brand..
AND in the independent tests conducted in the trucking industry, neither Castrol nor Valvoline figure in the top bracket.
What we are hearing is the old, "brand and type of oil doesn't matter line"...oh the alternative and cheaper brands love to push that one.
The fact is..OILS AIN'T OILS Sol.
In the very competitive, commercial, diesel spec market the top 3 oil companies dominate and there is very little to seperate them.
This is a very large volume market and the smaller independent oil companies like Penrite simply can't compete on a price for spec basis.
There are enough of us that have had significant improvements in our vehicles by switching to one of the three top diesel spec oils to prove that it is a fact.
Oil filtration is not 10 times more important than anything......that is a line that has been pushed by certain aftermarket oil filter sellers.
Filtration is important, but if the oil will not suspend the solids and deliver them to the filter, the filter is far less effective.
In diesels particularly the small pre common rail engines, one of the most significant issues is the ability of the oil to suspend soot.
Another is the ability of the oil to clean in behind the rings..where soot accumulates....accumulation of soot behind the rings can result in loss of compression and blowby.
Another issue is the quality of the base oil and a minimum of viscosity modifiers used....cheaper base oil requires more viscosity modifiers to meet spec.
As viscosity modifiers and other additives break down they form sludge......this sludge blocks the PCV circuit and other parts of the engine resulting in oil being deposited in the air cleaner.
As many of us have found, running one of the top 3 diesel spec oils in the correct grade solves or reduces many niggling problems.
Smoke on start up, contamination of air filters, loss of compression and so on.
On another
forum I attend, someone comes on at least once a month with a problem with a Nissan or Toyota using oil and blowing smoke after they have changed the oil with some fancy hype marketed oil.
One very common problem is people thinking thicker is better and running 20w50 or thicker oils where 15w40 is speced....some of the small diesels have carefully calcuated drain rates from the head.
The aim is to retain sufficient oil in the rocker compartment for proper lubrication.
If however a thicker than speced oil is used the head drains slower the oil level in the rocker compartment rises and the valve seals ( particularly slightly worn ones) allow a lot more oil to pass resulting in smoke.
time after time the advice is the same, and so is the result.
Now I have mentioned the three commonly available JASO DH1 oils that figure in the top of their group....and oils in that market are so very close in performance.
Castrol RX super does not rate as high as the above 3, but it is not shabby.
My brother until recently ran an MQ diesel that he owned from new it did a lot of very hard
miles.
It has had two full engine rebuilds, prior to the first rebuild he was using a fancy upmarket oil.....his long time friend rebuilt the engine both times.....first time the quantity of sluge in the engine was conspicuous......now big brother is pedantic with vehicle servicing and always changes oil on time or early.
The engine rebuilder put him onto RX super over 20 years ago when it was a very competitive oil.
The second rebuild the interiour of the engine was
bright & clean.
The good diesel spec oils (RX super included) have very strong additive packages and will run in some engines for 50 000Km and still be
well within spec.
Oils aint oils.
And price is not always a good indicator of quality.
cheers
FollowupID:
797092