Any particular brand of diesel engine oil recommended?

ed4ferrets · Post by **ed4ferrets** » Sat May 03, 2008 10:43 pm

I've just put some Quantum (or somesuch) VW recommended diesel oil in my TZD but would like to replace with semi synthetic at earliest opportunity.

Which brand is recommended by those in the know please... under £20 preferred

, I don't hammer the motor if that is of relevance.

MULLEY · Post by **MULLEY** » Sat May 03, 2008 11:24 pm

Forgot the name that i use, but its available in GSF, i use semi-synthetic 10w40, costs under £12 for 5 litres....

Post by **docchevron** » Mon May 05, 2008 1:58 am

That'll be quartz 7000 10/40 then!
I use it in the valver, but in the diesel I use quartz 5000. I dump it every 3K miles so there's no point in me using semi in it really..

Vanny · Post by **Vanny** » Mon May 05, 2008 10:32 am

Chevron do some good diesel oil for turbo's, they sell through Costco and a 25 litre barrel is about £30

I prefer Castrol GTD for a XUD turbo diesel as it makes a noticeable difference to the engine, but it works out nearly £5 a litre so not so good on cost if you throw it out after 6000 miles!

Every now and again Tesco and ASDA screw up and put there own brand oil out for about £2 for 5litres. Its a big name brand oil inside (i forget which) though i wouldn't run it for long, it makes a nice cheap flushing oil!

And dont forget to add diesel to your old oil to thin it and flush it out better.

ed4ferrets · Post by **ed4ferrets** » Tue May 06, 2008 9:44 pm

docchevron1472 wrote:That'll be quartz 7000 10/40 then!
I use it in the valver, but in the diesel I use quartz 5000. I dump it every 3K miles so there's no point in me using semi in it really..

Where do you get this evil brew from doc? So semi is good for somewhat extended use then..... 8 to 10k miles maybe?
Edit: Quartz is a Total product is it not, so obviously readily available!

Vanny wrote:And dont forget to add diesel to your old oil to thin it and flush it out better

For clarity I was wondering what quantity of diesel to add for a good flush and how long to run it (presumably till engine is warm enough?).

MULLEY · Post by **MULLEY** » Wed May 07, 2008 1:02 am

The brand i've been using is FUCHS, german i believe....

Vanny · Post by **Vanny** » Wed May 07, 2008 9:12 am

about a litre of diesel, run the engine on idle till the cooling fans come on. Extends the time it takes do a service but makes a huge difference. Diesel is the main constituent of most engine oil flushes. though its starting to look like the snegine flush cans are cheaper than diesel

Post by **docchevron** » Wed May 07, 2008 2:56 pm

Quartz 5000 and 7000 are both Total oils and are available pretty much everywhere, including Total filling stations!

I always use Forte Engine Flush (which is excellent), just add a bottle to the oil, run till the fans come in, dump oil, job done, clean enough inside to eat your dinner off (if thats what you'd want to eat your dinner off in the absense of plates and what not)..

I have no idea how long the service intervals are TBH, I never leave the oil in that long, both the diesel and the valver get fresh oil and filters every 3K miles.

ed4ferrets · Post by **ed4ferrets** » Tue May 13, 2008 9:15 am

Vanny wrote:about a litre of diesel, run the engine on idle till the cooling fans come on.

Pedant mode ON: ... does this require draining some of the oil before adding diesel or can the engine be run at idle whilst 'overfull' until fan comes on?

DLM · Post by **DLM** » Tue May 13, 2008 1:12 pm

Good question, Ed - I await the reply with bated breath.

Myself, I've several times used a Texaco branded 15w/40 mineral oil which Asda knock out at £8 to £9, when not using anything else. My local GS&Fs have always offered me the Quantum oil when I asked for anything golden and lubricating, and very rarely had the Total in stock. I've never put a synthetic or semi-synthetic in a BX diesel or petrol, largely because

(a) I'm probably too much of a skinflint - and I'm very skeptical about the motives of the oil industry.
(b) The XU/XUD is an engine of relatively old design
(c) I don't run a 16v - where top-quality oil is essential at all times
(d) I saw many forum postings where people had put synthetics and semi-synthetics into XU/XUD engines and provoked blue smoke because it was too slippery. Admittedly some of these were people who'd swallowed the snake-charming myths of the PR side of the Oil industry absolutely whole and put in inappropriate grades. The Aussiefrogs forum will no doubt have some trenchant postings on the subject, if you're looking for historical references.

Post by **docchevron** » Tue May 13, 2008 1:48 pm

Over filled by a litre on idel will do no damage.

Dont go forgetting you've put it in and drive off to the andes though!

Semi isn't the law with oils for the 16v, but it makes very good sense to use semi.

XUD's will run a semi with no problem, as long as it's not pi$$water like 0-30 or some crap like they use in Ford engines (how tight must their tolerances be!?)
but I never quite saw the point of using a semi oil in a diesel engine.
The oil gets contaminated quite quickley, so regular changes will always be better for a diesel, despite the latest generation of diesels that have 12,000 mile intervals (no way would I leave oil in any engine that long).
So since semi doesn't break down as fast as straight mineral oils it's a waste of cash to use semi in a diesel (unless you get the oil for free!).

MULLEY · Post by **MULLEY** » Tue May 13, 2008 11:20 pm

The only reason i've used semi on the txd was it was less than a quid more expensive than the mineral oil.

Also thought that because it was better quality it would lubricate better??? & also help the mpg as well?? oh & be more resistant to using veg oil in the car, apparently it does get into the oil system which isnt ideal....

These could of course be total misconceptions on my part, i just havent managed to find cheap mineral oil....

AndersDK · Post by **AndersDK** » Wed May 14, 2008 6:37 pm

Go by the factory recommandation and use viscosity 10W40 - which is way more than adequate in all parts of UK all year - and in DK too.

Wether you choose semisynth or mineral is no real concern like Doc says.

Instead spend your money on the highest alphabetic API rating code found on the bottle, as this is directly a measure of the oils quality and longevity.

DLM · Post by **DLM** » Thu May 15, 2008 10:54 am

Absolutely, Anders - API codes are a much better guide to what's in the bottle and its suitability for your engine: in fact, often much a much better guide than the price, branding and marketing of the product.

MULLEY · Post by **MULLEY** » Thu May 15, 2008 5:28 pm

API Codes, i've heard of them but dont know what they mean.

Anychance someone could give me & others a run through of what to look for please?

Thanks