supermarket v shell/BP diesel

[skyship007]

Originally Posted by Fearone

Can you please tell me how you tested the oil? In what way was shell better than mobil etc?

I like to use a good quality oil but struggle to tell much difference tbh.

I use Blackstone Lab in the US (25 usd plus about 4 quid postage):
http://www.blackstone-labs.com/

Some engines are very sensitive to the amount of Zinc anti wear additive and a test of Castrol Edge TD 5w40 which is an Acea C3 oil designed for use with DPF diesels showed double the amount of Lead and Iron (Main bearings and general wear). I asked the R&D chaps at Castrol if their C3 oil was backwards compatible to an Acea A3/B4 spec and they said it was, BUT the figures tell all. (Same poor performance from a friend who using Mobil Turbo Diesel Truck 5w40 as I got).
The wear metal figures in the used oil for LM Synthoil 5w40 were very consistent and almost exactly the same as Shell Ultra 5w40.

I normally change oil every 10K km (Renault severe service interval), rather than the recommended 15K km, BUT I tried a 17K km run recently to see what the engine thought of that and was very surprised that although the Lead figure tracked the km, the Iron and Aluminium figures were lower in per km terms. That shows that the upper cylinder wear rates are lower with a longer service interval.

It's probably due to the fact a new oil filter is less efficient than a dirty one, although new oil also contains enough detergent additives to chew up the old anti wear layer faster than it is deposited for about the first 1K miles. So although I do a lot of short trips, the oil is in fact OK for the full service interval at present.

[Fearone]

Originally Posted by skyship007

I use Blackstone Lab in the US (25 usd plus about 4 quid postage):
http://www.blackstone-labs.com/

Some engines are very sensitive to the amount of Zinc anti wear additive and a test of Castrol Edge TD 5w40 which is an Acea C3 oil designed for use with DPF diesels showed double the amount of Lead and Iron (Main bearings and general wear). I asked the R&D chaps at Castrol if their C3 oil was backwards compatible to an Acea A3/B4 spec and they said it was, BUT the figures tell all. (Same poor performance from a friend who using Mobil Turbo Diesel Truck 5w40 as I got).
The wear metal figures in the used oil for LM Synthoil 5w40 were very consistent and almost exactly the same as Shell Ultra 5w40.

I normally change oil every 10K km (Renault severe service interval), rather than the recommended 15K km, BUT I tried a 17K km run recently to see what the engine thought of that and was very surprised that although the Lead figure tracked the km, the Iron and Aluminium figures were lower in per km terms. That shows that the upper cylinder wear rates are lower with a longer service interval.

It's probably due to the fact a new oil filter is less efficient than a dirty one, although new oil also contains enough detergent additives to chew up the old anti wear layer faster than it is deposited for about the first 1K miles. So although I do a lot of short trips, the oil is in fact OK for the full service interval at present.

Very informative, thanks.

I take it your engine (1.9td) was designed for A3 B4 oil? And the shell and lm oils you mentioned are A3 B4?
I assume C3 oil has less zink?

[Backhill1]

Originally Posted by skyship007

It does not relate to the temperature of the fuel, but more to the temperature of the injector and that depends mostly on cylinder head temperature. Very few engines have cylinders that all run at the same temperature and if you short trip with cheap fuel gum forms in the injector just after shutdown.

You could write a book about why most engines have a cold cylinder or two. Often it results from a combination of deposits in the cooling system and varnish forming around the top end of the oil system, so even when the designer gets it right, owners that fail to change the coolant (Or use tap water to top up), or do too long an oil change interval still cause long term issues with uneven CHT's.

I'm not sure about your point hence why I asked, all fuel injectors I have encountered use the fuel as there lubricant and for cooling. More so in common rail systems.
Engine Cooling systems have little or no impact on injectors unless a severe issue common to the engine is experienced even then a cylinder would pick up before an injector problem in most cases.

I have investigated high injector wear in many engines and its almost always been fuel quality related or engine faults causing high cylinder temperatures (Blocked aftercooler/intercooler, Low boost, timing) causing damage to the tips.

At the moment Dirt and the introduction of Biodiesel – or FAME (Fatty Acid Methyl Ester) causing contamination is the cause of almost all warranty claims we encounter on fuel systems. Modern systems just cannot take the dirt.

Most military equipment destined for dusty climates is presently being re-powered with mechanical engines from the 80's and 90's so they can cope.

One good thing to come out of modern diesel and the reduction in sulphur is the natural extension it has given us in oil change intervals.

[Bungo]

Originally Posted by Backhill1

Modern systems just cannot take the dirt.

Most military equipment destined for dusty climates is presently being re-powered with mechanical engines from the 80's and 90's so they can cope.

I'm intrigued as to what you mean by dirt ?
Also,are vehicle owners in dusty climates re-powering their vehicles ?

[skyship007]

Very informative, thanks.

I take it your engine (1.9td) was designed for A3 B4 oil? And the shell and lm oils you mentioned are A3 B4?
I assume C3 oil has less zink?

Yes, the pre DPF diesels use B4. Shell Ultra 5w40 and LM Synthoil 5w40 are both A3/B4 oils, although there is not much less Zinc in a C3 oil, which is why I thought they might be OK.
My EGR valve is probably stuck in (The spec of the 3 bolts was changed as some had sheared), so I'm not going to try and remove it until it blocks, which is why I did the C3 oil experiment to see if my 1.9TD objected to using a lower Zinc oil, which it sure did.

The recommended max OCI for my V40 is 20K km, but Castrol reduced that in the UK to 15K km (So the dealers can use cheaper Magnetec 10w40), although it appears from my results of a 17K km OCI that the 20K km figure is probably OK for most engines with good injectors and no HG leaks.

[skyship007]

Originally Posted by Bungo

I'm intrigued as to what you mean by dirt ?
Also,are vehicle owners in dusty climates re-powering their vehicles ?

Some APU and gen or AC sets used in the desert get a lot of problems and recon jet engines used to power them are very expensive. You can even get sand dust turn into glass inside the jet powered units if the intake filter gets holed.

Ultra fine dust can get past both air, fuel and oil filters very easily. It is the worst type of contamination in terms of the damage that results. It's possible to pre filter fuel, but nothing much can be done about dust getting past the rings and into the oil.

Oddly enough changing the air filter too often is bad news, but dumping the oil early in the desert is not. For a car turbo diesel 30 ppm of Silicon in the used oil is about the max, but you can get as much as 100 ppm of Iron without concern. Most I get is 8 ppm in a clean summer or 15 ppm in a dirty winter when they grit the roads a lot. That's with a 10K km run.
Most Volvo diesels sold in the mid East use a real good 15w40 oil and get it changed every 3K miles (Different warranty terms).

I would never use a non Volvo or Bosch fuel filter (Or push the limits in terms of when it blocks), as nearly half the injectors that get blown tips caused by bad fuel filtration. In a bad case it will trash the HP injection pump first.
I was surprised to see Bosh list incorrect installation as the third cause of common rail injectors failing.

[Bungo]

Sorry you've lost me there.
My question was to backhill1 re dirt in the fuel and dusty areas being a related problem for fuel systems in cars, not jet engines or engine oil.

[Rich850R]

We use shell V-power in our 850R, that said its been mapped to run on it, on the odd occasion I've been desperate and used supermarket fuel its ran like a total nail, in terms of idling and general performance

In our V70D5 we only used shell derv too. No other reason than the garage is 30 seconds down the road

[jonnyf90]

I use Shell as it's a minute drive from where I live. FuelSave is only 101.9p a litre, so only 2p more than Tesco or ASDA. As both of these supermarkets are across-city, it's pointless going there to save £1.50 a tank.

Having said that, with the wick on my little 13c turned up to 11psi +, it does have an occassional misfire if using 95RON on WOT.
I usually run Shell V Power Nitro+ (which I think is 98/99?). 109.9p a litre now. But usually returns 30mpg + on a long run as opposed to 27-28 with 95RON.

As said before, supermarket fuel still has to meet BS/EN standards so theoretically, should all be the same

Cheers
Jonny

[Backhill1]

Originally Posted by Bungo

I'm intrigued as to what you mean by dirt ?
Also,are vehicle owners in dusty climates re-powering their vehicles ?

Most of the issues from a non automotive industry is in the supply (45G drums / Jerry cans etc.) where the potential for the ingress is high.

Where a garage has an ISO agreed filtration system in the pump this is not so evident.

So this issue is not so evident in road cars.