johnlad said:
fully synthetic is intended for extended service intervals mainly for fleet operaters, and in my opinion 2x 3k oil change costing £11 for oil is better tan 1 x 7k oil change costing £30
Click to expand...

That is so wrong :(

Fully synth is in no way just intended for extended service intervals, it offers better protection, is more sheer stable, handles heat better, cleans better etc etc etc.

There are fully synths out there that are designed for extended drain but are denoted by a LL spec and used in BMWs etc.

I have tested fully synths in performance cars doing track days and the oil is still like new after 13k miles and Mobil have actually tested their Mobil1 to 60k miles so unless your engine has an issue like over fueling you will always be well within the capability of the oil if you follow the service recommendation. All this 2-3k oil changing is quite comical lol but the general response is 'better safe than sorry' which is fair enough if you enjoy doing things for no reason :)
 
+1^^^, i change the fully synth at 7-8K miles cos mine is tuned to stage 3, i tow a heavy boat, and often seing 900*C(some times peaks of 1000 too) on the EGT gauge when i floor it uphill... maybe i'm exagerating a bit but after the look of the rotor filter i've always been pleased that i changed it, as i can afford i like to be better safe than sorry and not let some broken oil in it:)
 
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sierrafery said:
+1^^^, i change the fully synth at 7-8K miles cos mine is tuned to stage 3, i tow a heavy boat, and often seing 900*C(some times peaks of 1000 too) on the EGT gauge when i floor it uphill... maybe i'm exagerating a bit but after the look of the rotor filter i've always been pleased that i changed it, as i can afford i like to be better safe than sorry and not let some broken oil in it:)
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id be starting to worry if your egt is approaching 1000*c as you risk melting a piston above 700*c
 
i'm worried too:eek: , though it's only short peaks if i floor it uphill with the boat attached... the average EGT is around 750 so good enough, i wasn't extremely stressed though cos it's supposed to bear that according to RAVE
RAVE - ENGINE MANAGEMENT SYSTEM - TD5 said:
The turbocharger is exposed to extremely high operating temperatures (up to 1,000 °C (1832 °F)) because of the hot
exhaust gases and the high speed revolution of the turbine (up to 150,000 rev/min). In order to resist wear of the
turbine bearings a flow of lubrication oil is supplied from the engine lubrication system to keep the bearings cool. Oil
is supplied from a tapping at the front of the full-flow filter adaptor housing via a metal pipe with banjo connections.
Oil is returned to the sump via a metal pipe which connects to the cylinder block at a port below the turbocharger
assembly.
Click to expand...

...and the bolded part is ONE of the reasons to use fully synth oil cos IMO a semi synth will suffer instant thermal breakdown there while the fully synth can go through with less damage
 
sierrafery said:
i'm worried too:eek: , though it's only short peaks if i floor it uphill with the boat attached... the average EGT is around 750 so good enough, i wasn't extremely stressed though cos it's supposed to bear that according to RAVE


...and the bolded part is ONE of the reasons to use fully synth oil cos IMO a semi synth will suffer instant thermal breakdown there while the fully synth can go through with less damage
Click to expand...

i hear what your saying, but a b3/b4 semi synthetic, must reach the same spec as a b3/b4 fully synthetic,
the only difference is as far as I know is the fully synthetic stays in grade for a longer period of time, hence why its used on long drain service intervals,
 
johnlad said:
i hear what your saying, but a b3/b4 semi synthetic, must reach the same spec as a b3/b4 fully synthetic,
the only difference is as far as I know is the fully synthetic stays in grade for a longer period of time, hence why its used on long drain service intervals,
Click to expand...

The difference is that some oils just meet the standards, others exceed them and some exceed them considerably.
 
20 ltr triple qx 5w 30 semi synthetic acea b1 api cf £39.00 delivered on ebay.
same oil that euro car parts sell only cheaper.
I bought 20 ltr 10w 40 for my tdi .works out less than £2.00 per litre :)
 
johnlad said:
i hear what your saying, but a b3/b4 semi synthetic, must reach the same spec as a b3/b4 fully synthetic,
the only difference is as far as I know is the fully synthetic stays in grade for a longer period of time, hence why its used on long drain service intervals,
Click to expand...

ACEA is a generic CLASIFICATION, Those A3, B3, B4, etc SPECIFICATIONS are not 100% connected to the oil's TYPICAL PROPERTIES and behaviour(which IMO is the most important),

we can have a friendly polemic on this no probs, just that i'll not go deep into theory cos it can be boring, to make a point i searched two oils with the same specs, just for example, but this is valid for any specs, so both oils from the links are ACEA A3 / B3 / B4 - API SL / CF , concentrate on theyr's TYPICAL PROPERTIES, to not be very hard see the Viscosity index(VI) and Density D) the comparison is for 5w40

1. fully synth VI=174, D=860 Mobil Super 3000 X2 5W-40

2. semi synth VI=168, D=856 http://www.gazpromneft-oil.com/clients/gpn.nsf/id/E57C60CD237BFD49C22579D10063F64B/$file/009_G-Energy%20Expert%20L%205W-30%205W-40%2010W-40%20eng.pdf

don't think that 4 - 6 units are not important in that area, but there are other differencies too which is a long story, in the end everybody' is free to treat his engine as he wants, i like to put in mine what i think it's the best for it not to save few quids and fill it with cheap sh*T :rolleyes:
 
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johnlad said:
i hear what your saying, but a b3/b4 semi synthetic, must reach the same spec as a b3/b4 fully synthetic,
the only difference is as far as I know is the fully synthetic stays in grade for a longer period of time, hence why its used on long drain service intervals,
Click to expand...

I have tested over a dozen different oils from Halfords own brand upto Ester based oils like Silkolene Pro S that all meet the same specs but their make up and additive pack contents are totally different. I have then tested these same oils again at different mileages and usages from 2k-15k miles and you discover which oils are sheer stable, which ones are no longer protecting how they should and which ones are still like new. The ACEA specs are a very basic set of requirements in order to classify an oil and it certainly doesnt mean all oils that meet the same spec are the same.
 
Tuskenraider said:
I have tested over a dozen different oils from Halfords own brand upto Ester based oils like Silkolene Pro S that all meet the same specs but their make up and additive pack contents are totally different. I have then tested these same oils again at different mileages and usages from 2k-15k miles and you discover which oils are sheer stable, which ones are no longer protecting how they should and which ones are still like new. The ACEA specs are a very basic set of requirements in order to classify an oil and it certainly doesn't mean all oils that meet the same spec are the same.
Click to expand...

You sound exactly the right guy to give us a mini master-class in engine oils then.

What characteristics should we be looking for, in an oil for the TD5 engine?

Is it the viscosity at -40 and 100°c? Measured in what units - cSt? Should we be saying that bigger numbers are better?

Is it the viscocity index? Is 174 better than for example 160 and in what way?



Is it the level of Sulphated Ash Mass?


What elements of the oil specifications illustrate best the relative quality and suitability of the product for use in our TD5 engines - on a replacement cycle of for example 10,000mls?

I would really like to understand this subject better.

Have just e-mailed Comma Oils to ask them to explain why they believe their PD Plus 5w-40oil (specifically for EUI engines) is different and better than the Xtec 5w-30 which they on their website recommend for our TD5's???????

Cheers
Dave
 

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I am not a chemist and not an 'expert' but i do know more than your average Joe as collating oil data from test engines was part of my job for a few years. i have worked with experts though so have picked up the main info that helps me understand oils more :)

To be fair its near impossible just looking at the bottle in the shop which is why most people think 'all oils are the same' My main advice is stick with the well known brands where you can, there is always a bargain out there somewhere and get the right grade. The expensive stuff is 99% of the time unnecessary for your average motor, yes its better but you can get oil half the price that is still up to the job.

Viscosity is measured in Centistokes, the higher the number the thicker it is. The ratings cover a band so an oil that is the top of the 30 grade isnt much thinner than one at the bottom of the 40 grade.

The quality of the oil is hard to establish even by looking at the MDS as you need to test it to get the level of additive pack and the TBN & TAN. TBN is an oils base number and generally starts between 7 &10 (the higher the better) TAN is the acidic value in the oil and starts low (1-2) as you use the oil the TBN goes down and the TAN goes up (exhaust gases are acidic) It is a general rule of thumb it is best to change the oil when these number are just about to cross over.

I will dig out some data and explain what it means :)
 
Tuskenraider said:
I am not a chemist and not an 'expert' but i do know more than your average Joe as collating oil data from test engines was part of my job for a few years. i have worked with experts though so have picked up the main info that helps me understand oils more :)

To be fair its near impossible just looking at the bottle in the shop which is why most people think 'all oils are the same' My main advice is stick with the well known brands where you can, there is always a bargain out there somewhere and get the right grade. The expensive stuff is 99% of the time unnecessary for your average motor, yes its better but you can get oil half the price that is still up to the job.

Viscosity is measured in Centistokes, the higher the number the thicker it is. The ratings cover a band so an oil that is the top of the 30 grade isnt much thinner than one at the bottom of the 40 grade.

The quality of the oil is hard to establish even by looking at the MDS as you need to test it to get the level of additive pack and the TBN & TAN. TBN is an oils base number and generally starts between 7 &10 (the higher the better) TAN is the acidic value in the oil and starts low (1-2) as you use the oil the TBN goes down and the TAN goes up (exhaust gases are acidic) It is a general rule of thumb it is best to change the oil when these number are just about to cross over.

I will dig out some data and explain what it means :)
Click to expand...

bloody `ell yer lost me but please carry on.
 
Yer thats the problem, its very technical so you have to either go into to it fully or not bother :D Its complex stuff and most of it i still dont get lol.

Right have a look at this :D

attachment.php


These are mostly top end oils as i was doing tests on oils used on Nissan 200sxs. For those who dont know they have 1.8 or 2.0 turbo charged petrol engines. I do have diesel data for the Puma engine so might stick that up later as its probably more relevant.

So hope you all know your periodic table :D

The first lot of numbers (mainly single and double digits) are mainly metals and this is where you look to see if your engine is knackered. High sodium values suggest head gasket (coolant has sodium in) and high Silicon could come from dirt (so check your air filter) or from fresh sealer if used recently. Some oils use Moly as a friction modifyer so a high value will reflect this (Motul 20w60). Moving on we get to the additive pack, Ca, B & S are detergents, P & Zn are Antiwear agents and Mg a corrosion inhibitor, the higher number the better.

KV40 & 100 are your viscosities at 40 & 100C, if these are much less on the used oil than the new then that could be due to the oil sheering or something like fuel dilution.

Soot is self explanatory and a problem with diesel engines, i have seen test engines where you could spoon the oil out the sump :doh: anything above 3% is getting high.

And then on the end you can see the TBN and TAN numbers.


Enjoy :D
 

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Oil

Well I ran an old 1970s car on the wrong oil changes for a couple of years. Read services every 10,000, missed changes every 5000.

However I was keeping it well maintained and changed the oil before the 10,000 miles. So was a change every 9 months or so. And it came out OK.

No appreciable wear after 50,000 miles of thrashing it, with rally camshaft and raised compression ratio. Running nearly double the distance of oil changes. I did find my mistake and shortened them but not too much as the oil was still nice.

Esso 20/50 oil.
 
This question about oils specifically for TD5 engines kicked off for me when Fery mentioned this Comma oil which proclaims to be specifically for EUI engines such as the TD5.

I have asked Comma to explain what characteristic it is in their oil which supports their claim that their oil has some kind of advantage, for this type of engine and I await their reply.

In the table I posted there were significant differences between the 2 sets of data, the first set for Xtec 5w-30 (their recommended oil for our engines) and the 2nd set for for the 'special' Pompe Duse engines (like ours!!!)

The question in my mind is, out of the mountains of data one can collect these days via the 'net; which are the key characteristics for judging one oil over another?

Data is not information in my book.
 
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