Oil change

[ANDY 545]

I am trying to find the best routine for oil changes and type of oil, I would appreciate any help with this.
I bought my cdt 12 months ago totally standard no mods, my mileage is approx 8000 a year. Driving is towing a caravan in the april to august then mainly short stuff through the rest sometimes not even getting fully warmed up, my normal routine is to change it every 6 months with a filter an 10w/40 semi synthetic.
So would I be better going for a fully synthetic such as millers XFD 5w/40
or Halfords own 5w/40 fully synthetic every 12 months.
The car has covered 61000 miles and I intend to keep it indefinitely as its the business but you already know that:bowdown:

[GreyGhost]

0w 40 is the recommended fully synthetic I would not advise going against the manufacturers requirement.
Oil and filter change every 6 months for a vehicle doing 8K per annum is serious overkill but that is your choice. Modern oils and cars require change at yearly or 15K

[JohnDotCom]

Mobil 1 0w 40w is the Spot on Oil recommended and I would say with your mileage once a year oil change as said by GG is more than enough, it does take a lot for the diesel (Need to purchase 7 litres). Some stores sell this in 5 litre size now rather than the 4 litre size which 2 of is good for change and any top up during year.

[MartinW]

If it's semi- you're using, and this is normally cheaper than the full synthetic, then 6mthly may not be a bad thing if you do it yourself because you state that you sometimes don't even getthe car fully warmed up which can be more damaging than a long motorway run. Plus, yours being a diesel, I would stay away from the Mobil1 as it has a lower API C rating than the S rating, and is ideally suited to petrol engines, not diesel. Your diesel also has an Exhaust Gas Recirculating valve allowing unburnt fuel a second pass at being burnt, but this increases the soot loading on the oil (the very black stuff that discolours the oil, it is usually less than 1µm in size, that's a 1/1000th of a mm!

Cold running and lots of idling and lugging increases the strain on the oil, so in your case this will be greater than someone on motorway runs regularly. I'd look at what BMW use as some of their service intervals are quite long now by comparison for their diesel units, up to 2yrs, but your service indicator will also use an algorithm to assess your driving style and use and alter the interval accordingly.

Check what your handbook reccomends in the way of the ACEA or API rating, and also look for oils thathave these approvals on the can along with any OEM approvals. If you are keen to go with a long term ownership, then invest in a quality oil such as Millers and and do an annual oil change.

[JohnDotCom]

The Mobil 1 0-40w is stated in Facelift Manual & on car Label for use in the Diesel Models and Recommended by Rover & BMW.

[MartinW]

I wasn't aware it was also recommended for the diesel engines, John, but it has a lower rating in ACEA & API terms than for the petrol engines, as Mobil1 is designed primarily for petrol engines. The current highest rating for petrol engine oil is API SM, and for diesel the highest is API CL-4. Mobil1 is API SM/CF and the C (Commercial or aka Compression) rating is for diesel and that CF is at least 3 categories below the current highest rating. The current highest rating for C is based on the soot load problems that diesel engines suffer especially during Winter months, lack of proper warm-up, long periods of idling/lugging and with current EGR technology. The problem with soot is that it clusters to form larger abrasive particles and so soot load capability is very important, as is the Base Reserve which must counter the fuel dilution and consequential sulphuric acid build-up.

I am surprised at BMW/MG R recommending this for the diesel, but then I assume this may be to do with the engine not being the current one. My current can of Mobil1 shows approvals from various manufacturers inc. BMW. However, as with all these things, if you only plan to keep the car 3 years then use the recommended oils, but if you are planning a long term affair with the car, then go for the very best and I would certainly look at an oil with a higher API C rating than Mobil1 for a diesel. I'd also use a very low sulphur diesel if possible to minimise corrosive wear as in Andy's case where short journeys will result in condensation and fuel dilution that will create high levels of sulphuric acid.

[JohnDotCom]

Martin, Might be Misleading you slightly here unintentionally, been out to Garage to check what was put in, it is Mobil 1 0w-40w but it does say "Diesel" on bottom left of corner in Gold.
Presume something is added to this, been using it since Car new but only just noted the Diesel label otherwise container is Identical to what i presume is Petrol version (non labeled Diesel) which I also have for the Petrol Car now!

[MartinW]

John
I don't often look in Halfords at the diesel engine oils, and I had thought there might have been a specific diesel version but I wasn't sure. Would you do me a favour, please, could you tell me what API rating is on your container? It will be on the back side in fine print. I guess you will find it is a much higher API C rating, possibly CI-4 (4 for 4 stroke) whilst the S rating will be lower, possibly SG or SH.

But a good point, all CDTi owners should look to see that the Mobil1 oil 0W40 is teh diesel spec version and not the petrol spec version.

[ANDY 545]

Thanks for the feed back guys
The oil I currently use is one I bought wholesale in a 25 litre drum its called
EXOL SEMI-SYNTHETIC 10W/40, meeting API CH-4/SL, ACEA A3,B3,B4, thats whats written on the label. Now my car is a 52 plate 03 model and the hand book states Approved viscosity 10w/40 or 15w/40 meeting a minimum spec of ACEA A3,B3. So the current oil meets the basic requirements dont you agree,
which I am changing every 6 months. I think the advantage of doing what Iam
doing is to clear out all the pollutants out of the engine but would a fully synthetic changed every 12 months be better for the cold running /short trips etc. I suppose what Iam getting at is which is the most damaging for my car and which would give me long term minimum wear and build up deposits in the engine.
Regards Andy

[MartinW]

Andy
My choice would be the full synthetic for the 12 mnth period so long as you are below the max miles for this period.

Here's why:
Firstly, ACEA and API have criteria against which an oil submitted for approval is tested. If the oil meets OR exceeds the minimum criteria then it gets approval. It costs a lot of money to submit an oil for testing so you can be assured that the oil does meet the minimum criteria, but in some cases it may only just meet the minimum criteria. In other cases it so far exceeds the minimum criteria that it can actually meet the next level of rating when that is introduced at a later date. BUT it is difficult to tell which these oils are that are better, however, Mobil1 does have a good reputation in the industry for domestic vehicle use. By the way, the criteria, in the case of diesel and petrol oils, will include tests to determine wear levels on the test engines (usually an engine that is representative of current design technology) as well as various oil health factors.

Now, as to why a synthetic is better than a semi. Firstly frequent oil changes can lead to contamination. Certainly in the past, the build up of contamination from fuel dilution and condensation and the formation of acids was such that it was deemed necessary to regularly replace the oil. That has changed with modern electronic control systems and better machining leading to tighter clearances, plus cleaner fuels. Now the problem is that new oil is not necessarily clean oil and does have some solid particulate. the act of opening the engine and draining oil along with refilling can add more contamination. Therefore the industry is moving to longer oil change intervals and the oil companies have risen to the challenge with longer service life oils, even, in some cases, sealed for life systems on gearboxes etc.

A semi-synthetic is a blend of mineral and syntehtic base stocks of oil, and offers the pricing of Mineral with the advantages of synthetic. But there is no legislation as to the minimum blend ratios so some will be a majority mineral blend formulated down to a price rather than up to a quality.

Syhtehtic base stocks offer a number of advantages and which is why it is worth using these. The main advantage is longer service life with less damage caused by heat from the combustion process. The second is a lower deposit forming tendency meaning that surfaces stay clean and fresh, and in fact it has a naturally high detergency level that helps remove deposits already formed. The third is a lower sludge forming tendency. The fourth is more lubricity and consequently less fluid friction and a very small gain in fuel efficiency. And lastly, they have a low volatility and so less oil gets burnt off on extended runs meaning less top ups required.

And that's why I say go for a full synthetic over 12 mths.

One caveat, if you can afford to do this, as you have run on a semi, then change the oil to a full synthetic followed by a reapeat change within 500 miles to clear out the deposits already formed which can block the filter on much higher mileage, older engines. However, as yours is a low mileage 3 year old car, you should be ok just doing the change.

[JohnDotCom]

John
I don't often look in Halfords at the diesel engine oils, and I had thought there might have been a specific diesel version but I wasn't sure. Would you do me a favour, please, could you tell me what API rating is on your container? It will be on the back side in fine print. I guess you will find it is a much higher API C rating, possibly CI-4 (4 for 4 stroke) whilst the S rating will be lower, possibly SG or SH.

But a good point, all CDTi owners should look to see that the Mobil1 oil 0W40 is teh diesel spec version and not the petrol spec version.

Martin
Right gone through whole very Brief details printed on 5 litre container (same as the leaflet on 1 litre ones)Fully Synthetic and it gives IMHO very few clues the whole panel gives its recommended for all the Different Makers Cars under individual Codes (BMW, etc) then has the following statement: Meets or exceeds: AC, EA, AJ B3, B4 then API: SJ/SC/EC/SM/CF No numbers or other details stated and at £38 per container you would think better info other than suitable for all Modern Turbo Diesels engines without changing for 15000 miles. :confused:

[MartinW]

Thanks, John. I am a little surprised at the quoted API specs, it still seems very low for a modern diesel. In fact the numbers look very similar to those quoted on my petrol version of the 0W40.
As to the information it is quite detailed for public consumption although most oil manufacturers will not share their additive formulations for obvious reasons, but one can download a technical data sheet and this can also be very useful for comparing oils giving information on the oil properties and performance tests done under ISO and ASTM criteria.

[ANDY 545]

Thanks everyone
The feedback has been very helpful and I think I will go down the fully synthetic route every 12 months, I feel this will be beneficial for the low winter temperatures and also aide with soot and other pollutants building up.
Theres also the point of the oil keeping its property's longer being man made.
I shall look at the various products for the API and ACEA ratings, one more thing in my search for information I read in couple of places that Mobil 1 Diesel was the same as Mobil 1 Petrol which surprised me but the specifications being talked about on here there may be something in it WHO KNOWS.
Regards Andy

[icogger]

Perhaps I can throw something into the mix - My cdt is coming up to oil change time - 1500 miles to go. It has had Mobil I in for nearly 15000 mls - oil on dipstick still looks like new and has not needed topping up since the last service. However due to the price of Mobil 1 I am thinking of taking car to National Tyres who will do an oil and filter change for £22.50 using Visco 3000 fully synthetic - anyone got any thoughts?

[JohnDotCom]

:welcome: Thats under half the price of Mobil 1 including the Filter, new Sump washer and Labour? Know nothing about the Oil or service there, but someone will be along shortly.

[icogger]

Thanks for the welcome - I've come over from MG-Rover org. forum.
Apparently National do a proper drain etc inc labour for that price if booked on-line, apparently the oil is BMW specced I believe.
Getting a bit late now so will check back tomorrow

[MartinW]

Sorry, been travelling!
OK, The national chains can buy in bulk so won't pay normal retail prices. But if you shop around I have managed to get Mobil1 at almost half Halford's price through trade.
Secondly, a little bit of a loss leader to see if they can flog you other parts and labour.
But there's no free lunch and whilst it may be BMW approved, as mentioned above some oils meet the requirements, some exceed it.
My personal opinion - these are complex cars and running one doesn't come cheap, therefore I would want to take mine to an approved service facility that will do a full service and that has T4 so they can identify any small issues before they get to be big issues or at least know the car well enough to know what's properly required of a service and how to spot possible issues.

[yp53]

An earlier post suggest that the EGR system is responsible (at least in part) for sooting-up of the oil. Does this mean that it might be a good idea to blank off the EGR system?

I hear different stories about pros and cons of cleaning the EGR valve system vs. blanking it off completely.

[bad-head-day]

However due to the price of Mobil 1 I am thinking of taking car to National Tyres who will do an oil and filter change for £22.50 using Visco 3000 fully synthetic - anyone got any thoughts?

That's a great price, I think they have a limit of 5l though - nope, I'm wrong it's 6l (I just checked).

http://www.national.co.uk/images/promo/winter_oil_filter.gif

[JohnDotCom]

That's a great price, I think they have a limit of 5l though - nope, I'm wrong it's 6l (I just checked).

http://www.national.co.uk/images/promo/winter_oil_filter.gif
No Good for the Diesel Engines then 6.4Litres!

[bad-head-day]

I'm sure it's worth giving them a call John :) The only thing I'd want to ensure is a drain from the sump plug rather than suction.

[icogger]

Sorry taken a while to get back! If you book on-line, booking is by Vehicle type and specifying diesel so there is no problem with the quantity of oil. The booking form that you print out and take with you identifies the vehicle and price.