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Ford Fiesta - oil for 1.4 tdci - fordfanindia

I would agree, asked and anwered many times. But there's a specific case, hence proceeding:

What i have:

1.4 tdci fiesta, Euro IV, done 35k km(22k miles), regularly serviced at Ford with 5w30 oil.

What i want:

oil other than 5w30, matching / bettering than Ford standards.


Why:

1) Standard 2 year warranty expired, so now can experiment.

2) what ford is pouring in is 5w30 semi-synthetic, and i feel it loses lubricating capacity with mileage- a 7k km done engine becomes noisy with ear-jarring engine top end noise.

3) 5w30 is not available outside- i mean outside ford garages.

What options i have:

Mobil Delvac MX: 15w40: mineral oil, can be changed every 5k.

Shell Helix HX7: 10W40. semi-synth.


I don't see ambient temperature below 20 degree celcius(68F) and summers see it crossing 40C(104F).

What i am wary about is i have read that this engine "must" use low SAE because thicker oil-crude buildup-turbo failure etc.

So which oil can i use?

Thanks for reading this patiently.

Edited by fordfanindia on 26/06/2014 at 15:00

Ford Fiesta - oil for 1.4 tdci - Manatee

If you feel that the oil is losing its virtue in the distance run between services, one option would be to change it more frequently.

Alternatively, use a better quality (fully synthetic longlife) oil that is recommended for the engine - e.g.

www.millersoils.co.uk/automotive/tds-automotive.as...r

or

www.millersoils.co.uk/automotive/tds-automotive.as...r

but if I understand you correctly, then such oils are not available to you?

I think I can see your logic here - the 'W' rating is not really an issue with a minimum ambient temperature of 20C, and why not use a 40 weight oil? Neverthless, you have to consider the special requirements imposed by the turbo, hydraulic tappets and presumably DPF.

I'd be very loath to use an unapproved oil - your handbook should say which oils can be used for various temperature ranges - is that no help at all?

Ford Fiesta - oil for 1.4 tdci - jc2

Look at his name-I wondered till I saw it-suitable oil is available at Halfords-let alone elsewhere.

Ford Fiesta - oil for 1.4 tdci - KenC

If you are in the UK,why not try eurocarparts & input your car registration number, you will be given a large choice of suitable oils and can choose the type that you can afford.

I buy Ford Spec Oil at Eurocarparts suitable for zeetec engine 5/30w WITH a free oil filter for £13., the trick is to wait until they have a discount ( which is very frequent) order the oil online, get a reference number then pick it up. note you always get the best price that way. I think if you spend a minimum amount eg £20 they may even deliver it free.

My wifes old Fiesta gets a yearly oil change even though the yearly mileage is very low eg only 2000 miles.

Ford Fiesta - oil for 1.4 tdci - Manatee

Let alone the OP's handle, if he/she never sees an ambient temp lower than 20C then I don't think Halfords or ECP are options :)

Ford Fiesta - oil for 1.4 tdci - fordfanindia

Ah i should i have mentioned that i am from South of India- the true tropics where the seasons are hot, hotter and the hottest and that would have saved a few people their typing times.

Yes, they don't sell 5w30 Ford spec oil outside; hence i asked about other grade.

But i called up a ford garage and it looks like Ford spec semi-synth is cheaper than the 2 oils i mentioned; so looks like i have to bear with a grin the visit to ford guys.

PS: unlike UK, here in India we don't get spares sold across the counter; and that's why the spurious parts from the east(read=China, Korea) arrive.

Ford Fiesta - oil for 1.4 tdci - MrEckerslikefromRamsbottom

Up to 2006, the Fiesta 1.4 Tdci didn't have a DPF, so there was quite a wide choice of oils available. The handbook states that a 5w/40 can be used in hotter climates, but as my 2006 Fiesta has done over 180K miles, I have opted to use 5W/40 fully-synthetic oil all year, though I sometime splash out on Mobil 1 0W/40 for a cold winter. Are 5W/40 turbo-diesel oils as difficult to find there as 5W/30?Is there a diesel particulate filter which requires a 'special' oil?

We don't know anything about hot weather over here in Ramsbottom! If it's that hot over there and 5W/40 is hard to come by, then I see nothing wrong with using the best quality you can get of a 10W/40. If oil or air filters are hard to source, then whilst you could make your own air filter, is it not possible to get oil filters from e-bay and imported? Do you get hit with customs duty if you get something sent in from e-bay?

Ford Fiesta - oil for 1.4 tdci - MrEckerslikefromRamsbottom

Done a bit more research--- If it's Euro IV with a Diesel Particulate Filter, it seems you need a 'low SAPS' oil to C1, C2, or C3 specification in order to protect against the DPF blocking too quickly,, and most of those seem to be pretty thin oils.

Ford Fiesta - oil for 1.4 tdci - thunderbird

Why do people think they can do better than a major manufacturer like Ford.

Ford have spent millions of pounds and 10's of thousands of hours on the dyno and on the road testing various specs of oil before deciding on the correct one for thier engines. The engines are dismantled and inspected for wear and the enmission systems are checked for sludge etc.

Just driving a few thousand miles will prove nothing.

Ford Fiesta - oil for 1.4 tdci - fordfanindia

Nope no DPF.

Until Euro 3, the engine was imported from UK but for E-IV, they started making/assembling it in India itself. I suspect they tinkered with the EGR and intake manifold more and made it (more) complex.


The wiki page about the DPF in the E-IV is not applicable to India; i have heard from Ford itself that there is no DPF in India specific E-IV version and it can be seen that there is no DPF after that cat-con cylinder.

Yes, 5W40 is available from Castrol, Selenia and Shell in India. I guess it is fully synthetic, so perhaps using that i can extend the oil service interval to 10k or even 15k km?

Other parts are easily available- sakura oil filter and ford spec(or even better) air filters.

Yes, Ford would have done millions of km test drives, but suggesting the same spec oil for UK and India? That would point to the economy of volumes; seriously, it is not my(and others) over-smartness but the mechanical empathy i have for this small engine when it cries it's lungs out on the highway for lack of better lubrication.

Ford Fiesta - oil for 1.4 tdci - thunderbird

but the mechanical empathy i have for this small engine when it cries it's lungs out on the highway for lack of better lubrication.

If you honestly think that changing the oil to a non Ford spec will make your car run better you are clearly not thinking through the issues. If its running porrly there is a fundamental problem with the engine.

Yes, Ford would have done millions of km test drives, but suggesting the same spec oil for UK and India? That would point to the economy of volumes

Ford, like all manufacturers test in all climates. Sometimes they specify different oils for different countries/climates. If Ford needed to do this for the Fiesta TDCi they would. Having different oils in different countries where necessary adds nothing to the manufacturers costs.

Ford Fiesta - oil for 1.4 tdci - Manatee

See Mr Eckerslike's post above - the hanbook permits 40 weight oil in hotter climes.

With a minimum ambient temperature of 20C, it must be irrelevant whether it's 5W or 10W.

Re-reading the thread, it seems the concern is that the oil is not lasting.

3 options -

- try better stuff if you can find it - same spec but higher quality

- try thicker stuff (5W40 or 10W40)

- change it more frequently

or try a combination of two or all three of those.

If the standard oil is cheap then I just do more changes.

I don't suppose the engine itself runs much hotter in India than it does in UK, once it's up to temperature and assuming the engine isn't overheating. It will also have the benefit of never having clap cold oil.

Ford Fiesta - oil for 1.4 tdci - slkfanboy

Oil of the same spec is pretty much the same regardless of manufacture, so comma is more or less the same as Shell oil. The less being shell may have more additives.

It’s assumed by many that oil degrades in the engine and hence you need to change it. What actually happens is that contaminates build up in the oil effectively diluting it. This especially noticeable in diesel engines.

To make us believe one car is cheaper to service than another, manufacturers work out the absolute max mileage they can go between services with the car falling apart to soon.

So rather than using better oil that really won’t help you, changing the oil more often, every 6000K miles would be optimal.

Ford Fiesta - oil for 1.4 tdci - MrEckerslikefromRamsbottom

I agree with that. I change the oil and filter in my Fiesta 1.4Tdci twice a year, which is roughly 6000 miles between changes.

One contributor above has found the 'Triple Q' 5W/40 from Eurocarparts which seems the cheapest fully synthetic you can get and come with your choice of oil filter. I got some and at that price I did an extra oil change! As you say, the big problem with a diesel is the build up of contaminants - and the EGR has a lot of blame for that.

My regular choice of oil for my high-milage diesel is Comma 'Syner-D' 5w/40 fully synthetic. But it's expensive and my pension isn't a right lot.

With no DPF, our Ford fan in India has a better choice of oils. I would say - use a 5w/40 fully synthetic and change every 6k miles. Do not extend the oil change interval on these engines! They don't like it! They don't rightly like thick oils, neither.

Have you noticed this little factoid about oil changes on the 1.4Tdci? --

The oil filter housing has one of those sizes where either an old Imperial 1-1/16" A/F or its metric equivalent of 27mm will fit.

The oil drain plug comes out with a spark plug socket - one of the big ones for 14mm spark plugs.

Strangely, the sun is shining in Ramsbottom today. And I'm under the car trying to find out how to remove the auxiliary belt and alternator, because my alternator has just failed at 185K miles. Proper miffed I am.

Ford Fiesta - oil for 1.4 tdci - thunderbird

The oil filter housing has one of those sizes where either an old Imperial 1-1/16" A/F or its metric equivalent of 27mm will fit.

Be very careful giving advice like that. Some time ago I was involved in the Kit car scene and most cars of the period used Ford X-Flow engine with the traditional 3/4" thread. Due to their compact size a vast majority of people used the old Renault 4 or 5 filter which had the same imperial thread. But unknown to Kit car people at large Renault changed to a metric 20mm thread back in the early 80's and only years later did the imperial filter get deleted from the supplier catalogues. Owners kept buying the "Renault" filters and a spate of failures started occuring where the filter came off normally at high revs and mostly on track days.

One clever owner spotted what no one else had spotted, the 20mm filter would fit and tighten onto the 3/4 thread perfectly but was not secure enough once under pressure.

Whilst some owners managed with some difficulty to source the Renault filter with the correct tread others changed the threaded spiggot on the car to metric enabling them to use the newer metric filter. The sensible owner simply used the early Ford Ka filter, slightly bigger than the Renault one but way smaller than the OEM filters and readilly available with the 3/4" thread.

Ford Fiesta - oil for 1.4 tdci - MrEckerslikefromRamsbottom

Well pointed out Thunderbird. Never mix your screw threads when a metric nut seems to fit on an Imperial thread! It might seem to, but it won't! (Though I have used Whitworth on UNC and vice-versa when I've been stuck).

What I was pointing out is that on this engine, there are a few hexagon sizes where the metric size has a direct A/F inch-size equivalent. For instance, if you were to buy a set of spanners of both metric and Imperial sizes, there will most likely be no 16mm spanner, because the 5/8" A/F is the same size, as I've found out whilst taking me alternator off!

So this PSA-designed engine has been thoughtfully set up so that you can do an oil and filter change if you have an (old-fashioned?) Imperial tool set or a metric set. There will be, of course, a spark-plug socket in each (which fits the sump plug).

The oil filter on the 1.4Tdci is an unusual design. It is a paper element in an alloy housing which sticks up at an angle from the side of the engine. It looks like a little squat bottle with a hexagon cap, and it's this cap which takes the 1-1/16" = 27mm socket.

Ford Fiesta - oil for 1.4 tdci - MrEckerslikefromRamsbottom

Our friend from India----

There are one or two things that you can do to help the noise problem on a 1.4 Tdci. The air pipe from the front grill to the back of the air filter must be firmly connected to front cross-member and the joints between the sections must be firm and the connection between the pipe and the back of the air filter must be firm. A lot of noise (I found) can be generated if the air pipe is loose on the back of the air filter.

Have you checked the gearbox oil? Often overlooked! Get the car level where you can reach under the front bumper. Unclip the plastic shield from the front of the gearbox and look for a hexagon-socket screw. Remove this screw with a (If I remember correctly) a 8mm hexagon wrench. It's a level plug, so pour some gearbox oil, 75W/90, into a pump-action oil can and squirt it in until the oil starts to run out. Replace the plug -tight. Job done.

Ford Fiesta - oil for 1.4 tdci - fordfanindia

Air filter connections are tight.

Here Ford says that gearbox oil is filled for lifetime; since car is fairly new(2.5 years / 35,000 km) i don't think they need replacement so early considering that it is synthetic oil that is filled.

The noise i was originally referring to is the tappet noise from the head as if it is being starved of oil. Hence asked about any better oil for better lubrication.

------------------------

The previous ford i owned is a version of fiesta with 1.8D (non-turbo) engine. I used 2T oil with the diesel and it worked wonders to engine smoothness. Wary of trying the same in the tdci engine!

Ford Fiesta - oil for 1.4 tdci - thunderbird

The noise i was originally referring to is the tappet noise from the head as if it is being starved of oil. Hence asked about any better oil for better lubrication.

Many people in the past have thought that using a thicker oil will stop tappet noise, totally wrong.

Ford specified a 5w30 oil because in early DOHC Zetecs the 10w40 they originally specified was too thick to circulate (especially when the engine was cold) and caused noisy tappets and acclerated wear of those components. They admitted it was a bodge but it was a bodge that has stood the test of time, over 20 years and that viscocity oil is used in most modern Fords to this day..

That is why you are being warned not to use a spec that Ford do not recommend, they know a thing or 2 about their engines and what oil makes them work best.

Only cure for noisy tappets is either get them shimmed (if mechanical) or replaced if hydraulic. Not sure which the 1.4 TDCi uses.

Ford Fiesta - oil for 1.4 tdci - jc2

Ford no longer specify 5W/30 for most of their engines;it's now 5W/20.And has been for about 2 years.Even Halfords now stock it.

Ford Fiesta - oil for 1.4 tdci - thunderbird

Ford no longer specify 5W/30 for most of their engines;it's now 5W/20.And has been for about 2 years.Even Halfords now stock it.

Just done a bit of Googling and discovered the following:

5w20 is indeed a current Ford spec but only for the new Eco boost engines. The Ford spec number is WSS-M2C-948-B.

The correct spec for most Ford engines is WSS-M2C-913-C which is a 5w30 fully synth oil. This replaced the earlier WSS-M2C-913-B spec which was a semi synthetic. There is also a new WSS-M2C-913-D spec which came out in about 2012, still a 5w30. These specs are backwards compatible enabling older vehicles to use the newer spec oils. Obviously if your engince requires the new D spec using the earlier C or B spec would be daft or dangerous.

Some sources say that the WSS-M2C-948-B is suitable to use in the 1.25, 1.4 and 1.6 petrol engines but no mention of this on the official Ford site. No mention anywhere of this being sutable for diesels.

Ford Fiesta - oil for 1.4 tdci - Wackyracer

Some sources say that the WSS-M2C-948-B is suitable to use in the 1.25, 1.4 and 1.6 petrol engines but no mention of this on the official Ford site. No mention anywhere of this being sutable for diesels.

You only have to look at the specs. If it says A5/B5 then it is suitable for petrol and diesel engines.

A - Petrol engines

B - Diesel engines

E - Diesel engines (heavy duty).

Edited by Wackyracer on 07/07/2014 at 13:18

Ford Fiesta - oil for 1.4 tdci - MrEckerslikefromRamsbottom

I wasn't saying to replace the gearbox oil.. just to check the level. It can go down, so don't just trust to it being filled for life.Had to pump quite a bit into mine when I first checked it at about three years old.

What sounds like tappet noise on these is often injector noise. The tappets are hydraulic and in general make no noise. A leaking injector seal can make a very noisy tapping noise.

It's injector noise that comes back up through the air filter if there are any gaps or looseness in the air pipe up to the back of the filter, which is why I suggested checking the air pipe and its connections, especially the join at the back of the air filter assembly. And ensure that the little plastic box on the front grill end of the air pipe is screwed firmly to its housing. If that one screw comes out and the end of the air pipe is vibrating around behind the grill, it can cause all sorts of bad running as pulses of air go up the pipe!

I run mine with the 200:1 dose of two stroke oil. Modern diesel is low in sulphur and hence has had some of its lubricating property removed. The 2T oil does seem to give smoother running and less smoke. However, 2T oil is generally quite expensive and the cheapest I can get is from Morrisons supermarket at £2 for 500ml. I've been using it for two years now.

Ford Fiesta - oil for 1.4 tdci - MykiMyk

I'm interested in more detail about adding 2-stroke oil to diesel in the Fiesta 1.4 tdci.

cheers

Ford Fiesta - oil for 1.4 tdci - edlithgow

I'm interested in more detail about adding 2-stroke oil to diesel in the Fiesta 1.4 tdci.

It should be a low ash oil meeting NMMA requirements for TC-W3 (or iso GB, JASO FB or higher). People use it as an upper cylinder lubricant in petrol engines too.

Fuel economy benefits are claimed, but are of course unproven.

Its used at high dilutions, say 1:500 or higher, where it shouldn't have much impact on exhaust catalysts or mixture in petrol engines.

In a diesel I suppose you could use it at any dilution you wanted to afford.

In a diesel I'd think the main benefit (if any) might be to improve fuel pump lubrication.

Edited by edlithgow on 05/12/2018 at 00:00

Ford Fiesta - oil for 1.4 tdci - MykiMyk

late to the party regarding heavier oil for the Fiesta 1.4 tdci engine but I too am now going down the same road.

I have a 2002 Fiesta 1.4tdci with 220,000 on the clock, runs like a dream and uses no appreciable amount of oil. She's breathing a little now and getting a little noisier so I too am considering a 5w40.

The 1.4 tdci (as denoted by Ford) is the DLD-414 engine built in equal numbers between Ford and PSA. It was fitted to a number of cars by Ford/Citroen/Peugeot/Mazda/Suzuki/Toyota; see link: en.wikipedia.org/wiki/Ford_DLD_engine

Ford are the only manufacturer using this engine to specify a 5w30 using their own WSS-M2C913-B (a spec which covers a number of unrelated diesel engines) whereas all other manufacturers specify a 5w40 using ACEA A3/B4 conformity (look up a few cars for sale with these engines and use the reg numbers in an oil supplier website and you'll see what I mean).

The difference between Ford and all the other manufacturers in their oil spec seems to have little logic unless maybe??? 1) Ford got the mpg down by using a ligher oil 2) Ford attempted to standardise their diesel engine oils 3) there is something unique about the Fiesta installation.

To further muddie things, WSS-M2C913-B and ACEA A3/B4 are quite different specs.

As you can see, I've done quite a bit of my own research on the subject and been in contact with 2 respectable oil specialist today and eventhough I noted the oil being used by all other manufacturers is different to Ford with this exact engine they were both unwilling to deviate from the Ford specification.

Have any of you guys here managed to work through this and still have good engines after doing the 5w40 swap?

Ford Fiesta - oil for 1.4 tdci - edlithgow

It’s assumed by many that oil degrades in the engine and hence you need to change it. What actually happens is that contaminates build up in the oil effectively diluting it. This especially noticeable in diesel engines.

Both these things happen.

To be an explanation of your reported symptoms, the "contaminates" would have to be fuel dilution, which would reduce the viscosity of the oil.

Soot is the characteristic contaminant of diesel engine lubricant, and it wouldn't be expected to reduce the viscosity, though it can promote wear.

You may be able to get some indication of oil condition, particularly fuel dilution, with a crude chromatographic test. comparing new and used oil.

Look up "blotter spot test" on the Internyet

Alternatively, you MAY be able to send an oil sample to a commercial lab for analysis (maybe not in India) though that is likely to cost as much as an oil change.

From the expert opinions expressed here, it seems likely that your symptoms are mechanical, but if you want to follow up the oil angle I'd suggest you consider posting on the US-based Bob Is The Oil Guy forum (I'm afraid it really is called that).

There's some expert industry opinion on there, though of course there's quite a lot of Good 'ol Boy inexpert opinion as well.

Ford Fiesta - oil for 1.4 tdci - edlithgow

Ford, like all manufacturers test in all climates. Sometimes they specify different oils for different countries/climates. If Ford needed to do this for the Fiesta TDCi they would. Having different oils in different countries where necessary adds nothing to the manufacturers costs.

I understand Ford (and other manufacturers) often spec. lower viscosity oils in the United States than they do in, for example, Europe or Australia. This is likely to be more due to the regulatory climate rather than the...er...climatic climate.

In the US they have for many years had to meet CAFE average fleet economy targets or face financial penalties, and using skinnier oils has helped them to do that..

Improving fuel economy slightly at the expense of a slight increase in wear is a reasonable compromise from most owners perspective as well, since most cars are scrapped for reasons other than engine wear.

However, if you want to bias the compromise more toward protection, say for an unusually old car that doesn't do a lot of miles,(me), or due to an excess of mechanical sympathy (the OP) thicker oil may be indicated .

Ford Fiesta - oil for 1.4 tdci - blackfire

Hey there buddy,

Even I hail from India, the northern part of the country though & I think I understand what you are talking about. From my experience on a Ford Figo with the same motor, the 5W30 that the company fills in is just not adequate.

It loses its viscosity within a few thousand kilometers and gets the engine temparatures rising upon a spirited drive. I would say that its not as much the SAE grade thats the culprit but the quality of oil maybe. So, without getting into details, I have found that the Shell Helix Ultra 5W40 is the most economical, easily available and suitable oil for this motor in our climatic and driving conditions. It keeps the oil pressure at right spot on thevguage, keeps the temps within nornal ranges and just makes sound and feel so much smoother.

If fully-synthetic is not your cup of tea, I would suggest trying the 10W40 from Total. These French engines do seem to like the French fluids better, especially if its a 10W40 semi-synth.

Do keep us posted on what you finally chose.

Ford Fiesta - oil for 1.4 tdci - skidpan

Ford are the only manufacturer using this engine to specify a 5w30 using their own WSS-M2C913-B (a spec which covers a number of unrelated diesel engines) whereas all other manufacturers specify a 5w40 using ACEA A3/B4 conformity (look up a few cars for sale with these engines and use the reg numbers in an oil supplier website and you'll see what I mean).

The difference between Ford and all the other manufacturers in their oil spec seems to have little logic unless maybe??? 1) Ford got the mpg down by using a ligher oil 2) Ford attempted to standardise their diesel engine oils 3) there is something unique about the Fiesta installation.

To further muddie things, WSS-M2C913-B and ACEA A3/B4 are quite different specs.

The Ford spec not only relates to viscosity, its also related to emmision control kit. Fords equivalent ACEA spec is A1/B1 or A5/B5.

Ford have spent many years developing their specs and know a thing or two about their products. I always use what the manufacturers specifies, it totally stupid not too.

But if you know better and can develop products over millions of miles of testing go-ahead. You may be an expert but we all know the definition of an expert (an ex is a has been and a spert is a drip under pressure.

Ford Fiesta - oil for 1.4 tdci - MrEckerslikefromRamsbottom

In another post, the original poster explaind that he wanted to change the oil in order to overcome 'tappet noise'. Of course, this 1.4Tdci engine is famous for blowing injectors, which sounds like tappet noise to the untrained ear.. I drove for quite a while with what I thought was tappet noise until it went in for an MOT. The emmission test of a couple of minutes at high revs saw off the leaking injector and they gave the car back to me - banging and with smoke coming out of the bonnet. In it's 217,000 miles, it's now had new seats and seals three times. My local garage mechanic has bought a Ford Fusion with the same engine. His first job was to re-seat the injectors as his wife driving it reported that she was passing out from the fumes. On my Fiesta, for the last hundred-and-odd thousand miles, I've been using 5w40 oil.

Ford Fiesta - oil for 1.4 tdci - MykiMyk

had an interesting time in the summer with that infamous tappet noise. I went with the consensus and did the injector seals first (that noise + some carbon around injectors + a faint diesel smell in that area). the upper support seals were missing which wasn't a good sign. new support and spill seals fitted plus a belt and braces method with the copper seals. took the noise down a bit but I didnt get lucky this time.

went on and did the hydraulic tappets which made it sound like a refined engine again.

considering the compacted fine silt that came out of the tappets and the rocker cover condenser bowl, I've decided to go back to the old fashioned 6000 mile/6 month method to keep things clean inside, revising to 5w30 in winter and 5w40 for the summer.

now at 226,000 miles, no oil burn, 66 - 68 mpg mixed driving.

Ford Fiesta - oil for 1.4 tdci - edlithgow

That Mobil Delvac MX 15W/40 seems to be good stuff. Wish I could still get it here in Taiwan but I'm on my last jug. Latterly I've been using it mixed 50:50 with CPC SAE 40.

In a hot climate you don't want or need skinny oil or oil with a low number before the W. You probably don't need a multigrade at all, but if you can't quite manage a straight weight, minimising the range of the multigrade is good practice.

I could run a straight 30 but I havn't seen any). Straight 40 is just a bit much for local conditions according to the handbook, though it would probably be fine)

Multigrades achieve their magic with viscosity improvers, which are polymers akin to synthetic pencil eraser material. These shear , and their degradation products can gum up piston rings over time. I believe this is why Detroit diesels, which are 2-stroke and rough on oil, specify straight weight oils and prohibit the use of multigrades.

Thicker oil protects better but slightly increases fuel consumption. The popular story about skinny oil getting to the top end faster seems to be incorrect within the range of pumpability of the oil, which any temperature above freezing will be. Oil pumps are positive displacement, so they deliver on a volume basis irrespective of the viscosity of the oil.

Ford Fiesta - oil for 1.4 tdci - gordonbennet

Thicker oil protects better but slightly increases fuel consumption. The popular story about skinny oil getting to the top end faster seems to be incorrect within the range of pumpability of the oil, which any temperature above freezing will be. Oil pumps are positive displacement, so they deliver on a volume basis irrespective of the viscosity of the oil.

Now that is an interesting post, flying directly in the face of the latest must have, the wateriest thin oil possible.

I tend to agree with you, and i'll give my own Landcruiser as an example.

In the book the almost standard 5W30 is recommended, though when i had my previous Hilux the Toyota dealer used 10W30 or even 10W40 as i recall, despite same engine and same standard oil suggestion.

The 3 litre Diesel in these is a heavy old lump, not particularly fast revving, and i admit being old fashioned i'm not convinced by this ultra thin oil in such Diesels, the handbook advises quite a wide range of oils can be used in British temperatures, so for years my go to oil has been 5W40 full synth, Shell Fuchs Morris or Millers, still very thin it must be said.

The problem with 5W40 is that it's almost impossible to find Diesel specific oil in that grade, and i've had a hankering of going back to Diesel specific engine oil for the better cleaning properties.

I should add my engine also started to sound a little injector type rattly around 2000rpm, especially when cool on a trailing throttle.

Anyway, i've had very good experience with Exol oils, and lo and behold they offer a 10w40 semi synth Diesel specific oil (not meant for DPF engines) at a ridiculously low price (some £46 for 20 litres), so i tried some as an experiment, result a much quieter engine from cold and right through the rev range, and the oil light goes out faster on the first start of the day.

I'm not suggesting this is in any way something anyone else should try, it doesn't need to be full synth because i change it every 6 months anyway, any extra fuel usage is a moot point because a 2+ ton brick is never going to be an economy machine and i'm more interested in the thing lasting than saving pennies.

Edited by gordonbennet on 02/12/2018 at 10:38

Ford Fiesta - oil for 1.4 tdci - edlithgow

Not simply my own opinion. (I'm a biologist). I'm essentially paraphrasing/summarising the drift of informed opinion on the Bob is the Oil Guy website, which I used to frequent until banned (must be a Groucho Marx quote there somewhere), and where this topic was often discussed by folk who appeared to know whereof they spoke

I'm pretty confident it applies to ancient flat tappet designs like my (and probably your?) engine.

I'm slightly less confident that it always applies to more recent designs with perhaps constricted hydraulic tappets, though I think it probably does, because I'd have expected the exception to have come up in the frequent discussions otherwise.

Skinny oil saves (a little) fuel, thick oil prevents (a little) wear.

I think diesel spec lubricants give a lot of bang for the buck and the extra detergency may be of value in neglected (or just ageing) petrol engines too.

My old engine now looks very shiny inside (1:1 Mobil Delvac MX 15W/40: China Petroleum Corporation SAE 40, both mineral, for the last 6 years) and has lost the varnish sheets that it had when I got it.

Ford Fiesta - oil for 1.4 tdci - edlithgow

Research paper on the effect of low viscosity oils on heavy duty diesel engines.

www.researchgate.net/publication/307585091_Low_vis...d

Unsurprisingly, wear is generally greater with low viscosity oils, though from a quick scan they don't look at cam wear, which would be the focus of my concern.

The sponsor Mahle (potential commercial bias?) say they have upgraded components that can make up the difference,

Nice for them, but not so good for you if your engine doesnt have them.

Edited by edlithgow on 31/12/2018 at 01:33

 

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