Fuel additive engine cleaners

[MuddyPaws]

Having recently bought a 64 plate diesel CX5 with 24k on the clock I have avidly been reading this forum ever since. I’ve read a lot about engines coking up and am now more than a little apprehensive about having an expensive future ahead.

I’ve occasionally used fuel additive engine cleaners in the past to get an old 02 plate diesel Skoda through MOTs and wondered if these would help safeguard against coking in my CX5? Some additives raise the cetane rating of the fuel and I also wondered if this would cause problems with any of the engine monitoring systems on the CX5?

[Bert321]

What type of driving do you do? Short runs/motorway etc?

[MuddyPaws]

A mix of the two really Bert123. It’s not used for commuting so gets occasional use for 20 miles or so, plus longer motorway holiday trips.

I found out today that the latest software update is 59.005.02 but I haven’t found my way through the settings to find out if mine has the most up to date version. I understand some improvements were made to help combat coking.

[Clarice]

All the furore about Diesels and this bunch of idiot politicoes gets my Goat. Firstly Diesels are cleaner now than they ever have been due to advances in engine build and design along with electronic monitoring for best performance/economy.

The current crop of diesels have euroTec 6 (Yours is euroTec5) which means they have to achieve a certain PPM of emissive product, this is curtailed in part by the DPF ( Diesel Particulate Filter ) which essentially collects the particles emitted by the engine and through Heat Energy reduces these particles to ash, it is on long runs self cleaning as the exhaust temperature will hit high enough to carry this out automatically and you need do nothing else.
 
On short runs and it would have to be a fair number it would eventually clog up and cause your pocket around £1000. Most manufacturers have sensors on the DPF which will alert you to it needing cleaning before it reaches this stage however but if you ignore it...............pay out

However there are  companies that now offer a clean up for clogged DPF's at a lot less cost than a new one.

Additives nowadays may do little or nothing as the diesels today are a lot more advanced than they were running cleaner and more efficiently.

Cheaper to just give her a long run once a week to keep it healthy

[ROCKETRON]

I think that there has never been a lot of proof that the additives help anything but I would say if you regularly use supermarket diesel then extra additives may help as that is what supermarket fuel tends to be missing as the basic diesel is all the same. By the way all cx5’s are EU6 emission standards.

[Bert321]

A mix of the two really Bert123. It’s not used for commuting so gets occasional use for 20 miles or so, plus longer motorway holiday trips.

I found out today that the latest software update is 59.005.02 but I haven’t found my way through the settings to find out if mine has the most up to date version. I understand some improvements were made to help combat coking.

Your driving doesn't sound too bad - it's lots of short drives modern diesels don't like.  These Skyactiv diesels are all Euro 6 compliant (as per Rocketron's advice above), and have DPF filters.  At specific mileage intervals the car tries to do a regen of this filter, but certain criteria needs to be met: the enigine needs to be warm, the revs above 2000 etc.  However in my experience in my current CX-5 and my previously owned Mazda 6, regens happen (irrespective of engine revs) every couple of hundred miles, as long as the engine is up to temp, and can last up to about 15 mins.
My commute is 22 miles on fast roads, and each time it does a regen I try to 'help it along' by keeping my revs up.  However, sometimes it starts on a short journey and gets interrupted, and (in theory) some diesel gets dumped into the sump, thus increasing the oil level.  The dipstick has an X mark above the high level, and when this X mark is reached you need to get an oil change done.
I've just covered a year and 10000 miles with no increase in oil level, and with an oil dilution reading of 0 according to a reading using Forscan - so it seems driving about 20 miles regularly on a journey is enough to keep the engine clean.  However, not long after buying my car, and about 7 weeks and 6k miles before a service was due, the oil pressure warning light came on, requiring an oil & filter change and a software update - perhaps this was due to a former owner doing only short runs?  Or perhaps bad luck?  I don't buy supermarket fuel and at least every other tank fill up is with the premium grade diesel from Shell or BP - maybe this helps too?