Which Fuel?

[Mike169]

Hi, my car is a Rav4 2.2 diesel D cat, not quite 2 years old with very low mileage. On the fuel filler cap it has a sticker stating LOW SULPHUR FUEL. Of course it means diesel but can someone please specify what is low sulphur fuel as it runs fine on normal diesel, V power dearer diesel, even supermarket stuff when i was low which i didn't want to put in.

Also after reading many forums it says newer/later D cat diesel engines are very different to normal diesel engines, in what way please, i am mechanically minded but modern technology is now leaving me a bit behind. I am keen to find a link what makes this engine 'special' and why it works differently from slightly older variants?

Regards Mike169

[Heidfirst]

afaik all UK retail diesel should be low sulphur these days in fact ultra low sulphur.

The modern D4Ds are of course high pressure common rail diesels (as compared to pre-common rail units). What makes the D-CAT different is that it has a 5th injector that is used to supply diesel into the exhaust flow to the DPF to burn off accumulated soot etc. (this is why the D-CATs are thirstier than normal D4Ds).

[FROSTYBALLS]

Here is an earlier topic (2009) on low sulphur diesel: http://www.toyotaownersclub.com/forums/topic/101642-low-sulphur-diesel/

[philip42h]

Some opinions (rather than certified facts) :)

• All diesel on sale in the UK these days is of the "low sulphur" variety. I'm sure it used to say "Low Sulphur" on the pumps a few years ago but I'm not too sure that they bother nowadays.
• All regular diesel is pretty much the same stuff and complies to the same standards irrespective of where you buy it - be that Asda, BP, Esso, Morrisons, Shell, Tesco or Total. The "supermarket diesel is bad" is just an urban myth and 'wrong'.
• All modern diesels are designed to run on regular diesel ... and the quality of regular diesel available in the UK is, generally, perfectly fit for purpose.
• Premium diesel contains additives that help the engine burn fuel more cleanly and that is generally a good thing (and probably well worth paying for) particularly if you are doing loads of short runs.

I'll leave those with a much better understanding of diesel engine design to answer the last part of your question ...

[Mike169]

Ok thanks all, so the fact on my front wing it has a Badge that says D CAT does it still have a cat somewhere in the exhaust system or does the 5th injector take care of the emissions side?

[Heidfirst]

yes, it still has a cat.

http://www.toyota-europe.com/inside_toyota/environment/green_technologies/advancing_with_diesel.tmex

[Mike169]

Heyyyy Scott you are being a great help, thanks......................does my car still have a EGR valve? Just that i have read forums about people blanking them off, not that i have a wish to, more so i am just trying to understand the technology of my car.

Would i be correct in thinking a D Cat engine is like the next generation?

Regards Mike169

[Heidfirst]

yes, it still has an EGR.

Well, it was meant to be next generation at the time but no one else has adapted the technology & as I said it makes the engine noticeably thirstier than the standard 2.2 D4D that it's based on.

I suspect that it will prove to be an abortive branch of diesel technology.

[philip42h]

... all of which means that the engine collects 'soot' and other particulate matter that needs to be 'burnt off' within the catalytic converter when the engine is at temperature and on a longer run. If you are regularly doing long runs 'on the motorway' (say) this will all take care of itself without you noticing and pretty much irrespective of which brand / grade of diesel you use. If your pattern of driving is predominantly short runs etc. you will be better off using cleaner burning premium diesel but you'll still want to plan in a decent 'blast' every now and again.

[Mike169]

Hi all, i appreciate all the information. I am a diesel technician from the past if you like, i have changed many a V8 in a Ford D series truck in my past, Perkins, Cummings, and own a boat with 2 x straight 6 Ford diesels in it with turbo's developing 150 bhp a piece but when the smart phone's and it's respective generation come out i am starting to lag behind.

Backtracking, my D Cat Rav 4 does very short runs and i appreciate now it will need a clear out as often as is realistic to clean the system out as i can see the engine will only choke itself up and i can appreciate higher quality fuel is a good idea.

Maybe the design of engine in my car may die off in years to come or maybe it will become the norm, 5th injector, in my mind that was for starting not fr burning off excessive fuel.

I have no idea but yes it is thirsty, 2.2D auto average local mpg around 29 and not much better on a decent run, from past experience diesels are not much more more economical than petrols on short runs due to the way the rack operates in the injector pump and petrols can actually be more efficient in certain running conditions.

Thanks for all the information, Mike169

[gjnorthall]

The supermarket fuel issue has been with us for year and whilst all fuels sold in the UK meet the relevant British Standard - this doesn't mean that all fuels are equal. I'm biased against supermarket fuel based on what I've seen working on engines for many years but accept that others will have a different view. To me, it's an academic argument - it costs less than a £1 more to fill up at a local Shell station than Tesco / Asda - and now Shell give Tesco points.