Additives

Stephen explained on 16/02/2009

I have not tried diesel injector cleaner, but I have tried the petrol injector added to the fuel tank - it worked to my entire satisfaction twice, as in no doubt in my mind and I am quite sceptical.

In my diesel car i just added a litre of ATF to the tank with good results.

- As per recommendations here.

Tom

I think that most of these cleaners, petrol or diesel, are essentially paraffin (the bottle will say it contains kerosene) apart from those which are essentially meths.

I've never been able to find out what Redex is made of though.

Mark W laid this down on his screen :

I read somewhere that Petrol injector cleaner, the version you add to your tank, is nothing more than a mix of ATF fluid and paraffin.

I bought a single dose bottle about ten years ago for the car I happened to own then, tried it and it seemed not to make any difference at all which I could detect.

In Jan 2008 my car came very close to failing emissions and the fix was suggested to be to try some Injector cleaner in the tank. After adding it my mpg shot up and the power seemed to improve too. I gave it another dose in Jan 2009 and my mpg once again made a noticeable improvement - not so good as the first time, but noticeable. When I took it in for its most recent MOT it flew through the emissions.

I used STP for all three doses, but I would guess there is probably absolutely no difference between them.

Sorry if I am being thick: what is ATF?

Stephen gurgled happily, sounding much like they were saying:

Automatic Transmission Fluid.

Stephen pretended :

Automatic Transmission Fluid - the stuff you put in an automatic gearbox. I don't know how it differs from any other oil, so don't ask :-)

It's pink and frothy. Has detergent in.

Co-incidentally I've just had my Renault Laguna 1.5dCi in to the main dealer for its first service where they added injector cleaner. I queried this, saying that I understood manufacturers advise against using any additives, but I was assured that this is not the case with diesel engines! HTH Patrick

I think you'll find the additive for cleaning petrol injectors is mainly composed of xylene. A derivative of benzene. Maybe it's also suitable for diesels. Mike.

Redex only make one product - the "red stuff". It is variously marketed as petrol injection cleaner, diesel injection cleaner etc etc.

it is probably better in the long term to use good quality fuel in the first place, this will keep the whole system clean and avoid any need for additives.

I've never driven an automatic so I didn't know. Why does an automatic gearbox need a special fluid?

Is it cheaper to buy a bottle of ATF rather than an additive? I am guessing ATF comes in much larger bottles so you could buy one bottle that would last for months/years?

How much do you add to the tank and how often?

That's no doubt true but what is a good quality fuel and how do you tell? Doesn't all UK road fuel have to be of a certain quality by law?

Thanks.

Because of the way the gearbox operates. It's quicker for you to read up than me explain. Basically, the oil is subjected to different and more extreme forces than in a standard manual box.

Extremely. A factor of 10 wouldn't be unrealistic.

Indeed, you can buy it in 25 and 50 litre drums.

it has to be a certain minimum :)

Most supermarket fuel is of particularly low quality. Most branded fuel is better. The premium ones are better still, such as Optimax, Excellium and the like. I often recommend Esso fuels locally, they price match the supermarkets and it seems to have a better octane rating in less pinking terms.

naha, they make a green diesel injector cleaner.

I think injector cleaners are about the only 'addative' that's worth using, appart from an engine flush fluid.

all these cleaners do is clean, they are just solvents, dont add anything to the fuel to make it better like the stuff aimed at the ricer boys claims,

when i worked for a garage years ago, there was a bloke who you could call out, and for 80 quid he'd connect his machine up to the injection system of a car, and it'd run the engine, re-starting it when it died, pumping the cleaner fluid into it, took about half an hour to do it's stuff, but the end result was amazing, better than just fitting new injectors as it cleaned the rest of the fuel system too... i recall he had something that sprayed the stuff into the throttle body at the begining of the procedure,

When i was younger, i watched one of those tacky american commercials for dodgy products, this one was for some oil addative that made an old engine run like new,

they went to a scrap yard, found a car that ran like a nail (was really running with about 4 plug leads removed and on full choke it sounded) they stopped the engine, poured the magic oil treatment into the sump, then re-started it (hoping no one spotted the jump from where they cut the film to re-attatch the plug leads), it immediately ran on all 8 cylinders and purred, Q lots of dropped jaws and 'well gee, thats juyst amayzing' comments from everyone present,

And some dumb people believe this, just put the word 'magic' on the can and they cant keep their wallets in ther trousers.

"Mrcheerful" gurgled happily, sounding much like they were saying:

In some, yes. Just as in some older cars. Like my own 19yo car.

If there's a 95RON base map, then anything below 95 may be retarded, if there's a knock sensor (which most don't have) - but nothing over 95 will make a blind bit of difference.

Which, in itself, pokes a hole in your theory - since the retardation of the ignition would reduce power, meaning larger throttle openings would be required for the same performance - so more fuel would be consumed. Whether that increase in consumption is more or less than the percentage difference in cost of fuel's another question, of course. At a supermarket 2-3p/litre between 95 and 98, it's far more likely than at the 8-10p my local Shell want.

When I had the head off mine last year, it looked absolutely spot-on. A little light coating of carbon, but nothing much. I'd been using it on mainly supermarket 95 for 6mo - what fuel it'd done the previous 170k miles on, I have no idea.

In my experience not all fuels are created equal. I have never noticed any big increase in fuel economy by using better fuels (but I do not study the mpg as I run too many different vehicles to bother) but I can notice the better running on some vehicles.

I am pleased your engine was nice and clean inside, why did you have to take it apart?