Redex – Diesel engine cleaner

I have an older Audi 4and it's done about 135,000 miles. I'm very happy with it and have no plans to upgrade but as the miles rack up I'm becoming aware that the car needs more care.
Does the Redex stuff that you put in with the fuel actually work? I service the car every 12,000 miles.
Cheers

I put Redex in an old Morris Minor once (in the fuel and straight into the carb).

It certainly cleaned all the old fuel gum and carbon out. I was followed by clouds of white smoke for miles.

I think it did for the engine though – the build up of carbon deposits was all that was keeping it air, water and oil tight.

Unless you have a specific problem I'd just carry on with regular services and monitor fuel/oil consumption etc to see if there's a specific problem that needs addressing.

i use it in the wifes 1.4tdci fiesta and the garage where we get it serviced uses it on all diesel's aswell.

i think they use Wynnes though not redex

I've used it a few times and the garage has put it into my car before as well.
Best done into a full tank and just before a long motorway run. Be prepared to be followed by a small cloud for a little while… 😉

Interestingly the nonsense claims made on the bottle/ packaging of Redex and all the other potions are not subject to the rules of the Advertising Standards Authority. So the claims can be as amazing, credulous and rediculous as Redex feel, without the incumberance of fact or proof.
http://www.which.co.uk/reviews-ns/fuel-additives/index.jsp

I use Millers in my old Nissan Serena.

Millers Halfords link

I was not going to be taken in by all the hype but I gave in and tried it to see and was fairly impressed. Less smoke, less noisy as well. I have no power in the Serena motor anyway so I have not noticed any difference there.

I ran out of Millers a couple of fill ups ago and have noticed the engine sounding a little bit noisier again… could be my imagination though…

on my petrol car, I'd be pretty worried what all that crap going through the cat will do to it.

If it's still passing MOT emissions tests, why bother?

I had a similar dilemma last week – hearing in the news that fuel will likely hit £1.20 a litre very soon, I knew I had to do something to try and get my motor's mpg up a bit. It's a Peugeot 307 2.0 Hdi and should supposedly be getting 50mpg+ but only comes back with 42mpg max. I've been driving it embarrassingly slow and calmly to try and get the figures up – without any success.

So I've turned to Redex. Presumably these things must do something – although so far I'm convinced it's a placebo!

http://www.honestjohn.co.uk/forum/post/index.htm?t=35033

Good link there Macavity. Thanks for that.

I use the Miller Oils stuff you can get for diesels. Put a double dose of that in to a full tank (and if the diesel is BP Ultimate or Shell Performance all the better) and run that through. I promise you will notice the difference.

I ran out of Millers a couple of fill ups ago and have noticed the engine sounding a little bit noisier again… could be my imagination though…

That'll be the cetane improver then.

Redex itself is meant to clean the injectors and fuel system. I think it does, it may make a very slight difference if your engine is really cacked up; it's worth a shot once in a very old car I'd say, or if you do a lot of short trips.

What dinger is talking about sounds to me like he got the redex diesel stuff that comes in a bigger bottle, it contains cetane improver. A high cetane number is a bit like having a high octane number in a petrol car, except that it'll benefit any diesel engine; the engine does not have to be designed around higher grade fuel like a petrol one does. Higher cetane fuel may improve economy a bit (some say it does) but it will definitely make the engine quieter (due to slower burn I think?) and start better. BP Ultimate diesel is higher cetane, but you can also raise the cetane rating with an additive as above.

Daveaasmith – there oculd be a load of reasons why your motor is less economical, but remember driving slowly isn't all there is to it. You need to maintain speed as much as possible. So if you are on the motorway and you let your speed creep up, then you slow down and repeat, you will get crap MPG even if you're only doing 60.

Accelerate reasonbly up to speed then hold it, make sure you are not creeping up. You can get very good mpg by accelerating briskly then letting your speed slow very gently but it's a pain do to and would really piss off othe traffic 🙂

You're better off running Vpower at each fill-up IMO, long term small-scale cleaning is more likely to be useful than using naff fuel and dumping a magic potion through it every few months, and the costs are comparable when you think about it.

Personally never use it on my HDi as a) it says specifically not to and b) I've heard literally dozens of stories of high-pressure pump failure within 1 tankful of adding additives. Not for me with such poorly proven "benefits".

When I bought my TDCI Focus (with 100K miles) It was "OK", it ran fine but only averaged about 45MPG, and 50 on long trips, which was very disappointing.

It failed it's first MOT on emissions, and the garage blasted a load of that cleaner stuff directly through the injectors. I immediately got a really big improvement in MPG. Long trips were 10MPG better, and running about was 5MPG better. Nowadays I use if every few tankfuls and it's passed all it's last 3 MOT's with no problems, and will give me at least 65MPG on long trips with a light foot.

I am a (previously sceptical) convert.

carrot – which one do you use?

I have used a can of spray-into-the-intake stuff which costs £20 before. That actually made a fair old difference to smoothness, hard to say if it helped with economy – this was on a car that was getting sporadic use and had no trip computer.

http://www.carbibles.com/fuel_engine_bible_pg3.html

First car I got to 217K miles before someone pulled out in front of me killing it, current car is on 138K miles.

I'd up your service intervals to 6 or 9K miles for oil, oil filter and air filter (you can make the air filter last longer by giving it a blast with an air compresser). I use an engine cleaner too and drain the fuel filter – I half the interval to swop out the fuel filter.

I drop a redex into the car about every 3k miles – That tank always gives me an ~5-10% increase in mpg and it feel smoother, after that the mpg drops back to ~48 but things still feel better.

How much is in my head about the smoothness I couldn't say but for the 6 yoyos it costs me I'll keep doing it (although I'm getting tempted by that acetone stuff after reading a few places).

Molgrips, Cetane will have a minimalistic improvement on Diesel, unlike Octane on a Petrol…….. Cetane is the speed at which the Diesel will burn, (known as ignition delay) sometimes engines work better with a long delay, (a slower & more efficient burn)this will work with a lower cetane rated Diesel.