Redex Engine Cleaner has, in one form or another, been around for a long time. It is a name that many older motorists will certainly recall and indeed their fathers before them. Historically, fuel additives like Redex have been used to combat the damaging effects to engines of using inferior fuels.
Here in Britain, we expect our automotive fuel to be of a high quality although this can vary between different brands. Some say, for example, that ‘supermarket’ petrol does not have the all the additional cleansing additives found in the often more expensive name brands.
Why Use Redex
During combustion, deposits build up and impair the function of a cars’ fuel injectors. This reduces economy, affects performance and costs money. So does the old adage that a shot of Redex at every fill-up will combat this issue still stand up?
Working with Redex, for the purposes of this trial we used a very low mileage Citroen C1 city car and a 2008 Ford Ka, volunteered by a neighbour, with almost 100k on the clock and in need of some TLC. Both cars run on petrol and have similar performance, which is about as scientific as this test gets.
You see, although this writer knows how cars work and loves to drive them, I have proved over the years that I am not the person you want to fix your motor. I don’t have the aptitude for it. I am to engine repairs what Cheetah, Tarzan’s simian mate, is to open heart surgery. Allow me to disassemble a part consisting of three individual pieces and when reassembled I would have one bit left over. I hope that clears that up.
The Three Month Redex Test
Although the Citroen usually gets Shell, for the purposes of this experiment we used a generic supermarket fuel in both cars. Both were run low on juice and filled, with a one small bottle of the product (image) added. We did this three times consecutively on each vehicle.
Now, both of us had a half-forgotten recollection that it was a good idea, having filled up, to give the car a goodly run at speed; so it was out onto the A419 for a blast.
The effect on the Citroen was seemingly minimal; the effect on the ageing Ka more marked. The tired engine blew exhaust smoke during the drive but how much this was down to the additive was unclear.
Over the following weeks we ran the cars through their usual routines and checked how they were running. The Citroen was checked with a Foxwell diagnostic scanner but since the original reading showed no operating issues, no revelations were revealed. I did not notice any marked improvement with the French car’s economy but I was able to convince myself that it seemed smoother in operation. Whether this was down to it passing out of its ‘running in’ cycle at about 15k miles makes it a moot point.
Thoughts On Redex
The Ka gave a more impressive result. Although it is periodically serviced the owner did find that the car was generally running more smoothly and he directly attributed it to the Redex.
Now, fuel additives haven’t really disappeared from our motor factors’ shelves but neither have they caught on in a way reminiscent of those days gone by. In my view modern cars, properly serviced and using premium fuel don’t need it; otherwise, I would suggest, manufacturers would recommend it. It is also important with any car under guarantee that the fine print of the warranty itself be examined for anything that excludes additives and the like. The Citroen document, for example, refers rather vaguely to ‘unsuitable fuels’. It’s a thought.
There does seem to be a case for a shot or to in the tank of older cars though, particularly those where attention to the servicing schedule have been less than thorough. The Ford Ka did seem to be a better runner.
Research on the use of fuel additives by motorists generally over time has never been conclusive it has to be said. Some users swear by them, others found them to have little or no effect. My summation would be that some additives do what they claim, but they should be tried and tested brands. Saving money by using a cheap additive that makes all sorts of wild claims could end in disaster. By choosing a fuel additive like Redex that says it will clean the fuel injectors and aid smoother, more efficient running you could well notice an improvement, but it’s got to be a name you can trust; that much is proved historically. Geoff Maxted