Re: Redex - Is it any use.
redex is 95% kerosene and 5% ATF.
kerosene has been used to clean engines for decades. its the same stuff they use in engine flush and many other cleaning products. you can buy kerosene very cheaply, when you see how cheap it makes redex seem like a rip off.
in terms of using kerosene as a fuel additive, it is very ineffective as a cleaner. the recommeneded quantities are so small and it is only in contact with the inlet valve for a millisecond and the exhaust valve never sees any because it is burnt first. injectors dont really get dirty so cleaning them is useless. look at injectors after 100k and they're always spotless.
the best way to use kerosene as a cleaner is by pouring it in the sparkplug holes then turning the engine over for 5mins. this was recommended on the back of the redex bottle in the past, but they dont mention it anymore. while this method is far more effective, it doesnt really do much.
modern engines dont need to be cleaned. in the past engines would get coked up with carbon deposits, that doesnt happen any more. if you work on 100k+ enignes these days you see they are very clean, even the valves. yes they have a light coating of carbon, but it doesnt have any impact on compression so it isnt an issue.
using kerosene as a cleaner is outdated, using it as a fuel additive has never worked, but its still a good seller so the shelves wont be saying goodbye to redex and other similar products for a long time.
it does have 1 use, it gets your emissions down for an MOT. its also great for 2 stroke engines because they do still get coked up.