Have seen about a 10% drop in fuel economy from my car lately, even on long (>200 mile) journeys. Probably should give it an oil and filter change, and check the tyre pressures, but have always been curious about this stuff. I was under the impression there is some detergent in fuel anyway? Anyone know if it actually does anything?

tyre pressures can make a big difference, filter change too, plus check your plugs don’t need changing.

Diesel I assume. If so most mpg drop during the winter for various factors. Have a quick search on Google for the reasons why.

We’ve got two cars with the same diesel engine. Was was run for 6 months with Millers diesel additive and it cleared up the injector noise. Was laid up for 3 years and when we fired it up again it made me realise just how much the performance of the other car has dropped off so I have stated using millers in that too and it’s definitely reduced the soot that I can see in the headlights of cars behind when I boot it.

Another option is a tank of the higher grade ever now and then but as I have the millers I stick to that for now.

If you want clean the fuel system and injectors have a search for BG244 and its reviews.

Cold weather alone can knock your economy. Every moving part is stiffer/tighter due to thicker lube and harder seals etc. Then they all take longer to warm up and loosen off, using more fuel to do so 😉

In 20 years I’ve only ever seen people in the motor trade use these kind of thing too increase a service bill!!! Cold weather/air filter/ tire pressures all make a difference and non of these “cleaners” can be used on a new ish high pressure diesel with a particle filter etc due possible damage.
I was always told these diesel cleaner main 95% ingreadient is ether/petrol!!!

I was just going to say I am pretty sure the Millers is petrol with something to make it brown.

tyre pressures – 5mpg easily if they are very low
engine oil – never neglect its the engines blood.
winter – less mpg due to warm up cycles and heavier load from electrical system

Forget it – service the goddam car. Is a machine with a service interval look after the thing and itll stand you well , neglect it and it will let you down .

First question i ask when friends come to me with car issues – when was it last serviced … Usually get – whassat then.

Thanks all – not due a service yet, but might treat the old girl to a drop of oil and some new filters anyway!

Not due a service on milage or time ? And your not doing the stupid long service plan are you? ( unless your milage is all long motorway cruising miles that is)

I used to use Redex directly into the carb yonks ago in old (70s / 80s) engines, shocking how much crap it (appeared to?) shift. Thing is though, if you’re using an additive in your fuel to loosen crap, where’s that crap going to go?

Was laid up for 3 years and when we fired it up again it made me realise just how much the performance of the other car has dropped off

Fuel goes off over time, if you’d drained the tank and refilled it you’d most likely have seen the same / better results.

+1 BG244 for cleaning.

Millers is widely available and many e-net forums regard it as a good product. In my case gave 2-3mpg extra and engine works softer.

Archoil AR6xxxx are new kids on the block, *Stagecoach* use these type of nano additives to improve their fleet mpg.

Be careful with engines that have positive crankcase pressure. I put some injector cleaner through my old Volvo 2.4 petrol engine, which did a lovely job of de-coking, only for it to burn stupid amounts of oil until it carboned up again.