Petrol Additives

[Splatt]

Many years ago there used to be a fashion for owners putting additives in the petrol for various reasons, be it knock reduction, to raise the octane ? or as upper cylinder lubricant. I remember fogging out the neighbourhood by pouring Redex into the carburettor in order to de-coke my old banger. However we have been well told that that with modern engines and fuels this is not only unnecessary but positively deleterious. I was therefore somewhat surprised to note on my invoice for the first A service just done :-Z0502 Fuel Additive £11.50 +VAT>
Anyone else had this ? is it something magic MB stick in to make it go better or smell nice ?

 

[jibcl500]

Read your handbook, it states MB dont approve of fuel additives.

jib

 

[verytalldave]

Fuel and oils have come a long way since the 1960's and 70's when it was popular to use such additives as Redex and adding Molyslip and STP to the oil. Nowadays Oils and Fuels are refined and produced to much higher standards to a point when any addition could have a counterproductive and even a detrimental effect. Also engines and gearbox materials are far better nowadays and can withstand greater pressures than 40 years ago. When was the last time you saw a car with a rear window sticker that reads "Running in - Please Pass"? I dare say many drivers under the age of about 30-40 have NEVER ever seen one.
Use good quality fuels and lubricants. Thats all your car needs. Despite what advertisers may try to tell you.

 

[Splatt]

Read your handbook, it states MB dont approve of fuel additives.

jib

This was put in by the areas premier main MB dealership and it is their service invoice I am quoting.

 

[verytalldave]

Surely the easiest thing to do is ask the garage that did the service. I have just tried to find out exactly what "Z0502 Fuel Additive" is with no luck whatsoever.
Let us know what their reply is please. It will be interesting to find out its function. Thanks in advance.

 

[Splatt]

If this is as strange as you suggest I will certainly take it up with them. I also need to ask them how 5 litres of oil at £12.00 comes to £66

 

[David Nock]

Gosh that invoice must have been made up manually! I'd watch that place!

 

[Splatt]

Ok, had a word with them, and they confirm they always put a detergent additive in to clean the fuel lines and injectors. I think what they use is this
http://www.forteuk.co.uk/Specialist_Injector.htm. Not totally kosher but I must confess the car is running smoother and seems the better for it.
Also it seems it is only available to the trade.

 

[David Nock]

What about the 5 times 12 is 66 lark?

 

[Blobcat]

Ok, had a word with them, and they confirm they always put a detergent additive in to clean the fuel lines and injectors. I think what they use is this
http://www.forteuk.co.uk/Specialist_Injector.htm. Not totally kosher but I must confess the car is running smoother and seems the better for it.
Also it seems it is only available to the trade.

It is an injector cleaner & it is a good idea, as for the other fuel & oil additives available I wouldn't use them in my cars/bikes.

 

[philharve]

Redex petrol additive

Hi All

Interesting thread with opposing views.

I put a measure of Redex into my petrol tank every time I fill up, about every 5 - 6 weeks. What's more I use Shell V-Power fuel which most would say would make the addition of Redex redundant.

I have run my C230K on this mix for several years and I have had the opportunity to run only on V-Power and with a shot of Redex. The difference is dramatic. The engine feels smoothly, quieter and develops a significant and worthwhile increase in power, doubtless as a result of the higher octane.

About 2 and a bit years ago I had to have the cylinder head gasket replaced because the engine had begun to leak coolant. The mileage then was 135,000 miles so I had the cylinder head totally overhauled because wear was apparent in its components. I saw the cylinder head before it went for the overhaul and my indie asked me to call into his garage to view the cylinders. I thought it a slightly odd request unless he had detected more problems and wanted to talk to me about them. I was wrong. Instead he asked me what fuel I used. I admitted to the mix I still use today. He said he had rarely seen an engine in such clean condition. There was virtually no carbon build up and the honing marks were still clearly visible on the cylinder walls. He took a set of photos of the engine and refurbished cylinder head which I duly published on this forum.

If the use of Redex to V-Power, or any modern fuel, is detrimental/unnecessary for a modern engine then I would have to strongly disagree. My experience would seem to indicate that it keeps the engine clean, well lubricated, efficient, responsive, quiet, smoother and the mix possesses a quality rather like that of rocket fuel.

Regards

Phil

 

[s5tuart]

I think that Shell will make the same claims for V-Power alone. They say it has additives and detergents.
http://www.shell.us/motorist/shell-...ml?gclid=COnrwb-zsscCFeSstAodXKwHVg&gclsrc=ds

 

[philharve]

Hi s5tuart

Yes, they do make that claim but I have noticed that when Redex is added to V-Power the qualities claimed for it by Shell are apparently enhanced. The difference is quite marked yet if V-Power is as good as it is claimed, adding Redex should have negligible effect. However, experience has taught me that there are still gains to be had.

I have not encountered any adverse effects using this particular mix. I wonder if we have any forum members who are chemical engineers and maybe able to shed light on this matter.

Regards

Phil

 

[television]

Hi s5tuart

Yes, they do make that claim but I have noticed that when Redex is added to V-Power the qualities claimed for it by Shell are apparently enhanced. The difference is quite marked yet if V-Power is as good as it is claimed, adding Redex should have negligible effect. However, experience has taught me that there are still gains to be had.

I have not encountered any adverse effects using this particular mix. I wonder if we have any forum members who are chemical engineers and maybe able to shed light on this matter.

Regards

Phil

It can be detrimental to use a higher octane rating than the engine can use, as a standard engine shall we say cannot burn it all, maybe that is why the head gasket failed.

There is much information out there on this, and many members who have tried 98 ron fuel in a standard engine have found the fuel consumption to be worse than using 95ron. I have tried it once or twice and the actual fuel consumption was below normal, test over a 500 mile run with 98 one way and 95 the other.

It requires a compression ratio over a certain figure to be able to make use of the higher octane, and with very high compression engines you have to use 98 ron, or drive avoiding any hard acceleration.

 

[s5tuart]

I have no axe to grind either way, but when I was frequently driving down to Portugal my Indie "said" they had adjusted the octane rating on Star to take account of the poorer quality of fuel over there. AFAIK 97 or 98 RON just isn't available over there.
So from what I'm told. the car can be tweaked to accept various types of fuel and perhaps Phils car is tweaked (accidentally...) to like the Redex mix better.

 

[television]

I have no axe to grind either way, but when I was frequently driving down to Portugal my Indie "said" they had adjusted the octane rating on Star to take account of the poorer quality of fuel over there. AFAIK 97 or 98 RON just isn't available over there.
So from what I'm told. the car can be tweaked to accept various types of fuel and perhaps Phils car is tweaked (accidentally...) to like the Redex mix better.

Redex is one thing and used to be used for keeping the engine clean, no harm in that at all, the 98 ron fuel is a total waste of money as the engine cannot burn it all, sure you can retard some engines to allow you to use lower octane levels. Engines that have anti knock sensors auto adjust to a fair degree.

 

[gizze]

I bought 2.0T A4 Avant the other week, needed something to replace the ML I stupidly sold.

When I got it there was a slightly, and I do mean slightly, rough idle.
I read up and realised these cars tend to coke up and they can do with a good clean out every once in a while, under acceleration you could also see a bit of smoke.

I did some research and kept coming across two products...

http://www.powerenhancer.co.uk/shop...0-pro-petrol-cleaner-pea-concentrate-661.html

and...

http://www.powerenhancer.co.uk/shop.../bg-44k-petrol-fuel-system-cleaner-325ml.html

They are just down the road from me so went to see them and he said go with the AR6400, the only reason being is it is easier to pour in the tank.
I did, I filled up and within miles the car was smoke free and idling perfectly.

I have had enough cars where I have lost power and mpg using 95 that I would not even consider using it anymore, if the car is set up for 98 of course. Problem is it takes a couple of tankfulls to see the gains, the minute you dilute it and the octane drops below 98 again the knock sensors retard the timing once more.

My 335i was down over 40bhp running on 95 ron, proved on a rolling road.
I took it back to the tuners as I thought the map was lost, turns out my wife had filled up on the cheaper stuff. Very embarrassing!


The 2.0T says to use minimum of 98 ron, it says you can use 95 ron but you may experience poorer running, loss of power and lower mpg figures.

 

[philharve]

Hi All

Interesting replies!

I was shown the failed cylinder head gasket by my indie and it had failed at the thinnest point. If I recall correctly, the width of the gasket was barely 1/8" wide (rear, righthand corner, looking from the front of the car) and it was the coolant that was leaking. Actually, it took weeks for the coolant warning light came on. The leak was a dribble rather than a gusher. In a 13yr old Mercedes such a failure is not uncommon. My indie said he had seen this failure before and always at the same location.

My indie checked for traces of leaking from the cylinders and there were none. However, I take your point about higher octane ratings and possible engine damage. I thought my engine had knock sensing because it has never in its 15yr life exhibited rough running regardless of what I put in the tank.

Would a cap full (measure) of Redex really make that much difference in a tank containing 69ltr of a premium fuel?

Mileage? Mostly shortish journeys (10-15ml) returns 25mpg. During the relatively few long journeys (250ml) I have seen 38-40mpg with 'spirited' driving.

Has my Mercedes been 'tweaked'? I have owned the C230K (Auto) for 11 of the last 15yrs and I have not modified it. The original owner was an automotive designer/engineer and I did meet him. He made no mention of modifications to the engine but he did say the car, a retirement gift, was a 'special'. I understood this meant 'ticking boxes of required features' when he ordered the car.

Maybe I have just been lucky but my gut feeling is that my experience is typical and therefore repeatable. It is a very reliable car and the only time it let me down it was due to a dead Bosch battery. Cell failure at 4yrs! My indie replaced it for a third of the cost with a non-badged battery, which my indie assured me was a Bosch in plain clothes. I still use that battery today. The engine always fires up with enthusiasm at the first flick of the ignition key.

Regards

Phil

 

[Ben Longden]

Now.... where does this stand with MB?

Having said that... mine always puts in an injector cleaner.. About $12.

 

[television]

We know that a tank of 98 ron will clean things like petrol floats, and can have a similar effect on engine components, Redex can do no harm, though we do not get the troubles we used to get as the fuel has additives anyway and they are cleaner.