petrol additives
 

Hi, I have a 1998 V70 with 141,000 on the clock. I have "Googled" reviews on petrol additives but in the end poured in a bottle of Wynns additive; not really expecting to notice any difference.I must say that tickover was improved and the engine smoother. I must add that I have no connection with Wynns in any way shape or form. I am going to throw anther bottle in shortly.Cost about €6.00.

Additives
 

If you can get Shell V Power high octane, you don't need additives. In Europe I always get the highest octane fuel... plain French/Spanish cheapest supermarket petrol results in slight spluttering at speeds over 110 kph as the computer doesn't like it. At 130 kph, you'd think the there's something very wrong with the engine.

Honest John always recommends V Power but it costs another 8-10p/litre = £6 for a tank, which is what a whole can/bottle of additive costs, when you only are advised to put a little in with each tankful.

Hi Clogs,
I don't remember seeing a Shell garage here in southern spain. I believe that to make any improvement higher octaine petrol should be used all the time and that is expensive. I put a bottle of Wynns in the tank every 6 months and I think there is a general improvement.

Any high octane fuel will do the job.
I find that if your just pottering about local there's no discernible difference between regular and premium petrol.
But as soon as your going on the motorways/Autovias above 70-80mph you start to feel the difference with turbocharged engines in particular.

The answers here all related to improving performance. I use regular fuel in engines which call for it but fill with premium before a trip to the mountains / rolling hills where I know I'm going to "get on it".

I figure the computer aided gadgetry will want to advance my timing here and there and I don't want to make the engine knock or have said gadgetry retard the spark.

Twice a year I add a 20 oz. (their large size) bottle of Chevron Techron Concentrate before a stint of local driving.
The knowledgeable ones on the oil board I read say the PEA (don't ask, I forget) cleans off the injector tips upon shutdown.
It is the stuff I see on parts department shelves in posh dealerships.

I have used Wynns or STP additive all my motoring life since 1964.....i actually swear by it hence it`s use for my petrol engines.

Now for my Merc diesel i use Shell Nitro but with two stroke added.

2 Stroke Oil
Due to the pollution control measures of the EC diesel-oil is nearly sulphur free and contains up to 5% of bio-diesel. Sulphur has the property to grease the high pressure injection pump and the injectors. Without sulphur, the reduced greasing property of the new diesel has already shown negativ impacts on the long-term stability of the injectors and the high pressure pump. The pump manufacturers have tried to react by lining the moving parts of the pumps with teflon or other suitable material. However, the long term stability is still not achieved as with the old (sulphor contained) diesel.
The engine-research centre of a well known German car manufacurer has conducted some long term tests of diesel additives to find out whether any one of them will have an impact on the long term reliability of the diesel engine components. This introduction to explain were my information comes from.
The results of this research: any diesel additive of any manufacturer presently on the market is not worth the money!
BUT: 2-stroke oil, which we use in our motor saws, lawn mower or in 2-stroke motor engines has shown to have an extreme positive impact on diesel engines, if such 2-stroke oil is added to the diesel in a homoeophatic dosis of 1:200. In practical terms: 0,300 litre of 2-stroke oil into the 70l diesel tank. The 2-stroke oil will be absorbed by the diesel (emulsion) and grease every moving part of the high pressure pump and the injectors.
Besides this, the 2-stroke oil will keep the diesel engine clean, as it burnes cleaner as the diesel itself.
In other words, the 2-stroke oil has a much lower ash-content as diesel, when burned. This proven fact delays the DPF (diesel particulate (soot) filter) to clogg, and the "burn free" process of the DPF will be much less.
One more information: in Germany we have to present our cars every 2 years to the TUV -Technical Supervision Organisation - who will check, amongs others, the pollution of petrol and diesel engines.
The measured cloud-factor of a diesel engine without use of 2-stroke oil has been 0,95.
The same factor with the use of 2-stroke oil has been 0,47 - reduction of nearly half of the soot particles.
Besides this, the use of 2-stroke oil in the diesel will increase the milage by 3-5%.


and more :-
You may all know that Mercedes Benz have conducted in 2007 a long distance reliability test with a number of Mercedes E-Class 320 cdi from Paris to Beijing. Due to the fact that the diesel quality in East European Countries, Russia and China does not meet the DIN requirements, and Mercedes did not want to take the risk of their engines to flopp due to lousy fuel, the total tour has been accompanied by diesel tanks to re-fuel the E-Class cdi's. Selected members of the Mercedes clientele could apply to participate in selected parts of this test-tour, and advocats and notaries had to certify the correctness of this long term reliability test.
Although Mercedes does not like it published or made public, it is a fact that the diesel-fuel used for this test did contain 2-stroke oil to grease the high pressure pump components and to keep the engines clean during this marathon.
Why our car manufacturers do not officially allow the homoeophatic addition of 2-stroke oil to the diesel fuel has many reasons, mostly of legal nature. Besides this, which car manufacturer has any interest in excessive reliability of their engines? Their repair shops will have great problems.
Meanwhile the "2-stroke-oil to diesel" issue has attracted the interest of a number of Universities in Germany, as this 2-stroke oil has shown to have amazing poperties if added in a small dosis to diesel fuel (1:200), especially the positive impact on air pollution, reduced fuel consumption and improved long term reliability of the diesel engine. The pro and con discussions will go on for a while. But as soon as an accademic report has been published by one of our Universities, this will change very fast.
By the way: all car manufacturers reject the addition of any fuel "additive" in their cars, and warn that guarantee MAY be affected. Nobody says, that guarantee WILL be rejected. 2-stroke oil in its properties is not an additive, as you add oil to oil if you "dope" you fuel with a dosis of 2-stroke oil. The dosis of 2-stroke oil in your diesel-fuel is very difficult to analyse, as every (chemical) analysis has the main function to identify substances which are harmful. But 2-stroke oil has proven not to be harmful at all, on the contrary!

I did wonder when this thread popped up originally what effect the location of the poster has on the answer to the question of additives, Jack is from Spain, byotox from Scotland, Clogs I presume is from Canterbury England not New Zealand, Georgandkira from the USA and now 960kg from Germany.
We have in previous threads discussed the different octane rating systems of the US and the UK and Europe, and how that affects 'fuel quality', and there's always a debate to be had about differing fuel quality in the UK between oil company brands and supermarket fuel. The UK brand debate usually comes down to opinions on whether the fuel does or does not have beneficial additives in it to help with fuel system cleanliness etc. Personally I've never felt the need to use an additive but if it works for you that's great and thanks for sharing. In my own experience I found premium fuel to improve the mpg figures of my 940 enough to justify the price hike but it made no significant difference on my V70, I'd guess that the only way to really tell is to use whatever potion you want, keep a check on mpg, smoke etc and go with the best result.

Fuel Additives
 

The more expensive high octane fuel with additives is say 10p/litre more. My 1999 V70 T5 does around 8,000 miles a year, at 28mpg (6.2miles/litre) and so uses about 1290 litres, costing an extra £129 p.a. to keep the engine cleaner than using supermarket cheap unleaded petrol. You pay your money and make your choice. Using Wynns at £5-6 good for let's say 258 litres, I would spend £25-30 on injector additive, but this doesn't help with better fuel economy because of higher octane fuel which adds about 1 mpg or 0.22m/litre, which is equivalent to a fuel saving of about 56 litres = £65-70.

Summary - with additive cost and extra cheap fuel (27 mpg instead of 28 mpg) = £90-100 p.a. (25to30+65to70) or Shell V Power £129 extra fuel costs, smooth engine running and no messing about.