I can vouch for the Techron Concentrate Plus. I'm currently in the states and this is by far the most recommended fuel additive that actually works. I use it frequently on my VW and it helps improve the mileage by a noticeable amount. I use a bottle every ~2000km.

Just pour in a bottle of the Techron when your fuel tank is almost empty then proceed to refuel your car.

I've tried many other brands but none works as well as this TCP. A new one that just came out here is the Royal Purple Max Clean but the verdict is still out there. Tried a bottle of it but didn't notice as big of a difference as with the Techron.

A definite increase in MPG. (I'm in the states and that's what they use ) I used to travel the same route almost every weekend and it's about an hour's drive for me. Before using Techron I got about 28MPG at an average of 75MPH. After using it my car managed to get ~31MPG. One thing though, the effect does not last forever. I use a bottle every few thousand km.

I do have to say this though, initially my car had some misfiring issue that was giving me a headache (changed spark plugs, coilpacks etc with no result) and surprisingly this Techron managed to temporarily stop the misfiring issue that I had. Eventually I found out the real cause for the misfiring and got it fixed permanently

No worries! Hope it works out well for you

Get a funnel that can fit into the gas tank. My friend has a Fiesta and I had to get one for her. Works though.

I'm currently in the states. Quite impossible for me to help you out.

My car is using a DI engine. Technically it will not be able to clean the intake valves because of the nature of direct injection. But it still helps in other ways for my car.

You used a funnel and it didn't work? Get one that's suitable for cars and not just any normal funnel.

Edit: This is something like the one I got for my friend.



This post has been edited by pengster: Jul 23 2014, 03:17 PM

Yeah it shouldn't be too expensive.

He has a Fiesta which has the capless fuel tank thingy that makes things difficult

The only real way to get rid of the carbon deposit on our DI engines is to either get it manually cleaned (which is what I did) or do an Italian tune up.

It might help a bit but it won't get rid of the carbon buildup. The fuel does not go through the intake valves in DI engines. For non DI engines you're right, the fuel will hit the intake valves hence cleaning it if the fuel has detergent in it or if an additive is used in the fuel.

Yup, similar experience here. I only pump the equivalent of RON98 here and even then there's still a noticeable improvement.

I had it manually cleaned. The workshop guys removed the intake manifold and soaked the valves in a solution for a couple of hours before scrubbing all the carbon out. BMW has their own procedure for their DI engines which is called walnut blasting. It seems to be a normal procedure for them to have their valves blasted once in a while.

For reference, take a look at how bad the carbon buildup was on my car



This post has been edited by pengster: Jul 24 2014, 03:26 PM

Yup it's pretty bad. But its common among the VW/Audi 2.0TFSI engines and on the BMW DI engines. Doing a full carbon cleaning once in a while is common practice for owners here. But, an italian tune up every now and then helps keep our valves clean

Here's one of the valves after cleaning:

Mine costs USD400. 4 hours of labor at $100/hour.

Btw my car was at ~127,000 miles at that time. So that's more than 200,000km.