[David70]

Originally Posted by RockCrusher

Techron does survive combustion. During combustion it is heated to its vapor phase then when as a vapor it comes into contact with cooler combustion surfaces reverts back to its liquid phase and in doing so works to cleanse the surfaces it comes in contact with.

This works in either port or direct injection engines.

How it works in direct injection engines is the DI engine is designed (using variable valve timing and opening the intake valve earlier) under some operating conditions to encourage some back flow of exhaust gases into the intake port past the opening intake valve(s). (Essentially exhaust gas recirculation without all the EGR hardware.) The purpose of this back flow is to slightly pollute the incoming air with exhaust gas to lower combustion temperature and reduce NOx emissions.

This works. NOx emissions are lower than they would be otherwise.

But the downside is the backward flow of exhaust gas results in some deposits collecting on the back of the intake valves but Techron now in vapor form in the exhaust gases Techron works to remove the deposits.

Unfortunately only Chevron gasoline comes treated with Techron.

However, Techron can be added to any gasoline that doesn't come with it.

As I have mentioned before for some time now my local BMW service has been adding a BMW labeled Techron additive to my car's gas tank -- this after putting in fresh oil during an oil/filter service -- or handing me a bottle of it when I settle up and collect the key to my car.

With the bottle I can use the Techron when I think it best. "Best" is I've been told is a few hundred miles prior to an oil/filter service.

Interesting, where did you get this information?

Techron goes through the combustion process unburned, is vaporized, intake valve is left open, vapor is sent back into the intake (assuming exhaust and intake valves are left open some amount), it turns back into a liquid and cleans the valves? Then unburned Techron is sent out the exhaust?

The purpose of this back flow is to slightly pollute the incoming air with exhaust gas to lower combustion temperature and reduce NOx emissions.

Pollute the incoming air with exhaust gas to lower the combustion temperature? Can't see a time when exhaust gas is lower than the incoming air. Exhaust manifolds get up to 1200 degrees.

I've never used Techron in my daily drivers (Chevron isn't here and I don't spend the money on bottles of it). Lots of claims, people say I need Top Tier, Techron, Shell, whatever and I am interested in seeing some proof, mainly because I haven't had a problem that I think a detergent could solve and claims are simple to make, hard to believe without proof.

The never ending belief that Shell is needed is interesting, I'll believe it when I see something from an independent company.

[TurtleBoy]

There have been quite a few studies/papers/articles on the benefits of Top Tier and additives in general. I would think anyone interested can find them with some searching.

[Gemini562]

I used to think any gas was fine as long as the octane was right...