I always get gas at the same station. This last tank, with a little bit of a canyon run included, I got 17.7 mpg on average. I think it's pretty much something I'm going to have to live with untill I can get a manual tranny and have enough money to get the entire engine checked out just for good measure.

 

I would never use any of these additives in my vehicles. NEVER.

 

I have used Sea Foam in several vehicles without any ill effects. Why did you let it sit in the vacuum line for 5 minutes? From what I remember when I did my WRX, I pulled the brake booster vac line and added half a can of Sea Foam while the engine was running. I would add a small amount and as the engine would nearly stall I would rev it slightly and then add some more.

It made a ton of smoke, which it should. You need to keep runnign the car until all of that white smoke is gone. My MPG actually went up. My car had about 25K on the clock at that point.

Sea Foam is the exact same thing as Subaru Top End cleaner. This is what your dealer would use around 30K to clean your valves and top end of the engine. They just charge a whole lot more.

 

I let it sit because thats what everyone else suggested doing

 

As I posted a while back, the brake booster is definitely not the vacuum line to use; two mechanics I have spoken to say this will only clean half of the engine. The best line is the "vac head" line which recirculates from the BOV just below the intercooler. Obviously on a non-turbo engine you must use a different line, but the idea is to use a line that is a direct intake to the engine's breathing, not an auxilliary line that is rarely under vacuum (brake booster).

 

Now that a think about it, I must have used the BOV line. I distinctly remember my squeeze bottle getting permanently mis-shapen from all of the vacuum. Plus I remember asking someone if it was okay to run the car with that line off and then realizing that it's not like it was under boost at the time.