Fuel additive..better mpg??

[ScottinMA]

I had a trip to VT this past week in my wife's Passat wagon. Since it was cold I purchased some STP gas treatment (their label of dry gas) and tried to put it into the tank at a gas station just before climbing up to SugarBush. The neck of the bottle was too short to get past the interior clip in the tank so I only got a little in. I then noticed that on the climb up the mountain the engine would seem to miss. I assumed it was my size 13 boots accidentally hitting the brake pedal when pushing down on the throttle and forgot about the symptoms. On the way back I used a stick to push back the clip and unloaded the whole bottle into a full tank of gas. Started down Rte 89 and the car started bucking and misfiring. The check engine light went on and it was one hell of a ride for awhile. I kept stopping for gas and topping it off with the best premium blend and after about 8 hours (we also got caught up in that 50 car pile up on Rte 93 in NH that made national news) the missing decreased and eventually stopped altogether. I was putting in new premium gas about every 40 to 80 miles to dilute the "gas treatment" and we ultimately made it home alive without and damage to the exterior to the car. Fortunately (I think), the next morning I filled the tank again with premium and the check engine light went off. So hopefully I'm in the clear but I NEVER by the stuff again!

[Joe_Black]

I've got a bridge you might be interested in.

[Hotsauce]

Since the air/fuel ratio is controled by the computer, the only way to get better mileage is from more timing. This will only occur if an additive can supress knock and detonation enough for the knock sensor not see any knock. When this happens the computer will allow more advance.

All the additives that do this that I'm aware of are highly carcinogenic.

John C.

[VehiGAZ]

There are no miracles-in-a-can, guys. If there were, Mobil, Sunoco, and everyone else would mix it in with their pump gas.

[Ruflyf]

Always be skeptical of products that say will increase your _______ "up to __%. If it was a legit product it would say " will increase your ____ a minimum of ___%