i put a full bottle into my tank and filled it up with gas then went driving on the highway for three hours. This was on a 6thgen with 55k and there was no noticable differance. No smoke was visible either. I had a more noticable change going from mobile1 5w30 to 0w20.

 

Ways to use seafoam. I've done them all without problems what so ever...

-pour some in the gas tank
-spray in TB with a spray bottle with motor on
-spray into the brake booster vacuum line with a spraybottle with motor on
-pour some into crackcase
-pour small amount into cylinders after removing spark plugs and let it "marinate"... motor off of course
-dip brush into seafoam and scrub the inside of your muffler before shows

 

Make sure you change the oil after running it through your motor. Also a good idea to change the spark plugs. If you want to change to synthetic oil, after this is the time to do it.

 

Yea you only need 1 bottle. Someone has said it already just poor 1/3 into your crankcase after you do your pcv valve and gas tank. After you have it all in your car go for a spirited run with the seafoam still in the gas, crankcase. After your spirited run just change your oil and just leave the stuff in your gas tank.

 

for a 4th gen, whrs the brake booster line?
thanks