worse gas mileage after seafoam

[phil_the_thrill]

has anyone ran seafoam in their gas tank? i did about a month ago and i heard that it was supposed to increase gas mileage but i've noticed a definite 1-2 mpg decrease. has anyone had the same problem??? maybe i need to change my fuel filter. what do you guys think?

 

[97vertstang]

i gained around 1-2mpg. thats a good idea to change ur fuel filter, i just changed mine yesterday and car started up better.