mpg & sea foam??

[1987ss]

my 99 tahoe gets an average of 11 mpg and i changed,plugs ac delco,cap & rotor, wires,oil & air filter.. i was told but a buddy to add sea foam to tank and some trew vaccuum to break booster? any other suggestions? Thanks

[maxwedge]

Do it, no harm, may help but don't get your hopes up.

[1987ss]

is 11 mpg average?

[maxwedge]

Stop and start in cold weather depending on driving habits, could be.

[1987ss]

would you add it like this? http://members.nuvox.net/~on.roz/cars/z28/seafoam.html

[maxwedge]

I would not add anything to the oil. Fuel tank, throttle body ok, thru the vacuum ok.

[1987ss]

thanks