Gas cap???

[grc1]

Hi, Just curius, will driving without a gas cap affect gas milage??

97 geo tracker v16 4x4 auto

[cmays03]

I know on the newer vehicles( ie chevy ford dodge) if the gas cap is not tight it will set the check engine light off. so i would say that it could effect it some how. something to do with pressure. I know when you change the fuel filter they say to take the gas cap off to relieve pressure.

[Milwaukee]

yes

why gas go vapor

like you notice if you left cap off let say you fill tank really full but 1 month with no cap you would notice you lose 1 to 3 gals.

[TheZuke!]

If you don't have a locking gas cap your MPG's will go way down,
when someone uses an Oklahoma Credit Card (siphon hose) on
your tank!

I really don't mean to insult Okies/Sooners, some are really
nice folks (except my drill Sargent at Ft. Sill ).

Seriously, a leaking/missing gas cap on a Fuel Injected vehicle
is NOT A GOOD THING(TM). It will mess up your emissions
computer, likely (certainly?) reducing your MPG.