Only 20K mile in my Geo I have everything original except the oil filter and exhost 90806 miles yeah original plugs and the air filter really is not very dirty.
These head winds are killing my mileage with this tank - only getting about 43 so far in the xB. Another interesting thing is by filling the tank right up to the filler spout I get about 2.5 gallons before the gauge drops to the full mark.
I heard that if you fill up to the spout that the fuel just evaporates and it's pretty much wasted. This never really amde any sense to me cause your fuel cap is pressure tested whenever to take it for emissions here in Maryland. If the tank was air tight wouldn't that keep the fuel from evaporating?
fuel evaporates thru the charcal canister, and continued over filling will saturate the canister, or so I've been told, if you look in your shop manule under "evapritive emission controles" it will show the routing of the tubes that let vapors go to that canister, in theory the engine sucks them out of that canister and burns them... not sure how it controles that.
I've heard that about the charcoal canister too. But I've also heard that as long as you drive a few miles right away the canister saturation isn't really an issue. I've been filling my vehicles all the way to the top since I started driving. This includes vehicles from the 70's, 80's, 90's, and 00's without any problems with the charcoal canister to my knowledge.
Horsepower is how hard you hit the wall, torque is how much of the wall you take with you.
Exactally - Soon as you start driving the tank level drops and there is no problem - I also have a fuel pump in my xB that depresurized the gas tank after about 5 hours after engine shutdown to reduce tank pressure. All the vapors in the canister get sucked into the engine when you start driving. Usually the gas level will drop when it gets this full in a few seconds as a trapped air bubble breaks loose but not in this tank.
Started my new tank today. 69.52 on the way to work, 45F dry roads and 61.57 on the drive home, 65F WET roads and rain. RT = 65.3 MPG. Rain, Rain go away, come again some other day when I am not driving.
In the immortal words of Pink Floyd.... All in all it's just another brick in the wall.