gas is going by fast... 20 dollars would get me 30 miles and thats it.. What would you think the problem is? Gas Filter?

engine light on? could be gas is leaking past your piston rings and going into your oil there for loosing gas and gaining oil lol, how does your oil look through your oil fill? or can you smell gas coming out of the exhaust? if so then it could be o2 sensors, mass air flow sensor, or some type fuel/air sensor

Or it needs a tune up. Nothing was ever mentioned about oil levels so I'm confused as to where you're going.

All of those are symptoms to the lack of fuel mileage as well. Do not forget to clean TPS, have crank sensor checked, EGR valve, also the Fuel pressure regulator. And have the exhaust system checked for leaks. A bad Catalytic converter will do it as well.

It's carbureted.... it doesn't have a TPS or a crank sensor or a fuel pressure regulator, bad egr would have the guy asking about the engine running rough, not bad fuel mileage. Exhaust leaks have absolutely zero to do with gas mileage, and a bad cat would either do nothing at all or it would create back pressure preventing higher engine rpms.... even if it was fuel injected the tps can't be cleaned, the crank sensor would cause the engine to not have any spark..... fuel pressure regulator would be the only possibility in what you said....New this question is 6 months old.