Q. about '98 ford ranger drop in gas mileage.?

The vacuum or fuel lines maybe possible failures and easily found with a gauge. With that many miles you should check your crank and cam triggers, also make sure your maf sensor is clean and your egr is working properly. Last but not least if your timing belt hasn't been changed in over 60,000 miles you need to change it. Any of these would set an engine light and after so long kick the computer into limp home mode letting the engine run but killing your mileage.

Normally the check engine light will give some clues to what's wrong but since you've ignored it, it's kind of hard to figure what it is... but a scan at the zone would be my first recomendation.

But I'd check to make sure as someone said, it wasn't stolen in this date and time...

Also I'd check to see if the exhaust has a real gas smell... if you've worked on them before, pulling the plugs and reading them should give you some sort of idea of how the engine is running.

I've seen the fuel pressure regulators bust, send gobs of fuel and the car take it with no real issues except a higher oil level than normal.

The vac leak is a good one but the car will only adjust to a point and then stop.. it will eat more gas but not a full drop like that.

I think first maybe a Ford locking gas cap (I find the caps bought elsewhere have a habit of not sealing correct and causing a MIL light issue) to verify it's being burnt

Might have a leak on the fuel system - maybe perrished pipes etc. Have the engine run and follow the fuel lines from the tank to the engine - you should see a fuel leak fairly easy. Be sure to stay away from hot or moving parts with the engine running.

With this kind of mileage (200K) you can expect to replace some of the rubber hoses and pipes. Be sure to replace the hose clamps also.

I would go to your local auto parts store. Most of the time they can pull a code from your ecm.(The computer) And go from there. O2's can wear out. Respond slow. Fuel mixture can also be efected by the computer's engine temp sensor. Not the one that runs the guage or light. If it reads alittle cold than what it really is it will run a little rich. I would at least have the codes pulled from the computer. That will tell for shure where to start!! Ecm's also have memory so if the light happens to be off a code still can be pulle. good luck

I would suggest checking your air filters, if your air filters in the airbox are dirty it will decrease your gas mileage the air going into your fuel plenium makes a big difference in gas milage. You can purchase a haynes repair manual at most auto parts stores, for almost all years of cars and trucks, they save you alot of hassles and answer alot of questions, hope that helps you.

have you done a tune up on it. might try that if you have not. if you have get the check engine light checked out might be a sensor mabe the oxygen sensor is bad. this would cause it to burn alot of gas.

Have you ever thought that maybe someone just siphoned your gas. Just a thought, happened to me try a locking gas cap.