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99 Nissan Pathfinder losing gas?

Is there any reason that the gas mileage should go from 22 miles to 9 miles per gallon? How do i check if it is the gas gauge-I dont wont to run out of gas to find out! 153,000 miles-well taken care of tank read E after only 187 miles! Has done this the last 30 days. Any suggestions

You should know if it’s the gas gauge by how much gas you put in the tank. If gas gauge says empty, but it only takes 5 gallons then I’d suspect the gauge. You have filled it up haven’t you???

I refill at half full. sometimes it takes ten dollars, sometimes 18 or 19

Gee…so does mine…but that’s because of the fluctuating gas prices. How many GALLONS does it take…NOT the cost.

Have you kept up with basic “tuneup” maintenance?
With this mileage/age I would look at the distributor condition and timing.
Check tire inflation and alignment.
Replace thermostat if over 4 years old.
Proper oil viscosity - not too thick.

I Definately have kept up with Tune up, Transmissions, Winterizing / Summerizing, Oil Changes etc Oil is good, and I am having an alignment today just in case
Will have them look at thermostat (didn’t know that could affect mileage)and distributor just in case-thanks for the tip!

I would guess you know your car and you really have had a big reduction in mileage. Cold weather will reduce mileage, but not that much.

I would guess your 1999 car has a modern computer system that will trigger a CEL if it detects a problem. Have you had a CEL (Check Engine Light)? If so time to get it checked.

All kinds of things can cause that kind of mileage loss. A CEL error code could help point in the right direction.

DO YOU SMELL GAS? All the time? look under the car for puddles. If so you have a leak and it could be dangerous. If no leak, then check your actual gas mileage. You know you were getting 22 or so you say, which says to me you were actually checking. You may still be getting 20-22 and the guage is off.

Is there still a gas cap?

Do you notice a lot of black smoke out the back window and the car is running totally rotten? If so, there are quite a few things that could cause a loss of mpg and about the only way to find the problem is to do the hands on check the system. Possibilities are thermostat, throttle position sensor, engine temperature sensor, injectors-on and on. If you are “burning” all that gas then the car should be running very badly. Also the check engine light should be on.