I recently bought a 1990 Ranger, automatic, 2.9 liter V6 with AC. I had the fuel system serviced including a new fuel pump, new fuel pressure regulator (I'm a newbie so sorry if I'm using the wrong terms), new air intake temp sensor. That made the tranny shift a lot more smoothly. Also recently replaced the valve cover gaskets. Wow that was fun. I'm still getting 10 MPG like I was before I did all of this. No smoke from the exhaust or engine, idles smoothly at 600-700 RPM, starts right up, runs and accelerates beautifully. Transmission is in good shape. She really runs well. I do a lot of city driving but 10 MPG is still way lower than what I expected. Where do I go from here?

Thanks!

Ron

 

What rear gear? 4x2 or 4x4?
Are the tires stock size or larger throwing the speedometer and odometer off?

Winter gas and colder temps drop mpg by a few but 10 is bad. I would start by making sure the odometer is accurate.

 

2 x 4, stock tires and stock everything. I'm pretty sure the odometer is accurate but I'll check it. Is there a simple way to check it that I'm not aware of or do I just use another vehicle to pace out ten miles and see if they match? Speedometer should be good because I'm not outrunning or delaying anyone in traffic but I'll check that the same way. Thanks!

 

60 mph = 1 mile a minute........Check it over one of those speedo check areas on the freeway while on cruise at 60mph. Or use a GPS to check against speedometer........I had this problem running 31 x 10.50s instead of stock tires on my Ranger, my odometer read 14% low giving me 13 mpg when the real mpg was more like 17-18........Another thing in your case would be to look for something dragging you down like sticking brake caliper, E-brake etc.

 

Any Federal and most state highways have mile markers. Just find a nice long stretch.

 

Try replacing your sparkplugs and wires. Unless that has been done within the last few years that will get you a few more miles per gallon.

 

And make sure your tune up parts are all Motorcraft or OE spec Autolite.

 

I agree with Dave's suggestion to see if something is providing roll resistance. In addition to his suggestion of a sticking brake caliper or shoe (or a binding ebrake cable) it might be a good idea to check wheel bearings. A wheel bearing that is torqued too tight will cause roll resistance and excessive bearing wear. Don't forget to make sure that all tires are properly inflated. An inflation pressure of 10% above the manufacturer's recommendation is ok, especially if you do highway driving. (35 psi instead of 32 psi) One more thing to check might be the catalytic converter. If one gets plugged mileage and performance can really suffer. This could be a problem even with the smooth idle because it does not become a problem until higher volume air and exhaust flow are required at driving speeds. Catalytic converters can plug for no reason at all but the use of oil and fuel addatives can make the little ***** in the converters sticky too.

How are you driving the truck? Do you come away from stop signs as though you had an egg under the gas pedal. To blazes with all those jack rabbit throttle punchers who drag race away from every stop light or stop sign. Also, when you approach an intersection where you must stop or where you may get caught by a red light, do you save your brakes and some gas by coming off the throttle earlier and letting the vehicle free wheel some of the distance to the stop. Driver habits are clearly the biggest factor in fuel consumption.

With a Windstar van that I drove before buying my pickup and before the kids were out of the nest, I observed that driving 5 mph above the Interstate speed limit dropped my mpg by about 14% and driving 5 mph under the limit improved mileage by another 14%. (21 mpg at 65, 18 mpg at 70 mph, and about 24 mpg at 60 mph). Town driving in the winter is going to be your worse mileage condition, but 10 mpg is really too low. I get 18 mpg in my '04 Ranger 2x2 with a 4.0 Liter V6 and a tow package, (mix of town and highway) and I am not very happy with that. I must admit that careful driving and controlling speed in the pickup DOES NOT seem to make the difference that it did in the Windstar van, but I have not checked closely. (Had to give up my wife's old car for daily commute (2000 Saturn SC1 that got 40 mpg with 200K plus miles) because son's 95 Probe got wiped out at college. He needed another car so he got the Saturn and my Ranger became a daily driver instead of an occasional driver.)

Good luck! Tell us if you find a solution.