Efficient Fuel Mileage 4.0 OHV

[Angry Possum]

My Ranger gets around 11 mpg city. Highway maybe 18 or less. Is this normal for a recently tuned up 4.0 V6. If so, how does one make it more efficient? Inflate the tires to 50psi?

 

[superj]

you need to look for posts from @gaz

 

[RonD]

The 18 highway is about as good as it gets with a 4.0l Ranger
But city is too low, 15MPG would be expected

O2 sensors are the only sensors that wear out, 100k miles or 12 years, as they get older MPG slowly goes down
So change the O2s when its time, they are basically FREE in the fuel savings over the next 100k miles or 12 years

 

[RonD]

Automatics also lower MPG more in city driving because the torque converters don't lock as much as when at highway speeds, just a pill you have to swallow for the convenience of an automatic transmission

Manuals are always direct drive, engine and rear wheels are directly connected when in gear
The torque converter allows you to stop while in gear and then go when you raise engine RPMs, this slipping means more fuel is being used but not directly transferred to the rear wheels
Torque converters have a built-in Stall Speed, an RPM when they will Lock up at, and provide direct drive, usually above 2,000rpm
Modern automatics(1986 and up) also have a TCC solenoid that should lock up the torque converter at a lower RPM if speed and gas pedal are stable, this greatly improved automatic MPG
But they still NEED TO SLIP to work

 

[Angry Possum]

The 18 highway is about as good as it gets with a 4.0l Ranger
But city is too low, 15MPG would be expected

O2 sensors are the only sensors that wear out, 100k miles or 12 years, as they get older MPG slowly goes down
So change the O2s when its time, they are basically FREE in the fuel savings over the next 100k miles or 12 years

Thanks, Are they both the same the 02 sensors or do they differ from each other.? I'm Not sure what to purchase.

 

[RonD]

1993 4.0l will have two, one on each exhaust pipe close to exhaust manifold on each side

O2s come with a 4 wire lead and connector attached
They are the same kind of O2s only difference is the length of the lead, and yours will have Ford connectors, but these are pretty much universal connectors
1986 to 2011 Rangers all used the same O2s

Leads are probably the same length, I just picked up two with 18" leads and they were fine, make sure the wires can't touch exhaust pipes, they will melt
And be very careful not to reverse the sides, so do ONE SIDE at a time, so you don't plug in the left O2 to the right side truck plug, on my 1994 they are right next to each other by the firewall

 

[racsan]

I had a 93 4.0 , it was my favorite ranger, was a supercab 4wd manual transmission with 3.73’s & 235/75/15’s. Highest ever milage was 19. average commuting milage was in the 17/18 range. lowest was 12, but that was because I was towing a 6x10 box trailer, Its a light trailer but the wind resistance made it feel like you were hooked to a parachute. One day for the hell of it I tried going as fast as it could with the empty (at 1,000#) trailer in tow, normally that truck could do 90+, but with the trailer on a level backroad with no headwind 72 was all it had. once the speed maxed out the temperature guage started going up. By comparison my 2.3 ranger wont go over 60 with the same trailer. in town milage I think was 15, Hands down Id have another.