Hello, new to the forum. I drive a 98 ranger xlt 4.0 4x4. I’ve been having terrible mpg for a while. I’m wondering where I should look to try and fix it, I’m getting around 8-10mpg between highway and city driving. There’s no check engine lights on. I do have a light on for my ABS and the 4 wheel drive doesn’t work. Could either of those systems not working effect my mpg? Or do I have to look elsewhere?
Thank you

 

When was the last time the spark plugs a wire where changed? Start there.

 

I'm not on the Welcoming Committee, but ,WELCOME TO THE FORUM.

How many miles are on your 28 year old truck?
Other descriptions of condition and maintenance really help.

O2 sensors have a 10 year/100,000 miles lifespan. It's likely past time to replace them.
Also, see to the cleanliness of your MAF sensor.

Also, the results of a compression check -both dry and wet- would do much to confirm your engine's health.

 

I changed the spark plugs and wires last year, about 15k miles ago

 

The truck has around 140k miles. The couple I bought it from rarely drove it. I’ve replaced all the O2 sensors but don’t think I’ve done anything to the MAF sensor. I’ll attach my notes page with all the work I’ve done on it.

 

121,500 oil and filter

@125,900 you say new oil, how about the oil filter ?

Next oil change @ 136,700, is that 11,000 miles on an oil change and 15,000 miles on the oil filter ?

I'd be doing a compression test on that engine before spending any more money on it.


And the new tires recently, are they the same size that were on it?

 

I do new oil and filter roughly every 5k miles. I think I forgot to record the one around 130k

 

Check your coolant temperature sensor.
When these go bad and read coolant as COLD all the time, your engine's poor brain makes it run real rich all the time.
Miles per gallon goes way down. It also shortens the life of your cats.

 

A bed cover will help a little.