I just bought a 87 4.9L 300. It has a 4 speed with granny low. I'm getting about 14mpg regardless of how I drive it.

Is this about normal?

Any suggestions on improving it?

 

some information would be helpful:
2WD or 4WD?
What rear axle ratio?
What size tires at what inflation pressure?

14 is a bit low. Start with a tuneup.
What do your plugs look like? Black? Grey? Tan?
While you've got them out, do a compression test.

 

2WD. Not sure on the rear axle ratio, only had it 1.5 weeks and it seems to be monsoon season here in Alabama, but it is stock.

Tires: Federal 31X10.50R15LT MS 351 A/T. Running 35psi.

Plan to pull the plugs the next time I'm off work and it isn't raining....Maybe June....

 

look on the door jam sticker it should have a code for the axle. whats the average speed you drive? most of my dads customers see about an average of 15mpg for the 4 spd, thats going anywhere between 15 and 60mph.

 

Welcome to the site! That is about what I got out of one back in 1988. They are not known for the fuel efficiency.

 

Was kinda expecting that to be the norm. Doesn't matter how fast or hard I drive it, it is always between 13.88 and 14.65mpg. Highway or town. Figure it probably needs a good going over and maybe it will get a little better. Anyway, 1.5 weeks and still lovin' it.

Now I just got to get my 97 running again and I'll be in truck heaven.