I just got a 1990 1ton with a utility bed. My mpg is 13 at best. I was told it should be 18. Is this correct? Also on the manual transmission mount there is what looks like a bolt coming out of the bottom. Should this be flush? Thanks in advance.

 

Welcome.
You're going to have to help yourself out.

What engine?
Are you driving in town or on the highway? If the highway what speed/rpm's?
What type of terrain?
Is it winter where you are?

These aren't good on fuel.

 

You probably have the 3.0, I had a 3.0 with the 5 speed and only got 18 on long hauls around 60 or so miles per hour. If you are running around town and not getting above 3rd gear, you very well could be getting 13 mpg. Your driving style has a lot to do with it as well. With the information you have provided as far as how your driving, no way of really knowing.

The bolt on the bottom is possibly the drain bolt for your tranny fluid. A picture would help to answer better. It will stick out some.

 

Bolt on the bottom of the MOUNT? That should be flush, it keeps tension on the rubber pieces, if were talking about the same thing. A picture would help.

If you do have the 3.0, a good tune up and a little fine tuning with the timing will go along way. I was getting 16-18 for every day driving, best was 22 @60 mph on the interstate for a full tank of gas.

 

It is a 3.0 manual.
I drove it across country and while driving it around town the fuel mileage seams the same.
Another question. Why would the vent on the rear axle be leaking fluid after I changed the fluid and wiped the vent off?

 

It seems the same? You can't guess at this. You need to do the math properly to know. Also factor in oversized/undersized tires. 13mpg is not unheard of. It kills me to see folks advertising their 3vze powered trucks as "fuel savers" on Craigslist.

 

Did you use the vent hole to re-fill it?
If so, that might be the problem.

 

No I didn't use the vent hole.

 

I drove the truck across the country. then and around town I have been getting the same fuel mileage. I base this question about the fuel mileage on what people with campers are getting not on craigslist ads

 

How many miles on it?
Same loaded weight around town and on the cross country trip with the same stuff sticking up in the bed acting as an air brake?

The 3.turd does not have the best reputation. Done a compression check? They have head gasket issues. They tend to go around 175k.
Has yours been taken care of or has it been used and abused? 10 owners ignoring basic maintenance won't do much for mileage

 

How are you measuring your mpg's?
Also, as someone pointed out.. your tires, what size are they? 4x4?

I was getting 13 mpg for a while, had various parts that were not working properly... it's not an easy fix.

 

Tires are 195r14
230k
Same owner for the last 11 years. He just drove locally and not much. I haven't gotten into compression test yet or timing. I will try to tackle that possibly this weekend.