Mpg problems
Record Breaker
Joined: Apr 2010
Posts: 1,745
Likes: 50
Funny thing...my 93 3.9 2wd, gets only about 14-15 highway. 10 or less city. I have fixed all my vaccum lines, new fuel pump, pres. regulator, filter, plugs wires cap n rotor, and o2 sensor. normal sized tires and no I'm not hualing anything constantly to get that poor mileage. I think there is a reason this motor has the nickname of "Boat Anchor 6" I find it amusing that a mild 5.9 will get better mileage long as I keep my foot out of it.
I have also had a couple 3.9s. My 1st was a Pre Magnum and would get a consistent 20 on the highway and 16ish in town; this on a 90 Dak longbed that I had several years ago.
My current 94 RC shortbed will "almost" get me 18 with a worst of 12; this, when towing my utility trailer w/my mowers on it. Typically when we have winter gas in the stations the 94 will get me about 15 with a mix of 70% highway 30% in town. with summer gas that improves to the "almost" 18 I mentioned above. I was hoping for 21-22 from the '94 which I still currently own. This truck is sitting since i got the 93 318 powered clubcab since I had to steal the license plates from the 94 to put onto it
But I plan on swapping them back and driving the 94 for the winter since being a reg cab I "care less" about this one than my CC truck which I want to keep in the great condition it's in. (so I don't want it driven in any more winter salt than it may have been by the PO)
I have known people to have both engines in different vehicles though, that have gotten better MPG than that out of... as well as worse than I do.
Most vehicles I have owned over the years, I have had at least 2 of; and even so, same make and model, same engine, same gearing etc it seems that you would reasonably expect them to drive the same, get same MPG etc
Veteran
Joined: Dec 2011
Posts: 433
Likes: 0
From: Knoxville, TN
Some other factors we all really miss I think is humidity levels and whatnot, it really effects how well an engine runs honestly. that and it also comes down to what other work we do to the engine, I'm having the heads worked and opening up the motor for it to breathe better. That will directly affect the mileage with cruising at normal speeds.
