Windstar 3.8L 1999: 13.8 mpg!

[smata67]

I bought this van in 2006 with 90,000 miles on it. I now have about 120,000. When I got it, I was unhappy with the 15mpg I was getting, but I was warned about it from the previous owner and really like having a van to haul my "stuff." Fast forward to 2014 and it looks like my mileage is even worse! I am consistently getting between 13 and 14mpg. I have changed the plugs, wires, lower intake gasket, cleaned the MAF and throttle body and no change. I just got an emissions inspection and passed, so I don't think gas is going unburned. Oil looks pretty clean with a couple of thousand miles on it. I did the lower intake gasket last year and my oil level is now steady and no coolant is disappearing either. Why is my mileage so dismal?

[bdahl385]

This is a big heavy vehicle, the gas mileage will be really low if doing in-city short trips. I have had my 2000 SE with 3.8L since new. When my wife drove it on short errands and running kids to and from school, 12 to 15 was the norm. During long trips fully loaded for vacations and such and on interstate roads, 21 to 22 mpg was achieved. I now use the van for a commuter vehicle driving ~ 33 miles each way in a combination of back road, residential and rural settings with posted speeds being 35 to 45 mph. I achieve 16-17 mpg in the winter and 18 to 18.5 in the summer.

[Mustang_Driver]

Yeah i was thinking the same thing.... i think they are like 5000lbs and with a v6 that's pretty hard an a 6 cyl. Now if it was a 5.0 in the van it would probably get better milage.

I was thinking about fining a thunderbird SuperCharger for mine but not sure if it would work properly i think i get MAYBE 15MPG in the city short trips now it's parked in the driveway collecting dust gas prices in Canada are equivalent 6.30per gallon (1.579 per liter) so yeah it isn't worth driving it here

[12Ounce]

I try to take a warm engine compression test every couple of years just to watch engine wear ... especially the valve system. After that I used a induction timing light to make sure all plugs are firing evenly. I don't expect cables to last over a couple of years. When I change plugs, I try to remove all injectors and do a good bench cleaning ... leaving the nozzle bowl clean and mirror-like. A drop of cleaner down each injector barrel helps to keep innards in order.
.
Brakes in order, and tires well inflated ... about all you can do. 0W-30 synthetic oil.

[tomj76]

Another possible cause of low gas mileage that I've experienced is the transmission. Before my original transmission failed, the fuel efficiency stedily fell from ~20 mpg down to ~15 mpg. At 200,000 mi the transmission failed and was replaced by a used/rebuilt transmission. There was a significant improvement after the transmission was replaced.