When did ford stop making the bifuel F-150 and what kind of gas milage do they get? Most of them seem to be 250LD's and 7700s with 5,4L engines. Would they ever see 18-20 MPG?

 

My 2001 Shop Manual details The CNG/gas engine, but I don't know how much longer they were produced. I believe all were 5.4's. Generally, bi-fuel vehicles get somewhat less mileage because the energy content is a little less and they cannot take full advantage of the higher effective octane of NG to increase efficiency. Straight CNG vehicles (like the Honda Civic GX), because they don't have to sometimes run on gasoline, can often get equal or better mileage.

The real advantage to CNG vehicles is in the cost of the fuel, which even at recent winter prices, runs just over $1 per gallon equivalent. Add the capital cost for conversion and compressor, plus the electricity to run the compressor. Also, this does not include any road tax, but I'm sure the government will figure out how to add that, should this become significant. Still, it's pretty compelling if you drive a big vehicle a lot.

 

When I was researching the 7700, the only option for power in the 2004 Heritage 7700 was the bi-fuel prep 5.4.

I figure that may have been the last year.

-Kerry