F-150 / F-250 Ranges

[CrazyCobraManTim]

Well, my truck certainly doesn't get 40-50 MPG, but it can tow and do work that would make most GX owners cringe (try putting something large, wet and sticky in the back of your Honda).

That being said, my "new" truck doesn't seem to get even average mileage. I have a 1998 F250 (based on F150 body), with two tanks, one in the bed, and one underbody tank. I purchased it from Palm Springs a few weeks back, filled it up from 1/4 tank to full for about $28. I made it back to Glendora (LA County) with another 1/2 tank to spare - about 100 miles one-way at 75-90 MPH.

When I returned home, I noticed a faint CNG smell around the truck, and found a slight leak at the underbody tank valve. It was repaired by Wondries Ford, and then I started to notice the limited range of these two tanks (3,000 PSI system). Whenever I fill up, the truck rapidly falls during the first 1/4 reading (to 3/4 full) - usually in 20 miles or less. By the time it is at half tank, I would have driven about 80-100 miles in mixed driving.

I have never taken it below 1/4 tank and have obtained 170 miles for the 3/4 tank refill. All in all - that isn't expensive, but I could swear that one of the tanks wasn't working. I called Wondries Ford to see if they might have neglected to turn on one of the two tanks, but they said there is no shutoff / isolation value between the tanks. The tank in the bed is very large, so I'd have thought 250+ miles per refill was possible.

The former owner claims during his trip out from Texas, he squeezed 320 miles during one leg, but perhaps that was only during steady-state driving.

Any other F-series people experiencing similar ranges?

[rtry9a]

Re: F-150 / F-250 Ranges

I generally get around 18mpg on natgas with my 01 f150/7700 (5.4L, bifuel). Range depends on tank capacity, gearing, speed driven, load.

[cngaz]

Re: F-150 / F-250 Ranges

Have them check the tank valves, they are electronic ifs a factory Ford.
Our dedicated Ford quit on us because of a bad tank valve, it kept blowing the fuse, when getting it repaired we found that another tank had a bad valve that had never been opening. So with 2 new tank valves so all three tanks were working, it was surprising how much our distance and mileage improved.
If you are fast filling at a public station, your tank is going to drop some as the gas recovers from the friction and expansion of the fast fill.
Time fill at home will fill closer to full with less friction and expansion when you put it in the vehicle slower.

[rothstar]

Re: F-150 / F-250 Ranges

You didn't tell us how many GGEs you put in when you filled it up; that's the only way you can determine your fuel economy. I get 11-12 GGEs at 3,500 psi in my bi-fuel F-150. As mentioned above, I also get about 18 mpg on natural gas, so my range is 200 miles or a little over. With a bi-fuel truck you can afford to run the tank all the way to empty though.

I also typically notice that the top 1/4 tank goes quickly and the bottom 1/3 gives me about half my mileage.

Speeds of 70-90 mph sound excessive for this truck, and that alone could be your problem. I cruise at 65 mph just thinking about the money I'm saving.

Samuel

[Curtis]

Re: F-150 / F-250 Ranges

Keep in mind that the first 1/4 tank isn't being used any faster, the fuel is cooling after the fast fill and contracting. Try hitting another station within 1/2 - to an hour after filling and top off. Note the difference in how much you can add to the "full" tank after it cools down. Fuel temp in the tank can rise to 140 degrees due to the expansion process.

[CrazyCobraManTim]

Re: F-150 / F-250 Ranges

Update on the the fuel range. First - thanks for everyone's insight and suggestions.

I think there was either (a) some residual air from the recent work, or (b) the So Cal Gas pump I hit doesn't charge the same as other 3rd party vendors. I stopped at a Clean Air pump in Pasadena, and it took a noticeable time longer to complete the fill. Granted - I had the low fuel light on, but when it was done, I think it took nearly 18 GGE's!

After that fill, I now get between 300 and 320 miles to a fill-up, just enough for the week and I still do mixed driving (daily 210 freeway commute between Glendora and Burbank). I haven't checked the rear end gearing, but I assume they are 2.73 or 3.08 or close to that.....the thing is a dog out of the hole, but it can cruise all day long!

Now I need to pick up a nice low mileage used V10 Excursion and convert it.....guess I'll check out the conversion chat posts.

Cheers,

Tim