I have looked at all seven of the pages on gas mileage and I think I am getting about the worst. I can't seem to get over about 330 miles (if I'm lucky) out of a 30gallon tank. I have a 04' fx4 supercrew with the triton 5.4 and 3.73 gears. The only modifications are super 40 flowmaster muffler dualed out and toyo a/t 305-55-R20. I don't think that the tires should take the mileage down that far. I only use premium 91 octane and stay out of the throttle. I would say I drive 75% of the time on the interstate at 80mph. My truck never sits and idles because I am afraid it might drop into the teens. Does anybody think I have a problem, should I take it to the dealer? It should be past the break in point it has right at 4,000 miles now.

 

I think you are wasting your money on the 91 octane. The truck will run just fine on 87. The other problem may be that at 80 mph you are greatly increasing the wind resistance and drag from your truck which will reduce your mpg. Do you have a cover for your bed?

 

Your mileage is about par buddy.

I use 87 Octane, average 15.2 MPG right now, and the faster I drive, the lower the MPG.

Big Truck, Bad Mileage. BUT...It looks great and rides like a dream. Start liking it.

 

I don't have a bed cover. But you guys are probably right the truck sits high (2.5" leveling kit) and I am sure the 33" tires and driving 80 helps the mileage much.

 

I can go about 320 miles before my low fuel light comes on with a 27 gallon tank. Given your mods, I don't think you're getting anything unusual fuel mileage wise.

 

if you don't have performance PCM tuning, nix the high test gas. It will probably give you worse mileage than 87 will stock.

 

What he said. You are wasting your cash bro.

 

I also tried using higher octane for a few tank fulls, and could discern no difference.

 

Dan:

I have tried various things such as a cover, exhaust and high octane fuel as an experiment. None of these improved my gas milage whatsoever.

MYTHS:
A cover will increase your mileage. Not true. I actually got better gas mileage without the cover. Not much (approx. 0.3 MPG better), but it was still more.

Higher Octane inproves gas mileage. Also, not true. (Ford recommends 87 octane. So I would trust the builders before anyone else. Mine runs great on 87. Just try different gas stations to see which make your truck happy ).

If you want to drive 80 MPG and expect good gas milage, then you should look at one of those half gas, half electric buckets. One of those will get er' done. :thimbsup:

Remember, you own a HUGE Truck. Like it & Love it.



Good Luck, Carl

 

Dan,

I have had my beautiful truck since Oct 28th, 2003. I have always had poor mileage since day 1. I, too, have a bed cover and I have the Borla exhaust.

I, in the winter time, average about 280 miles to the tank on the highway. I am hitting 9-10 mpg. Summertime I am getting about 13 on the highway tops.

Yes, it sucks, however I love this truck and will own it until it dies! I have stopped checking my fuel economy because I know it is going to SUCK no matter what I do to it. I drive 70 mph with the cruise on and there is nothing I can do about the mileage.

Just enjoy your 35k truck!

 

I did notice a slight increase once I switched to synthetic oil. You could try that and see if it works for you.

 

Dude, WTF? I have essentially the same truck as you (stock FX4, no bed cover or supercrew though) and I drive 75 on the interstate, and I have been geting over 16 mpg, even during the break in period. I have 1900 miles on it so far, and last tank was 505 miles (I have the big tank)

 

Well, I switched to synthetic about 2500 miles ago.

I just turned 13k on my truck. I have taken it in a few times about a year ago to have them look at it and they told me that there was nothing wrong with it. According to thier 10k machine, they said that my truck was getting 16-21 mpg city/highway. I don't have a clue what drugs they were on or what battery was powering that 10k device but I have NEVER gotten over 13.8 mpg with this rig. I have even gone on a trip with the cruise set at 55 mph all the way; drove 104 miles total and filled up at the same pump as what I filled up b4 I left and then I got 13.72 mpg.

I pretty much gave up!

I love my truck, though!

 

Matt,

I have seen stats on elevation to gas milage comparisons. I know Minnesota sits around 1200 above sea level and NC is about 700.

Less oxygen intake = more gas burned

I'll try to find the link where I read it and try and post it later. Maybe this answers alot of these poor gas mileage questions.

 

i get anywhere from 10 mpg from doing 90-100, donuts in the rain and off roading to 19 on the highway going non stop to dallas. if your somewhere imbetween there your good