I have a 1999 f-150 supercab 4x4 sport with a 4.6. The truck has about 50,000 miles on. Recently i was in an accident and i ended up on my side in a ditch. I wont get into how but it was just that it got off the edge and stopped and slowly tipped over. I shut the engine off in a matter of seconds and ran home (1/2 mile away) and pulled it back over on its wheels and drove it home. Got it fixed and now im noticing something. Before the accident i was always getting at least 15 miles to the gallon. Now after it im getting 13 is all. Same driving habits and everything. The temperature has been a bit colder and a little more 4x4. Is their a reason for this drop in mileage? Would their be a sensor that might need to be changed due to layin on its side? Motor runs great...no oil leaks or anything. Doesnt seem to be any harm to the engine from tipping over. Do i have any concerns down the road with the engine? Any help is appreciative.

 

colder weather and more than usual 4x4 would do it. Did you get 15 MPG with the same conditions (cold and lots of 4x4?)

 

It's probably just the cold weather combined with the use of 4wd. The cold seasons make a sagnificant difference in mileage. I wouldn't start putting a lot of money into "fixing" it, until you can check your mileage this spring.

 

Many areas of the country have 'winter blend' gas that has less energy than summer gas. This results in lower fuel economy in the winter.

 

Thanks guys. I had thought the colder weather and a bit more 4x4 was the cause. Just tend to get a little nervous after something stupid like that happening. Im just not sure if i should hold on to the truck untill it has well over a 100,000 miles on it or try to get rid of it before that. Love the truck to death and when it gets nice ill wash it up and take some pictures of it and post them. I think i spiced it up quite nice. I would really like to get a new f-150...i love everything about them. Love driving my dads when i get a chance. Except when i go back to driving mine i swear something is wrong because it rides much more rough and i can hear noises lol. Still a great truck though.

 

You get "at least" 15MPG? damn... i know i could do worse than that LOL ill get maybe 16MPG at best... i mean lets face it, how often do we run on freeway road trips that take up the whole tank as to check freeway mileage like that? but i know my usual best is about 14MPG... and i have the same motor as you EPA states a 14MPG average, and they are usually overestimated ratings... im going to post a poll in the engines section and see where everyone stands as far as average MPG maybe this will shed some light on things

 

BTW, EPA states you get 16MPG city, and 21 on the freeway..... kind of a large gap lol but consumer guide recorded 12.5 MPG.... both in the 4.6L auto

 

By all means, i have duel exhaust on my truck. So ya i tend to want to get on it from the corners and i love to pass people. I live in a small town buy i travel 40 miles everyday on interstate driving 70ish to go to college. I am happy to say my "underpowered" 4.6 will get a hell of alot better gas mileage than the "nicelypowered 5.4" I cant complain with that. When i take my dads 00 5.4 out and drive it hard i can watch the gas gauge drop. Best i have gotten was 19ish babying the truck for 350 miles. Maybe its the hood scoops i have on it?? haha

 

see... thats what your doing wrong man... some how somewhere you are mis-calculating... at 350 miles to the tank, divided by a 25 gallon tank, you are only getting 14MPG, which is the same as i get.... 350 miles to the tank

 

I drive 120-130 miles 5 days a week all highway. last tank went 419 miles and could have gone further 20 gallons to fill up again to the top. like 20 miles per gallon.

 

I drive 120-130 miles 5 days a week all highway. last tank went 419 miles and could have gone further 20 gallons to fill up again to the top. like 20 miles per gallon.

 

gonna have to see it to believe it man... my girl had an 03 honda civic... and she pushed 23 MPG.... i just cant see that happening in a 6000lb truck with a V8.... you can tell me all you want... hell i could tell you i got 500 miles outta my truck... but id be full of crap... fact is, i drive my truck perfectly within reason... i dont speed, i dont mash on the throttle, and last i checked i had a 0% emissions rating... 0s all across the board, so i know the motor is in 100% condition.... and i barely get the 14 - 15MPG i do have... 20? sounds like a fairy tale for a truck... like i said, my camaro didnt get that, and its half the weight of these trucks... unless you somehow idled you way through 450 miles, i cant see it happening...

 

and 20 gallons? the tanks are 25 gal.. you guys got some twacked information your slapping together in the equation.... people are saying they go 350 miles and get 19MPG, when mathematically its impossible.... 350mi./25 Gal. = 14MPG. And now you think you have a 20 gallon tank...... wow dude... i can honestly say ive heard it all..... 20MPG in a V8 6000lb truck.... phew... heard some big ones in my day, but this tops em all lol its scientifically impossible... people just DONT drive that cautious... and even cruising at 55 MPH i just dont see an older 4.6L pulling that kind of gas mileage... a motor needs to survive off some sort of fuel to even run... and thus you HAVE to have a certain amount of fuel consumption... and since my motor is in 100% perfect working condition, and as i said, has a 0% emissions rating across the board, i just dont see where any excess gas i would be "wasting" is going... ive got a brand new set of plugs and wires, new IAC valve, new fuel filter, ran several tanks full of fuel injector/fuel system cleaner... always use premium gas, never punch the throttle more than is needed to moderately gain speed to cruising conditions... even if i was to stomp on it all the time, and drive like a maniac, i can only see a possible 3MPG loss... and like i said, EPA states 14, and observed by consumer reports when it first came out was 12.5 ..... so how the hell is ANYONE without having some kind of fuel efficiency modifyer program or gadget installed going to pull off a whopping 6 MPG more than me under the same conditions....... not feasible...

 

scuse me, not feasible on the STREET... maybe if you drove consistantly on the freeway at the suggested 55 MPH (which i dont see happening.... not for 400+ miles... that would take HOURS!) then yeah... you can probably hit 20MPG... best case scenario.. but im talking everyday driving here.... be real... come on now... here is what consumer reports have to say about the 97 - 03 F150...

 

Yes it is feasible to get 19. I have done it once on a long trip driving barely 55. And remember u have to use a little common sence...Just because i had 350 miles on a tank doesnt mean i put 25 gallons in..cuz if i did i woulda been walking to the gas station. YOu have to keep tract of how much gas you actually put in the truck to know how much you have used. I put in around 19ish gallons or 20 that time. The driving conditions were perfect. Will i ever get that again...doubt it...i may pull off a 17.5 again but i can usually always count on that 15.