I bought a 1996 F150 with a 351 in it, 4x4 of course, and I decided to check my miles per gallon. I was shocked to see the number 11.5 come up on my calculation. Is that a normal number?? I was atleast hoping to get 14 or 15 out of it.... My 71 390 got 8, and it is one of the worst gas guzzling engines ever made. So, is 11.5 normal, and if not, what could be the reason for such poor performance?

 

thats pretty good for a 4x4. mine gets 12-14mpg, but yours has efi so you may want to take a look at it. when was the last time the o2 sensor was replaced? how about scanning for codes?

 

I get 110 miles to a 20 gallon tank in my 1990 bronco 2, I think that is 5.5 mpg I have a 2.9 v6 aut 4x4.


those guys who get 30plus are probably going 50 mph on the highway.

my friend gets 10 mpg in his mustang 4 cylinder driving normal,

my dad gets 14 mpg on the highway in his diesel f350

in a truck 11 is decent mileage i think.

 

Gallons- Miles- MPG
12.52- 134,875- 14.16
15.54- 135,046- 10.99
15.25- 135,250- 13.36
17.61- 135,450- 11.38
15.51- 135,665- 13.88-300lbs of sand removed
14.90- 135,859- 13.00

my mpgs range because of stupid people and my right foot suddenly getting heavy along with a cold winter

 

somthing for sure isnt right. pull codes, do a tune up with new copper autolite plugs, new ford 9mm wires, cap/rotor . change fuel filter and maybe even your o2 sensors . then look into an msd coil while your at it this will give you better combustion at all rpms. I have an 88 bronco with a 5.8/auto and get 12city 16hwy.
also what size tires are you running??

 

My tires are oversized. They are 32x11.5. Its not a huge difference, but I guess enough to compensate for a couple of MPG. Also, I think you are right about giving it a full tune-up. I was looking at the plugs and I think they could def. use replacing. I will check out the O2 sensor afterwards if the mileage doesnt increase. I hadnt thought of that. Thanks for all the help, I will let everyone know the results as soon as I find out.
THanks again!

 

You need to check whats wrong with the bronco and mustang. I have 2 90 rangers with 2.9 engine - 1 auto 1 manual. Both get 21 -22 mpg and thats riding 70 - 75 with loaded tool boxes on the back. Same with mustang. My 97 GT gets 24-25 mpg and isn't driven easy.

Kemicalburns is right. Something is wrong if you get 11 mpg with an efi engine.

 

I get 65 miles to half a tank 10 gallons, I have a 20 gallon tank. that comes out to 6.5 mpg on my calculater, but I do not see how a 177 cid could do that with so little toruqe. It has 180,000 miles on it 1990 B2. The bronco2 makes decent power after 3700 rpm, if you want to pass you are looking at 4000-5500 rpm, that is where my gas is going.

the mustang has only 86,000 miles and it is a 1986. On the mustant it is torquey up to 2000 rpm and at 2000 rpm acceleration stops and you can rev it up to 5000 rpm and you do not get any more speed unless you have down hill or you can draft on the free way up to 65 mph at 3500 rpm.

But any way even if I can't fix these vechiles at least it might make this guy feal better about his truck. I would be happy if I could get over 10.

 

I have a 302 EFI that was getting 6-8 mpg. Turned out to be the fuel pressure regulator giving me 65PSI!. I get 12mpg now, but I want more.

-O2 is new
-Plugs, wires new.
-Ran some injector cleaner.

I got a question on the Cap/Rotor. Does it matter what Brand I use. At Advance auto, the GP Sorensen is the 'OE Style'. Would that be good for my cap/rotor? I've used their sensors and work well.

Also, my EGR valve is shot. It never opens, so I'm losing maybe 1-2mpg there??

 

I pulled coeds once and I had 2 codes,

41 ego (ho25) my engine does not change air fuel ratios,

66 air flow (maf/vaf) signal low -ckt gnd

My vacume lines have been hacked up so I had to plug each vacume port up except for power breaks which is still hooked up.

I do not need to smog check until next july and my scout should be built by then so if my B2 is not right it will not be so bad.

 

those cap/rotors are fine. i use them as well. and have not tried any others. its kinda like my plugs. its just better to go cheap on something that needs replaced often enough.