I am a new ford owner, I just bought a 1995 f150 with a 5.8L engine. The truck has 48,000 miles. This may be a long post, please excuse my ignorance concerning fords as I have allway been a GM owner in the past. Here goes. I have put about 200 miles on it and the gas mileage really sucks. What can I do about this? Would new plugs and wires, help. Also the stock wheels have been replaced, it now has 16 inch rims and tires. Is there anything that should be changed to accomodate this mod. Also any suggestions on what mods might help. I am also looking for a site where I can enter my vin# to find out rear end ratio and other information. Any suggestions, help a new ford owner be happy.

Thanks in advance

 

2001ssde,

I think a good tune up would be the place to start. You can get a ford motorsport tune up kit from Jeg's or Summit. This should include Cap, Rotor, Plugs, and the Motorsport Wires for around $100-125.

I had an 84 Bronco with a 351 as well, that I picked up for fun. It had a 4 inch lift and 33 inch tires. A real gas hog. Got about 8 miles to the gallon. I tried a new intake and cam. I replaced the piece o s*&% variable venturi carb with a holley replacemnt and that helped as well. Got it up to around 10-11 mpg. But it had the stock 3.08 gears. As soon as I swapped the fronts and rears for 4.10's I noticed a big improvement. I got almost 14.5 to 15 mpg. I know that's not great, but for that type of vehicle it was a pretty good improvement.

I would check your door jamb. There should be a stiker on it that will give you the code or it may even give the ratio, I can't remeber. But if it's a stock vehicle without the tow package or limited slip, I'd bet it has 3.08 gears. With 16's I'd switch to at least 3.55's or maybe 3.73's.

Hope this helps,

John

 

welcome to the world of fords.

You didn't mention if you have 4x4, long bed, x-cab, etc. The extra weight hurts. I have a 94 shortbed, reg-cab w/4x4 and 5.8L. It has 3.55 gears. I was getting 14.5 mpg combination town & 55 mph backroads. I just recently got 31x10.5 to replace the 30x9.5 (15 inch rims) and it seems my mileage has dropped tremendously, low 13's. Part of this is probably due to the odometer error. I bought it with the 30x9.5 and doubt that the guage has ever been calibrated so it's hard to say what the real mileage is. I have had 16.5 - 17.5 straight highway. Still not remarkable. My brother has an '02 x-cab 4x4 w/5.4L and he gets 1-3 mpg better than I do. Plus he has more power. Old technology I guess. Anyway, I love the engine and it has tons of power for what I do. I can tell a big difference between it and my 95 4x4 w/302.

I put plugs, wires, cap, rotor, fuel filter, K&N drop-in, sea-foam fuel cleaner etc. The engine runs great but the mileage is probably as good as I'll ever get.

Good luck!

 

drm7,

Good oint about the speedo. Forgot to mention that one. If the tires have been swaped for a different size it will throw off the mileage. Which could lead to a 1 or 2 mpg error.

One way to calculate how far off your speedo/odometer is would be to start from a location and go to a location you know the exact distance. Read your odometer and note the difference.
Divide acutal dist by odometer reading and it will give you a multiplier to use in calculating your mileage.

Example- known distance = 10 miles
Odometer reading = 9.5 miles
factor 1.05

Odometer Mileage= 200 miles
Fuel=15 gallons
MPG=13.33
Corrected MPG = 13.33 x 1.05 = 14

I used this on my Bronco and it was fairly accurate.

John

 

Also if the tag says Axle = H9 you have 3.55 limited slip. If it says 19 you have 3.ff no limited slip. If it says anything else you will definately have less than 3.55

John

 

check your pcv valve or vaccum hoses. this affects gas milage. plugs and wires could help and also check coil packings. add some STP fuel injector cleaner to fuel to clean carbon out of engine and after you run a tank or 2 of that stuff change your oil to a synthetic (mobil 1)