I Have a 92 with a 302 I only get 7 mpg I see everyone else getting 17 to 18 mpg. My truck is not lifted I'm running 32/11.50 anyone got Any ideas why my mpg is so low? Help?!?

 

Where are you at for a tune up? Nothing will be gained without a full tune up. Plugs, wires, cap, rotor. Doing the timing bump will also help. New filters, I prefer cloth filters as opposed to paper, especially in high humidity and wet areas. Paper soaks up moisture, swells, dries and gets hard and becomes restrictive in short order. Also, have you had your speedometer calibrated with the 32's? Theres no way to get accurate mpg without it being calibrated. You can get a couple more mpg with a swap from mechanical to electric fans. Also, if you show no signs of oil leaks, you can consider a swap to full synthetic fluids in the motor, trans and diff. This will actually net 1 -2 mpg. Allot of us have swapped over to warm air intake setups to decrease intake restrictions and get better intake flow. You also have to consider your differential gearing. Ford's number one highway gear was the 2:73. I got decent mpg's with the 3:55 in my '94 5.0 and it pulled great. Here are some links that will definitely help your situation. Allot of reading, but in your situation, you can't be lazy and not read all of the available info.

edit....you can accurately measure mag using a gps. Just wanted to make sure that I clarified myself.

https://www.f150forum.com/f10/just-g...ht=gained+8mpg

https://www.f150forum.com/f10/electr...tric+fans+swap

https://www.f150forum.com/f10/electr...tric+fans+swap

 

The lift doesn't effect it as much as the tire, think of it as running in a marathon in socks compared to steel toe boots. The heavier tire will require a lot more energy to get going. Another factor will be your driving, I can vary my mpg a lot by how I drive, if your racing to every red light and speeding it won't help. And lastly will be your conditions, are you driving in the city a lot or out in the country/highway.

 

What's the lift have to do with it?

 

He mentioned it's not lifted but has bigger tires. I just put my two cents in, I found when I went from stock to 33x12.5 there was a huge drop, when I put a 6" lift in with same tires it didn't effect it much. Yes it isn't as aerodynamic but our trucks are boxes on wheels, they aren't very aerodynamic to begin with.

Tires alone won't cause that low of mpg but it definitely won't help matters. I agree with the above suggestions, I have efans, a tune up with a timing bump, new filter in stock box (K&N) and saw great gains, biggest gain was the 5 speed swap but was the biggest job.

 

Did you calibrate the speedo/odometer or use a gps to measure the mpg? Most folks never realize the error in speed/mileage with tire size changes. Most folks also assume the tire size specs on the tire is correct as well. Most are not true. I'm getting ready to do the Bully Dog on my son's truck and there were a few things that their videos teach/remind you about with tuning. True tire size, true weight as the truck is used, etc. Not talking tuners here, but if having a speedo calibrated, it's worth mentioning.

 

No it's not but at 100km I'm going about 10-15km faster. By the time I've used both tanks I've gone roughly 75-100km farther, about 1mpg better then I have recorded. I know this isn't exact science but I understand where your coming from and am in no way disagreeing with you, I'm not saying tires alone will cause 7mpg but they won't help if he's serious about getting better mpg.
Big tires aren't light, they take more energy to turn them, factor in stop and go traffic in town and driving it hard and you've got a recipe for poor mpg.
Another thing we didn't mention was to check for codes

 

Ok well the truck has had a full blown tune up plugs, wires, cap, rotor, k&n air filter, and I run synthetic oil. I know I stated that I'm running 32/11.50, I understand that running a larger tire decreases fuel mileage. But even when I ran factory tire size I only got about 9 mpg "I meant to add that to my original post my apologies." As far as codes go how would I check that it doesn't have obd2 scanner connection? Thanks

 

Also what's a timing bump?

 

Okay there's a how to stickied on how to do it with a paper clip, there's no obd2 port as you have an obd1 and hopefully someone can post a link on the timing bump, you advance base timing allowing for a more complete burn, but is check codes first