my truck will never ever get decent gas mileage.

i've done lotsa crap to my truck and just recently fixed my EGR Sensor which got my check engine light to turn off but my gas mileage is still runing 9.9 mpg city driving (with a grandma foot petal) WHAT THE HECK! its MOSTLY city driving but still i mean is 12 mpg TOO MUCH to ask for? all i'd like is 12 city 15 country and i'd be VERY excited THATS ALL I WANT!

sometimes my breaks squeel when its wet, how would i know if i have a break rubbing or not? thats the only other conceivable conclusion i can come up with.
oh and one more thing my engine likes to do some light pinging so POSSIBLY my timing is off too (who knows) anyways just venting my frustration. with prices at $1.45 a gallon and me making $5.35 (im 18 cooking at long john silvers it sucks i know) its just expensive having a vehicle that doesn't get mileage. heck might as well buy a v-10 or a 460 i'd come pretty close to the same mileage!!!

ok well if i get no more suggestions i'll just give up and maybe i'll get a thousand dollars out of this truck when i sale it.

 

my suggestion, find an AOD and a 3:55 rear, my dad has that setup in his Club Wagon and gets 16 on the road and 12 or 13 in town ,in a 5k pound van. That 3 speed is what is killing your milage. Altho my 87 got 12 win town with broken exhaust manifolds. What rear do you have?

 

With all the money you put into it you could have bought some large quantities of gasoline.

 

how do i figure out what type of rear end i got?

 

There is an ID tag on the cover. And also there is a number on the door jam sticker under "axle".

 

my axle thing on the door says "19"

 

You have 3.55 open differential.

think twice about Overdrive. It won't do you a damn bit of good if all you drive is in town. I NEVER use OD in town (even if it's around 40mph) and I get about 15-16 in normal town situations.

 

is that a good axle? 3.55? lol i have no idea

overdrive would help with highway driving, but i rarely do that anyways. oh well i'll just cut my losses lol it works what more could i ask for?

 

My 302 gets about 14 city with 3:55 gears. Can't complain at all with 101K on it. It was lower then I bought a brass tipped distributor cap and rotor from napa and platinum plugs. Other than that it's stock. It's a great 4X4. Oh ya, and I never take it out of OD when casual driving.

 

If you are getting less than 10mpg now with a light little 2x4 truck then switching the rear end and transmition will not do you ANY good at all. Around town there will be NO difference (OD is not even used) and on the highway it will be so minimal it wont matter. There really has to be something in the engine that is causing it to burn so much gas. My truck gets 10, but then again, mine is alot bigger too. If your really concerned about gas maybe an upgrade to a newer truck is in order....probably the cheapest way to go considering how much your truck is worth now.

 

A month or so back, I was talking with my mechanic about my truck pinging. I had already changed plugs, wires, cap & rotor - a basic tune-up - but the pinging continued. I had already routed the 3/4 and 7/8 plug wires away from each other too..... He suggested to "blow it out". He said to run it in L1 and bounce it off the rev limiter a few times. I did that, and (fingers crossed) it hasn't pinged since I did that! I'm going to get gas today and try backing down to 87 octane and see what happens. I've been running 89, but it would still ping with that. We'll see - I hope I didn't just jinx it!

BTW, my truck is a '90 XLT Lariat with a 5.0. I'm scared to check on a regular basis, but I think I get around 15 mpg avg.

Wade

 

Suggestion- Check your thermostat- run only a 190/195 any less and your truck will never leave startup mode, which is richer and is the "choke" on an EFI engine. Never run without a thermostat or a cooler one. It won't solve cooling problems to do this either, if its overheating its something else. On the same note check the coolant temp sensor on the intake, if it is bad it can do the same thing. And both of these problems can be invisable to the computer when you check the codes Check your cats if the converters are plugged (which is common) it won't have the power and fuel mileage it should. (mine were) Check the timing, bump it up as far as it will go without pinging. My 5.0 likes 14 degrees even with 87 octane. It felt much stronger just setting the timing up. You will have to play with it, every engine is different. Mine gets 15 mpg backroads and highways if I drive gentle, 13-14 driving like I usually do. My truck is a F250 4x4 that weighs around 5800 lbs. I'm guessing your truck is about 4500 lbs. I have 3.55 gears and 33's which isn't a good combination for milage. I wouldn't change any driveline yet, it won't help, I'm sure it is an engine problem. I know people with similar trucks that get low twenties for mileage.

 

WHAT THE HECK! its MOSTLY city driving but still i mean is 12 mpg TOO MUCH to ask for? all i'd like is 12 city 15 country and i'd be VERY excited THATS ALL I WANT!

How much does it get on the highway, I mean all highway? I noticed a huge drop between highway and city driving. With my 460, I get almost 12 on the highway and only 8 in town.

I think if you get 12-13 on the highway, it is about normal for your truck. Was '88 fuel-injected? If not, carb had lower mileage. But if you have EFI, check the computer codes. I know that replacing oxygen sensor often helps.

If everything is right, you still won't get very good mileage because of OD. You need an OD on the highway to lower your RPMs. I had a 70's sedan with a 3-speed which only got 13 on the highway, less than 10 in town. Replaced carb and the mileage went to 10/16. mpg.

Anyway, just get the tune-up checklist and go through items one by one. Alignment? Tire pressure? If you tranny is slipping, that could be another contributor to poor mileage. So could a vacuum leak. ( I think )

 

I agree, 10mpg in town isn't that bad. I get about 10 in town with my '89 4x4 F-150.

On the highway I can get around 14-15

 

One other thing to consider is an air/fuel ratio gauge. It will tell you if all the temp. sensing is working correctly and going to closed loop. It may tell you how rich you may or may not be running in warm up mode. Cheap , but useful tool. Plus the lights are cooool to watch.