So basically, nothing.

[Skunksmash]

Been reading through all the gas mileage threads. All us poor gas mileage guys looking for ways to gain a few MPG. But in the end, it looks like there is not much you can do really. You can covert to an LS engine, that's what you can do. You'll gain 4 or 5 MPG doing that. But other than that, there is pretty much nothing you can do to improve your gas mileage. Sound about right?

And this is coming from one of the few who are driving a fuel injected one. My 87 TBI 350 gets 14MPG. Its old, and it gets a lot better than you guys with the 454, granted. But man. I like to drive the truck, and I can't really afford to. I get to drive my wife's squeak toy of a Toyota Yaris sedan cause it gets 34 MPG city. Sorry about the negativity but these fuel prices are getting really old. And, its not like they're ever going back to $1.50. We had a brief hope in 2008, but that was only cause the stock market crashed so gas had to crash with it.

I don't know how you guys getting 9MPG even drive at all. I've been looking through all the mileage mods that you can do, and after spending a lot of money I'd be lucky if I netted 2 MPG. Sorry rant over

[D13]

There is no magic bullet. But there are 3 things that you can do that help significantly.
1. Know your engine's power band and gear your truck to be in the torque curve at driving speed. When driving my dad's 3/4 ton i was consistantly getting 2mpg more than he was, simply by realizing its max efficiency was at 49mph not 59mph. And don't be in a hurry - you don't HAVE to drive 72mph. I like to cruise at 65 on the highway, where the truck will pull grades in cruise without donwshifting, but the motor is right in its torque curve. That was worth 1mpg versus 75 on my truck.
2. Tune up. Get every bit of energy out of that gas. Good plugs, wires, set the timing. Run a can of fuel cleaner with Techron thru the system - then fill up and change your oil (it cleans carbon and deposits off the valves and pistons - you don't want that floating aorund in your oil do you?). Interestingly enough removing most pollution controls does little or nothing for fuel economy. But replace hoses to eliminate vacuum leaks. I found this to be worth .5mpg on my 1990 which had same basic TBI.
3. Aerodynamics and weight. These trucks get best MPG with no topper and tailgate up. Every 100# of stuff is .1mpg. Lowering may help (unless you live on my potholed road or get a lot of snow), and definitely keep/get the air dam. Hard skinny tires too (less rolling resistance).

[Desert1957]

Here is a note to the OP, my 2004 Z71 Siverado will get 21 MPG and it has 300 HP.

If you are willing to do a complete swap , with all the correct parts you can have the look of the OLD style square body with the gas mileage and HP of the new.

I think most of the people that visit or belong to this forum do not daily drive their truck's. I know for me its just another hobby I like.

Desert

[Keith Seymore]

Originally Posted by D13

And don't be in a hurry - you don't HAVE to drive 72mph. I like to cruise at 65 on the highway, where the truck will pull grades in cruise without donwshifting, but the motor is right in its torque curve. That was worth 1mpg versus 75 on my truck.

This point is HUGE.

Aerodynamic drag increases with the square of the velocity. It's not linear. Simply slowing down nets way more gains than what you would (intuitively) expect.

K

[Rubble]

Like Keith & D13 said,SLOW DOWN....used to see this lots when I drove highway trucks the guys that had to be out in front.If your in that much of a hurry,get your a$$ outta bed an hour earlier!! I use my truck daily for work in the oil& gas industry.You drive from one well to another checking it,lots of stop & go stuff & only very little highway travel,mostly gravel roads.I have compared my mileage with guys running new or newer trucks & there's not much difference..and I don't have a payment.Last year or so been running the 6.2 diesel & fuel mileage is really good! Our day rate is the same wether I drive a new truck or one that's 30 years old,so that's why I stick with these old girls,besides my repair bill is way less as well....
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[bigd65]

and you really dont gain much time to make it worth it to run 75-80 down the freeway verses 65-70.

I have a (sorry folks, but the OP said Toyota) 2011 Ford F150 and it averages about 15mpg on the freeway at 75. if I slow down to 65 i get about 18mpg average... my 87 is not a daily driver so when I get to the engine, :-), im not going to worry about milage

[meatwagon83]

this is why mines getting a diesel

[tlawre87]

Most things I see people not take into account is the amount spent to achieve the 2, 3, 4, etc mpg costs "x." Its not taken into account how long, if you will ever, make that money back by getting better gas mileage.

[MalibuSSwagon]

True that. I'd like to convert to a 5 speed but my truck is not my DD, and doesn't get driven often. So the SM465 is the most cost effective option right now.

Ditch the mechanical fan and convert to electric. Cheap(paid $25 for a dual Windstar fan setup), and you gain 1 mpg. Easy to install with a few mods.

[bohmankid]

Give it another decade, only CRAZY PEOPLE will be daily-driving these trucks! (coming from someone who has daily drivin a square for the past 6 years)

ls swaps will soon be the norm.. crate 350's can only get so many miles per gallon.. you can squeeze the ls motors, but they also have a limit. Can't wait for the newer technology!

[pontgta]

Yeah, mine gets arount 18 highway, but i only drive 60-65 on the freeway.

87 305 with 700r4..... i hear a lot of people say gutless 305, but i do not haul anything. The only thing that i would haul is myself, so when if i ever get a new engine it will probalbly be the same 305.

I would have thought the 350 would be about be same, as far as MPG.

Oh i forgot, i have an 90 Trans AM GTA with 350tpi and 700r4, and i was getting about 25-27 highway doing 65....Now it just sits in the gargage So, areodynamic has alot to do with it..

[Skunksmash]

I think that old Ford vs Chevy thing is dying out. Less and less young people seem to care about that. I think part of the reason is, Ford is kind of kicking GM butt these days. Plus fanboyism is kind of hated online, where everybody spends a lot of their time these days. But back on topic:

The aerodynamics and speed factor are not really a problem that I have. I can see where some people might benefit from that info though. As I was already aware of them and had adapted my driving. On the highway, I get about 17mpg. Thing is, I've talked to plenty of guys who had these trucks back when they were new, and they will pretty much all tell you that they used to get 17 city, and up to 22 highway. That's with the TBI trucks of course. As for LS swaps, I'm gonna get that brand new 5.3 they just came out with. Well, in a few years anyway. Starts with 20mpg city (supposedly) and 335hp. A whopping gain all the way around, over my tired old 350.

[Rufton]

Wideband O2 AFR is a good mpg tool.

[dieseldawg142]

with the price of gas, my crew is down to toy haulin' duties & the odd sat. nite cruise. be useless (and expensive) to try improve mine, which would just get wiped out toy haulin anyways. i just suck it up, even if gas hits $10 a gal, i'll still drive it. i got a newer truck (1990) for daily driving

[tucsonjwt]

My last new truck was a 2010 GMC Sierra ext. cab. short bed. It got 15.5 mpg city/ 18.5 mpg highway, while being driven very carefully. All 3 squares I have had got 11 mpg best city/ 13 mpg highway (all 3/4 ton, 1 350 and 2 454) 8.5-10 mpg in city only driving with my current 454 is now typical.

I did have a 2000 Silverado that got 19 mpg city/23 mpg highway with a V6.

I am one of those who only drives the truck in the city for actual truck work most of the time, often using the dump conversion feature maybe -3,000 miles per year.

It is important to note that a 3/4 ton pickup is an entirely different animal from a 1/2 ton - just look at the frame and front end and you will see that you are carrying a lot of extra curb weight (maybe another 1,000 lbs vehicle weight?) My little 83 C20 dump conversion weighs in at about 5660 lbs. empty with me sitting in the cab (+ 220 lbs?) GVWR on my truck is 8600 lbs., so I have about 3,000 lbs. legal payload.

Even a new 3/4 ton pickup won't get very good gas mileage - most have 6.0 L gas hog engines (unless you have a diesel) - I read about 11 mpg city with those new trucks.

I thought about keeping a that 2000 V6 Silverado forever and junking the old squares, but I was afraid to get the new truck dirty or banged up, so it made no sense to keep the truck and not use it as a truck.

These old squares can limp along with moderate repairs for a long time, so you save much money by not droppng $20-$25K on a new truck (that difference in cash out of pocket more than makes up for any difference in gas mileage by a long shot.) I you need a reliable truck every day with no down time for repairs then a new truck is a good idea - especially if you can write off the expenses on your taxes. Otherwise, keep an old beater square for when you really need a truck and get an old Cavalier like I did to reduce gas consumption for other trips. I do fire up and drive the dump truck once a week to keep the varnish from forming, so that is where most of my gas goes - about $100 every two months or so.

You need to be a very high annual mileage driver to make a new vehicle purchase a logical decision.

[Keith Seymore]

I got called out in one of the other threads for saying I get 20 mpg with mine.... so I checked it the other week.

And - I get 20 mpg.

4.3L V6, MY6 manual overdrive, 3.73 rear w P235/75R15 tires.

K

[dieseldawg142]

Originally Posted by Keith Seymore

I got called out in one of the other threads for saying I get 20 mpg with mine.... so I checked it the other week.

And - I get 20 mpg.

4.3L V6, MY6 manual overdrive, 3.73 rear w P235/75R15 tires.

K

impressive! i would like to get a v6 square, but a long box, for a daily driver

[meatwagon83]

Originally Posted by Keith Seymore

I got called out in one of the other threads for saying I get 20 mpg with mine.... so I checked it the other week.

And - I get 20 mpg.

4.3L V6, MY6 manual overdrive, 3.73 rear w P235/75R15 tires.

K

I dont know why you would get called on that, 20 sounds reasonable for that set up

as far as mileage goes i bought a 6.0/4l80e swap for my truck for the mileage and when i got to talking to guys with duallys and i kept hearing 8-12 mpg city i figured, hell why am i going to spend all this money when i can get that with the 454, as far as i figure 15-16 mpg is more than possible with my setup using the 4l80e, and i could have more power cheaper with the 454!

[cedens]

IIRC the 82 4x4 with 305 got about 16 Hwy.... though times i swear i got Gallons Per Mile.

My daily driver the 06 Sierra i work out of (this week 500 miles already) i find its best to keep the tach under 2000 rpm's to save gas, also proper tire inflation. That beast gets about 18 on a good day. But driving back lease roads my mileage goes to junk.

Drafting behind semi's can help but its not recommended.

[Skunksmash]

How much MPG would a full, unrestricted exhaust system free up? I mean headers, the right size mandrel bent pipe, no cats, and very free flowing mufflers. It would be expensive, but these days it would probably only take you a year or two to recoup the cost. IF it actually frees up any MPG that is.

[D13]

Originally Posted by Keith Seymore

I got called out in one of the other threads for saying I get 20 mpg with mine.... so I checked it the other week.

And - I get 20 mpg.

4.3L V6, MY6 manual overdrive, 3.73 rear w P235/75R15 tires.

K

23MPG average (yes I record every fill) in over a year of driving on my 6.2 diesel 700R4 3.08 rear P235/75R15's. If diesel wasn't so expensive and my beater didn't get 25+mpg and i hadn't torn the rear end up I would drive it every day.

[andrewmp6]

Driving habits can make and break your mileage too.Like when you see the light down the road about to turn red let off the gas and coast your way up to.When you take off do it slowly not stomp it.I know driving like a old lady is no fun but for mileage it pays off.Up keep on the truck can help tires fully inflated good tune up clean air cleaner helps.Even fuel brands can very stick to the big names shell bp chevron not billy bobs gas.

[Rubble]

My 82 6.2/833/208 on 35s with 6" lift & 3.73s averaged 14-15 all winter.That's with lots of idling during the day too,truck is being driven all day long.I keep track of every fill & mileage. I have not checked it yet since winter,but it should be close to 20 now.I put 37" tires on couple months ago & no mileage check since then.Might have to go back to 35s. I drive like an old man,use the tranny to slow me down instead of tromping on brake pedal coming up to stop lights too.My 87 that I ran last year did close to 20 in the summer as well, K25/6.2/400/205 on 6" lift,35s with 3.42s.These 6.2s are not powerhouses for pulling,but they are great for fuel mileage,right now up here diesel is a bit cheaper than gas too.
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[slammed427]

My old 79 shorty actually got better mileage in town than on the freeway, turned out that was on account of the 3.42 rear end and a th350. My 74 with the same rear and the 465 pulls about 16 on the freeway at 65-70.

I plan on a TBI swap and a 5 speed. That should net me near 20 on the freeway. And its paid for, no truck payment can help offset the fuel mileage lost to a new truck.
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[MalibuSSwagon]

Hate to say it, but...

Do you really have a need to drive a truck every day? Does your job require you to have a truck? If not, why are you DDing a full size truck and complaining about fuel mileage? Honestly, for how cheap these trucks are, you should be able to afford a 30+ mpg Honda for a DD, and enjoy the truck on odd days or weekends.

I love my truck as much as the next guy, but they are not ideal daily drivers. I just picked up a 1999 Acura 2.3CL coupe for my gf. It's a midsize car, its got icecold AC, comfy leather seats, sunroof, and low miles. Got the car for $2500, and it gets 37MPG blasting the AC. Can't beat it, obviously I can't haul a car or firewood with it but that's why I have the truck.