11 mpg to 15 mpg is it possible mostly on driving style and small mods?
 

My rapidly growing family forced me to get a new vehicle and since I can/do use a pick up truck my hunt was on for a crewcab truck that I could afford. Jump ahead 3 months and I got a great deal on my new truck. A 1997 F-350 crew cab long box 4x4 5.8L with the automatic with overdrive. I didn't really want the long box or the 1 ton but the price was right and older crewcabs that aren't rat beat are not common around here.

Here's what it looked like when I first got it.
http://lh4.ggpht.com/_w1_9lMbNbxo/Ss...0/IMG_3337.JPG

Anyways I filled both tanks up before driving home the first time (19 gallons/72 liters front, 18.2 gallons/69 liters rear)
Since getting it home I removed that spare from the front and put it in the bed. I also threw the original under inflated bald mud tires away and got 4 new good year wrangler Silent armor tires. They are a semi aggressive All terrain which should be good in the snow and occasional offroad that the truck will see. I know they are not a good choice for mileage but at least they aren't swampers.

Anyways
I decided to drain the front tank before switching to the rear and had gone 220 miles/355 km when I switched tanks which gives me about 11 mpg.

I'm aware that the truck is a beast but I'm not hoping for miracles so I'd like to get to 13 mpg. 15 would be awesome.

I figure that driving style can get me part of the way so I've ordered a scangauge that should be here next week. My old truck had a 1.6 L engine and as a stick so driving it efficiently could be very different then the new truck.

I'm slowly doing the basic maintenance to make sure the engine is running well

I'm going to put a canopy on the truck and I'm aware that it will probably make the mileage worse. I was reading bondo's thread about his aero cap but he's not going to be making one for my truck anytime soon and based on the prices I saw in the thread it would cost almost what I paid for the truck so it's out of the question.

So I'm wondering what everyone recommends? I see someone on here has slammed and re geared a F-350 to get close to 30 mpg but I think he has a diesel?

...get something like a ScanGauge II to "tell" you what MPG is happening in realtime, and YES, you should be able to go from 11 to 15 mpg...but not at a lead-foot speed!

I always though it would be neat to make a jon boat that doubled as a cap, with the bow to the rear.

regards
Mech

Yeah, you can get 15 out of that, but it's going to take time, patience, and re-learning how to drive, if you plan to keep doing it w/ that automatic.

If you're got a u-pullit yard near you, you can probably get a 5 speed OD swap for less than $200, buy a new clutch for $100 or so, and you're good to go. It'd probably be the first thing I'd do. Beyond that, see if you can find yourself a 6.9 or a 7.3, preferably Turbo. They can both be installed as standalone engines, with no real work necessary to the truck, other than installing and changing fuel systems.

I usually see these engines on craigslist for ~$500 or less, often in good running condition, and parts for them are cheap.

Another great option would be a 6BT Cummins. You can see where this is going.

Oh it hurts me to see people buy vehicles like that. (Getting a "good" deal on them) I really think with a truck or a large vehicle that you are better of adjusting the "nut", and doing a few aeromods. I don't think you want to swap engines (if you don't want to get a cap) but if you do Christ is right.

lists:
bed cover
passenger mirror delete
driver mirror smaller
grille block

I could drive a Hummer around all day

then come home and pour a gallon of gas on the ground and light it (or not)

crank up the furnace with all the windows open

and still have less of a carbon footprint

due to keeping it sleeved.

Well this is my daily driver but since I'm a stay at home dad my daily driving doesn't add up to 400 miles a month. We use my wife's car for pretty much everything when she's home and it gets far far better mileage. It however isn't going to pull a travel trailer or haul a cord of firewood or a bed full of manure home.

So yes it's an environment destroying truck. At least I use it to do things that require a truck.

Scangauge ii should arrive next wednesday if the post office tracking is to be believed. I started reading the manual. My only real concern is getting it calibrated. I'll have to do a bunch of small fill ups for awhile so that it doesn't take me 6 months to get it dialed in. I'm currently filling up every month and a half or so.


an engine swap is unlikely any time soon. Diesel engines up here cost a lot even when very used. There was a 7.4 with 350,000 km on it listed for $2000 about a month ago. It was pulled from the truck so you couldn't even hear it running. Also diesel is just a bit cheaper then gas, roughly 4% right now. So I seriously doubt I'd ever recoup the cost with the swap. The 5spd with overdrive swap could be more promising dollar wise. I'm not too sure how difficult the actual swap would be though although I've pulled an engine and successfully put it back before so it's probably within my skill range.

Well I think 15 is possible, but it'll take some serious work. Back in the very early days of my questing for gas mileage, I had a '92 Bronco (same bodystyle generation) with a stock 302 and automatic and averaged around 13,3 in mixed driving, 18+ on the highway. Yours has the advantage, I believe, of sequential fuel injection vs. batch fire on my older 302, and I think they had roller cams in the 351's by then which my 302 also didn't have. Plus you have have a mass air system versus my speed-density EFI, so you have three advantages right there if I'm right on the roller cams.

I am a little jealous, that was one of my favourite truck bodystyles with a crew cab and a 351...it's a nice combo. I had a chance to buy a similar truck with a 460 but I'm glad I passed on it. Also had the chance to buy a '95 Eddie Bauer F150 with a 300 straight six and 5-speed, I regret passing on it. 5-speed would be nice though the 5-speed Ford trucks that got EPA mileage ratings got lower mileage, so I don't know if the final drive gearing is less advantageous on the manuals.

I have so little experience driving trucks like this, I can't honestly say if that's a realistic goal.

But the ScanGauge purchase was definitely the right first step. With the amount of fuel this thing will burn in a year, it'll more than pay for itself!

Weight reduction tip: don't fill both tanks if you don't have to.

Not sure what kind of driving you do. but I was getting around 12 in town with my 89 F150 2wd 4.9 5 spd. I'm up to 25 average in town and just got 30+ on a long trip mostly rural road mixed with some highway.

I have an advantage in that I have a diesel, a manual trans (but no overdrive), and a standard cab.
My starting mileage is the same as your goal.

But with relatively minor changes I brought my 1983 F-250 from 15mpg up to 25mpg average with mixed loads up to 3 tons (28+ running empty)

Vehicle efficiency upgrades: 28.5mpg (so far) in 2.5ton commercial truck

Its easier to have big increases when you are starting from such a low number. In a small car +10mpg may only be a 30% improvement, while for you that same 10mpg would be 90% better. 4mpg is totally possible. Ford wasn't trying to make these things fuel efficient in the least, so there is all sort of room for improvement.

Coastrider - That's amazing. I see that you regeared from the 4.10 which I also have. How much did this account for ? what are you doing driving wise that you think is most benefitial? Also I see you have a kill switch and starter button I'm assuming for engine off coasting? Is that even possible with an auto?

15? Sure. ESPECIALLY with a Scangauge. Keep it around 50 mph max and do lots of neutral coasting. The Scangauge will "guide" you from there.

I wish I could use a Scangauge for my Broncos. I'm still eyeing that MPGuino thingy.

The gear change helps the most at higher speeds and continueous driving with the 4.10s at 65 mph the engine ran at 2500 rpms now its at 2000. keep in mind I got the gears free from a friend and installed them myself, a gear ratio change runs about 600 each axle new gears install kit and labor. with a 4x4 crew cab 5.8 and an auto I would go any higher ratio than 3.55's

Engine Off Coasting and not idleing have given me the biggest increases,
the bricklike aerodynamics of these trucks doesn't allow for much P&Ging esp at speed the glide is shorter than the pulse:(

Most of my driving goes like this: I start out in 2nd gear get to 25 mph (the usaul speed limit) hit the kill sw and coast to the next light or stop sign useing momentum and the grade to maintain speed. There are very few flat sections of roads where i live seems like I am always going up or down.

I feel the only purpose of the engine is to move the vehicle forward so If it isnt doing that its off

automatic transmissions should be fine for short distance EOC major down side is not being able to bump start.

TCC lockup switch is an option too. (And cheap) I am just testing it now but it seems promising. I'm also doing a lot of coasting with an auto. Not a problem on shorter than a kilometer coasting. Ditto on the no idling/coasting gains.

Also you could easily do an alternator disable switch and a deep cycle battery unless you are driving up to Nanaimo and back one should easily do for around Victoria.

Scavenge an electric cooling fan and remove the engine driven one if so equipped.

If most of your trips are short, a block heater. This one is a wife favourite: instant heat.

Oh, and synthetic oil all round: Trans, engine, diff. It's cold up here.

light bed cap
 

I got a softopper for my Tacoma, there was no difference in overall mileage. They only weigh about 40 pounds yet covers & keeps dry.

I'm starting to wonder if I've got a slightly sticking brake. Some days on a flat surface you can put the truck in drive and it will slowly start moving. Other days same situation and you need to use the gas a bit to get it to start rolling. I can't see any other reason that it wouldn't start rolling.

scan gauge arrived today. I'll install it and fill the tanks up. I'll be running both full for a bit while testing to make sure the transfer mechanism that allows dual tanks is working. If it fails it's not uncommon for mileage to suck because it usually fails in a way that has it returning fuel from the engine to the wrong tank where it bubbles out the filler and onto the road or it floods the charcoal canister with the excess. I know it works fine if on the rear tank. Just need to test on the front with the rear empty.

Do they salt the roads there?

They do here. :mad: After a few years the caliper slides get corroded and they stop sliding. Then the pads don't retract away from the disc. Then you waste gas and brake parts.

Now I grease parts that originally were assembled dry. Of course, none on friction surfaces. Time will tell how much longer they'll go.

When I get the chance I'll have to pull the brakes apart and grease everything up again. It's not a bad idea to check the pads to see how much life they have left in them anyways. They salt sometimes around here but snow/ice is rare. Although last year we got tons.

Bad news on the scan gauge II. my truck is a 97. It's grvw is something like 9200 lbs. That means it was exempt from the ODB2 requirement and doesn't have the plug. So when the scan gauge supported vehicles says all Ford vehicles for 97 what it really means is all vehicles under 8800 lbs which is everything but the HD f-250 and the F-350.
Stupid thing is if this as a california vehicle it would have had to be OSB2 so Ford made the F-150, F-250, california F-250HD, cali F-350 all odb2 and the rest of the country F-250 HD and F-350 odb1. how the hell does that make any sense.

I doubt I can return the unit since it was mail ordered from across the country so I suppose it's onto ebay.

Thats a bummer about the ODBII not being there. the ScnaGauge would have been a big help for you.

First

Get vacuum gauge. and turn off overdrive until you go over 50 mph if you have 3.55 gear.


I have 96 E350 passenger van it weight 9,000 pounds. 5.8L with E40D.

gear ratio was 3.55

Most time I get 13 mpg in city and 17 mpg on highway load with 15 people.


When I didn't have vacuum gauge I got 9 mpg in city and 12 mpg on highway.

Keep vacuum gauge pressure about 10 or high is best.

Make sure 4wd hub lock out are disengage correct. Most time they get old and stuck which cause 4wd work all times until you notice mpg terrible.


You wouldn't see 12 mpg or high due you fill gas tank per month which gas can disappear. Example you have 5 gallons of gas but 1 month it 3-4 gallons due leak fuel cap or leaky tank.

Why turn off OD?

I lift at 42mph to kick it in sooner.

Not for 5.8L with 3.55. But for diesel Yes.

When it kick overdrive in 40 mph and vacuum gauge drop FAST. like it should be 10 or high to get great mpg when overdrive kick too early it went to 0-2 which is bad plus it lug engine.



I put 10,000 miles on van so I know how it work. I try with overdrive under 45 mpg and didn't get 13 mpg it was 9-10 mpg plus it get little Hotter than normal.

My dodge is like that also, there are many circumstances when I get better in 3rd than 4th because there is so much slop going on sub 48mph especially if I have to press on the pedal at all, usually I can't maintain speed without massive FE hits in 4th if there is wind, hills or a reason to accelerate. If I end up in 4th around 40-50mph I keep my fe high or even coast loose speed and speed up again as opposed to trying to accelerate in 4th, manual downshifts seem to result in a bump in my fuel usage for some reason (even with my foot off the pedal)

Strange how automagics are setup, I really can't understand what the purpose of many of the behaviors I encounter on the scanguage are, especially the coasting downhill with foot on pedal to maintain speed then FE drops from what it was on flat ground while going DOWNHILL!

Bleh, I really am starting to dislike automatics

I am glad to read this, I knew of the diesel secret since I was a kid.(25 years or more) today, add turbo, and calm it down. wow. I always assumed, as america hurts itself for the capitalist, the diesel trucks into the high twenties raised prices...strangely so, as diesel is easy to get from petroleum.

My truck experience and the same 15 mpg left me scratching my head. I would swear that is a minimum. OE keeps the lean out for heavy hauling. If you are not hauling, get dynamical with the injection, if it means a piggy back computer. Step up ignition if it needs it, and even the oil pump.I have stepped up the carbs into 20s quite easily (3/4 ton 5.7 chevy)...but it pinged in loads. that is when I deciphered the "einstein" of trucks left as oem...they make it run pig rich to last the 5 year pay plan... ;)

I still want a diesel, 1980s suburban style with something modern under the hood.

Is this a repost or am I caught up in a bigger repost? :eek:

Only, why would anyone get a big truck if they aren't hauling with it?
My 25mpg is with hauling, and hauling lots of large heavy loads (full apartment worth of furniture and boxes, 3 tons of broken concrete, etc) and it sounds like the thread OP is planning to use the truck as a truck too.
Also, I don't have any computer to play with. Wouldn't upgrade if I could though. Mileage hasn't improved at all in the past 30 years, why bother to have something modern? More complications just means more stuff to break and more expensive to fix.

My original point wasn't about being diesel, but just about these older full size trucks having lots and lots of room for improvement.
He might not take all the exact same steps as I did, but I'm sure he can reach his goal and then some with out spending much and w/o any major mechanical changes.

I have 4.10 gearing Not sure how that affects things with the overdrive.

It is possible for me to do most of my driving at close to 35 mph or lower but I have to determine is it better to do lots of stop signs/lights or is it better to use the highway and do 55 with a lot fewer stops. With my old truck the highway was better so long as I made certain to keep it between 50 and 55 mph. 65 was enough out of the optimal rpm that I lost close to 30% the truck couldn't do 75 but I'm sure it wouldn't have been better.

Yes I definitely use it as a truck. 75% of it's miles since I got it have had a load in the bed. usually it's full of firewood so far but todays load is grass and dirt heading one way mulch coming back.

Thanks for all the suggestions so far. I'll keep an eye out for a vacuum gauge next time I'm near somewhere that will carry one.

highway
 

I find here in CA, land of the 12 lane superhighway, people are surprisingly understanding about me driving well below the speed limit, so long as I stay in the slow lanes

I have no overdrive, and I stop the engine at every stoplight, and I still get better mileage on the highway than on the streets...

but you never know, you'll have to try it to find out what works best for your particular vehicle.

Hi strider3700.

I see you're way up North where it will be cold in winter - and you don't put too many miles on the truck.

So I definitely agree with the person who posted earlier suggesting a block heater. Definitely a good idea. With a block that big you'll need to burn a bunch of fuel to warm it up - and you'll be burning most of that "warmup fuel" in open-loop mode, where the computer has it run rich because it's detected the engine is cold. Prewarming it electrically is way cheaper than doing it with fuel. The shorter your trips are, the more benefit you get from using a block heater. My commute is about an hour so I don't have one.

2nd topic - there's a big plus to running at non-highway speeds, as long as you can coast to stops. You'll find lots of past discussions here on the best way to do it with automatic or standard trans. Main point is, at highway speeds you're constantly fighting the aerodynamic drag which increases dramatically the faster you go. Up to about 40 mph the aero losses are almost insignificant and you can essentially pulse + glide the whole way, using the engine only when you need to increase speed.

With an automatic, you have to read the owners manual section on being towed, to learn what speeds you can coast at safely with the engine off. It varies with different trannies. If the engine is idling in neutral, most trannies will let you coast all you want. With the engine off there may be insufficient fluid flow and/or pressure to keep the tranny healthy, as the wheels are spinning the tranny internals. Of course if you kill it, you'll have to swap in a standard, which would be ideal!

I used to drive a boxy thing with automatic and lousy aero. NOT a Detroit iron beast. I got my Volvo wagon, EPA rated 17/22, up to about 30 mpg commuting on hilly limited access roads, in summer weather. I limited uphill speed to about 50-55, then goosed it after I crested the hill, got it up to about 70, put it in neutral and coasted down the rest of the hill with engine idling, as well as it would coast. Higher tire pressure helps your coasting.

Leave foot off the gas when slipping it back into Drive - that gave me the smoothest "shift". Rev-matching was pointless, it was much better going back into D at idle speed regardless of vehicle speed.

If you don't tow trailers much up your gearing to the 3.5 area and your FE will go up a bit on highway.

Because you have an automatic I can't recommend driving in areas with stop signs. Stop and go in an automatic is VERY difficult to get acceptable FE. On my dodge I have country-ish stop and go with hills and I can get the same as Highway fe by timing my coasting up the hills so I am down to a low enough speed to turn or stop.

Unless you can time your route perfectly in town so you never stop and tolerate coasting down to 12-18mph (normally) every time there is a stop or turn I can't recommend in town over highway. You can try it but it is very critical that you get everything mapped out and timed so you know exactly when to coast, accelerate, etc. One stop from a rather high speed can kill your FE for that entire trip. Different vehicles obviously respond differently to pulse and glide and in town driving, my dodge works OK but I need to glide up and down much more in speed than is normally acceptable and as I said one stop when I shouldn't be seems to kill my FE for the trip.

Good Luck
Ryan

Any updates on this? Wait for results.


Dan

It's funny I had been thinking about a post I need to do on here. My mileage has been crap, 10.5 - 11.5 when not 90% highway which got me 12.5 Loaded unloaded made zero difference. neutral at stops vs in gear made no difference. I've been compensating by driving the truck minimally. I swear I drive like grandma with a broken right foot but it's just horrible.

Anyways I got a clunk from the front end last weekend and noticed that when I first touched the brakes they seemed to be sticking so I went in to get the brakes looked at.

Long story short $3400 later I've got all new everything from the master cylinder down. The brakes where all partially sticking and one had just gotten worse that I noticed. I filled up 20 km before getting the work down. so far I've only put 220 km on it but just going by the gauge and the extra pickup the truck now has I'd say I should easily improve on my current average. I used to go 300-350 km on the front tank. The gauge says E at 250-260 normally. right now at 220 it's at half... So in a few more weeks when I fill up again I'll update the tracker on here and post an update in this thread.

I will note that I bought a scanguage and really really wish I had been able to use it. even thought the truck is a 97 it's not obd2. I still haven't seen a vacuum gauge while I'm out and about and haven't decided to order one in yet. my wallet is a lot lighter after the brakes...

Yeah it those gear in axle.

My F250 never gotten 11 or above. It exact one you have but it reg cab with flatbed.


Fun 96 E350 351W with 3.55 in axle got 16-17 on hwy but honest it little weak on hill couldn't use 2-3 gears it struggle Hill were 20-25% grade so it tough.

You could try is remove cat convetor I been heard reports improve 1-5 mpg by do that.


Anywhere I am replaced 95 F250 4wd with 91 F250 2wd so I could put 3.55 then able use truck for work.

Oh please. :mad:

Do you have proof answer that it doesn't improve mpg?


When it get old and that truck doesn't drive long enough it become plugged.


We just remove one on 91 Bronco and mpg from 14 went to 16 on HWY at same speed I go.

The point is removing a cat is illegal, and socially irresponsible. It's like winning a litter pick-up contest by dumping your garbage in everyone else's territory. You could remove your muffler, too. And drive with no lights on at night. All great fuel saving mods....

I answer proof all over site. :rolleyes:

Oh well how come I see tons 90's Chevy with TBI blow black smoke they should be banned.


cat convector on F350 is weight almost 30 pound it size of guard pole where people hit with car.



You could try unplug injector and see if it does improve mpg

OK, before things get out of control here
 

I for one am an advocate of replacing a plugged up cat with a free-er flowing model, but it still needs to be "legal" and do what it's made to do - clean the air coming out of the engine (had the same problem myself). Does it really improve FE, I don't really know.

My commute has now changed to half rural, half city driving vice 90% highway and I've still managed to improve mileage by re-teaching my right foot how to make my auto trans work for me.

I should have my scanguage next week, so I'm looking forward to more "foot training" as I learn what exactly my engine is doing.

I definately agree with the vacuum guage option, it kind of gives your right foot a conscience when you're trying to beat the clock getting somewhere.