I know there is a large wealth of knowledge here and im hoping to get some good ideas on how to improve the fuel economy on my suburban

its a 1993 K2500 Suburban with a 454
this means 3/4 ton and 4X4

i get about 9 to 10 mpg now on average

is there anything i can do to improve this?

my plans at the moment are cold air intake
tune up
and possibly some performance ignition parts...

What parts would you recommend?
What other ideas do you guys have?

I dont have the money to swap out the engine and i dont have the money to make it 2WD either, lol

this truck is rock solid and i dont want to get rid of it either if i can help it
just a 3mpg difference will add 120 miles or more to a single tank of gas so any improvement is going to help

she gets up to 16 on the highway but as soon as you hit the city streets it drops like the gas needle with the AC on ROFL
I would love to add multiport fuel injection to it, ive seen some nice kits for it but i dont have the 3 grand for the kit

so what can i do to improve city fuel economy?
thanks!!
Mack

Full tune up. Make sure tires are filled right and alignment is good. Maybe a tuner/chip. Remove any unnecessary weight. Change your driving habits. You'll never get stellar economy but in my old K1500 with a 350 and ext cab I was up to about 15 average when I tried. 11 when I didn't pay attention(usually)

i would saw a good tune will help a LOT. don't be fooled by all those "gimmick" products out there, most don't work.

other than the tune, check other things like tire pressure, make sure everything in the drivetrain is in good working order and well greased. when the bearing was going on my wife's G6, we noticed about a 4 mpg drop.

other than that, i guess just stay out of the throttle as much as you can

Tape a rotten egg to your gas pedal.

That and what has already been said above should help some. Remember you are driving 3 tons of empty truck around, it ain’t going to get good mileage in the city.

You can put this in 2 wheel drive can’t you? I mean this is not a constant 4 wheel drive?
You have the lever on the floor that puts it in and out right?

Drive it in 2 wheel when ever possible. I never put mine in 4 wheel drive unless the back wheels have started to lose their grip.

You have the ultimate vehicle for towing anything on the planet. Where are you Texas? I’ll trade you, our 94, 350 burban half ton 4X4.

I can actually use that truck to its potential.

Steve

------------------
Technology is great when it works,
and one big pain in the ass when it doesn't.
Detroit iron rules all the rest are just toys.

ooooo
let me think about that
thats a very interesting offer

i really am just using my truck to tow my boat this summer and carry people around

but at the same time this truck is my baby lol
i love this truck so lemme think about it

and yes, im in dallas

first things first... it's a truck so... front air damn front bumper. if you have some metal working skills may i suggest thin metal skid plates under the truck. A change in the front grill will make a large difference but you have to be careful not to go too crazy. don't restrict the radiator but removing some of the gaps will help with the drag.

If this is an auto trans then i would suggest a PROFESSIONAL trans filter change.

You don't have to go for a cold air intake just a short ram or K&N will suffice. With a cold air intake if not done right you run the risk of getting water in the intake on rainy days. Hope this helps. a few pictures would do us well for removing drag ideas

More air in, more air out (larger exhaust) skinny tires, high pressure. drive it like it'll break if you give it gas.

Disconnect the Power steering, perhaps put in an electric radiator fan.

Brad

good point about the muffler... if you don't need it remove the A/C and all of the components for it. Less weight.

Adjustable fuel pressure regulator will do wonders. It'll force better gas mileage. With all of what has been said here you could probably get it to 15+ a gallon

the regulator will allow you to turn down the pressure a bit when not in a towing situation and turn it back up for optimum output... worked on a 350sc

[This message has been edited by Finally_Mine_86_GT (edited 03-24-2010).]

I got a Idea... Send me that 454. I will send you a sweet running 350. Should in prove your Fuel Economy. J/K

quote Originally posted by yashmack: I know there is a large wealth of knowledge here and im hoping to get some good ideas on how to improve the fuel economy on my suburban its a 1993 K2500 Suburban with a 454 this means 3/4 ton and 4X4 i get about 9 to 10 mpg now on average is there anything i can do to improve this? so what can i do to improve city fuel economy? thanks!! Mack

Lame answer, I know... but the easiest way to save money on fuel is to feather the gas pedal when accelerating.

Some more technical ways of saving gas are:

1 - Exhaust headers. They might be expensive, but your engine will run much more efficiently, which will result in less fuel consumption.

2 - A Cold-air-Intake will help a little bit too, but not as much as the exhuast will.

3 - Higher flowing catalytic converters will allow the engine to also run more efficiently.

4 - Multi-port Fuel Injection. I assume you're running TBI right now? There's not a whole lot you can do with that. MPFI is really the best way to go. The 454 in those trucks, while huge, isn't the most efficient engine. Horsepower per liter is pretty poor. I'm not really sure why GM went in that direction, I think it was maybe to compete with the Ford Lightning? I don't know... but the motor really lacks efficiency. You need better flowing cyl heads, a drastically improved induction and fuel delivery system. All of what was available at the time, but I guess they didn't want to go through the trouble.


In the end, what it comes down to is that you have a big 4x4 truck with one of the largest Chevy big blocks available (not talking 572 crate motors obviously). There's not a whole lot you can do, and of course, spending a lot of money to improve fuel economy may be the wrong way to go about saving money. (Not being a smart-ass, but just laying that out there since I've been in the same situation).

Other things you can do of course is
- bump up the tire pressure to reduce rolling resistance
- Underdrive pulleys to reduce parasitic drag caused by reciprocating mass
- Install a tanneu cover to help prevent (somewhat) the air vortex that is created over the back when you drive.

Also... if you've never done it.. run a couple cans of Seafoam with a full tank of gas in your truck. This will clean out the carbon deposits which will undoubtedly improve fuel economy.

------------------
Todd,
2008 Jeep Patriot Limited 4x2
2002 Ford Explorer Sport 2dr 4x2
2002 Ford Crown Victoria LX
1987 Pontiac Fiero SE / V6
1973 Volkswagen Type-2 Transporter

I had one a few years ago, dually.

Ended up getting rid of it for gas mileage.... Its alot of motor to run on old technology.

I would go out and grab a LQ9 high compression 6.0 out of a late model and swap it in.

x2 with what TwoFatGuys said... I didn't even think about it, but by installing an electric fan to replace your mechanical fan, you'll see a significant fuel economy improvement in the city. At least 1mpg... I can almost guarantee it.

------------------
Todd,
2008 Jeep Patriot Limited 4x2
2002 Ford Explorer Sport 2dr 4x2
2002 Ford Crown Victoria LX
1987 Pontiac Fiero SE / V6
1973 Volkswagen Type-2 Transporter

9-10 mpg doesn't sound too bad for that truck. I'd do a standard tune up.

My father had a 1986 Chevy C30 truck with a 454 the only thing that it didn't pass was a gas station. Empty or loaded it got 6.5mpg. After two years of owning the truck we found one of the two gas tanks was leaking. We replaced the tank for safety reasons and to get better milage. After replacing the bad tank the truck got 6.5mpg.

454 engines are thirsty, plain and simple. Some of the newer big blocks (8.1L )are better on ecomomy.

As stated above, a good tune up with quality plugs, cap/rotor, wires, O2 sensor and fuel filter.

A hot air intake will also improve MPG due to lowering pumping losses (I saw a 1 mpg decrease with a cold air intake on my SBC). On large engines, cold dense air at crusie speeds just means the throttle blades will be closed further and you will be pulling more vacuum. The hotter less dense air keeps the throttle blades open further, yeilding less manifold vacuum and results in less pumping losses.

Then move on to cleaning the EGR and all the ports... this is very important on large displacement engines - same pumping loss issue.

Check the injector spray pattern to make sure it is spraying not dribbling - might be worth cleaning the injectors.

If you are not planning to do any heavy towing for a while, bumping the ignition timing a couple degrees could help as well - it is best if you have a scanner or other means to check for spark knock while doing this.

Then on to the brakes, wheels and tires. Check to make sure the brakes fully release and do not drag. Check the wheel bearings for smooth spinning and make sure the tires are properly inflated. An alignment to ensure the least amount of resistance would also be good.

The 4x4 system - the newer models have clutches to minimize the spinning parts when in 2wd... look for options to reduce the number of unnedded parts that are just spinning around needlessly.

Weight reduction... take out anything that is not needed...

Readup on hypermiling driving techniques... heavy vehicles see a greater benefit from this.

[This message has been edited by fieroguru (edited 03-25-2010).]

My 2000 6.0L 2500HD with 4.10's gets 12.5 average and I've seen 14 on the freeway. In town? Don't ask. I know the 8.1L gets about 10-12 tops.

Your 454 is pretty much in line with reality. You can get slightly better mileage by spending a lot of money but you have to calculate how much gas you could buy for the cost of headers, intake, etc. for the life of the truck.

You might do a search and see if that ECM supports lean cruise and if anyone makes a chip that enables it. I know the 7747 does, I don't know if the 8747 does (and I don't know what ECM is in the 93 7.4L. You might gain 5% on the highway but it won't kick-in around town (so no help there.)

But in the end, I doubt you will wring much more out of it and still be cost effective.

quote Originally posted by TK: My 2000 6.0L 2500HD with 4.10's gets 12.5 average and I've seen 14 on the freeway. In town? Don't ask. I know the 8.1L gets about 10-12 tops.

I have the same truck, a little newer, a little higher, a little bit bigger rims and tires, and my fuel mileage is 10 on the highway.

Cold air intake will reduce fuel economy. Denser air requires smaller throttle openings for the same power output, creating high pumping losses.

If anything, get a round exposed air filter on top of the engine like classic cars have. Might be worthwhile.

Adding $3000 worth of multi-port fuel injection equipment on the other hand; I doubt it would pay for itself.

[This message has been edited by pmbrunelle (edited 03-25-2010).]

People generally dont care about fuel economy when they buy 454s

Is it carbed ? If so, disabling the secondaries will save a few mpg on highway. Just running on a 4bbls primaries will save gas because there smaller than a 2 bbl. Obviously, youll have to give up some performance. Depending on carb its simple to do. Mechanical secondaries only need a small piece of linkage removed. Vacumm just needs hose plugged off. If its FI, pretty much have to live with what you got after a good tune up.

Im almost done putting my 413 in my Coronet. Gas mileage is not one of my priorities,

the muffler is a very large restriction. I had a 93 350 tbi suburban 2wd and I imroved the highway mileage by 2 mpg by changing the muffler. I used a walker dynomax, I don't remember the part # but it was 3" inlet 3"outlet 8 3/8 round and 34" long. It was for rv's but it was almost identical to the 350 suburban muffler. cut it as close to the body of muffler as possible and clamped it on. GM voluntarily passed a 30mph drive by noise test, it was optional back then, had to put more baffling in the muffler to pass db test. My stock muffler reduced down in size to 2 1/4" in the factory muffler. Walkers is 3" all the way through. The rest of the factory exhaust was already 3" , so you just change muffler. it was only slightly louder than factory but it had a deeper sound. I think because of the large size that is why it was quiet. I did this muffler on 2 mid 90's gm c/k 350 trucks and I got the same 2 mpg on the highway on them both. I also had jacobs ignition coil , module and wires, rapid fire sparkplugs and some of the parts from Turbo City, tbi spacer, large tapered funnel instead of the riser between air cleaner and throttle body. Truck ran really well especially pulling our 5500lb travel trailer. I also changed all the oils and lubes to synthetic, supposed to cut friction. Our 93 suburban got a couple of tanks at 22 mpg to and from florida, driving only 5mph over the speed limit and driving very conservatively. Even with 3.73:1 axle it did well at freeway speeds. City never change much from 12-15, depending on the time of year and traffic.

I just got a new car stuff catalog. They have a thing in there that plugs into your cigarette lighter and has a pretty green and red led. It claims to give you 20% more gas mileage by 'cleaning up' any electrical interference thats affecting your fuel injection or ignition system. Its only $29 too. .............ROFLMAO

On the highway running 70 mph (cruise set), I get 12 mpg in 4 high and 15 mpg in 2 high with my 95 GMC Z-71, 350, EFI, automatic, extended cab. 200,000 miles, did a full tuneup 2 years ago when I bought it, and put a Jegs 3" into a pair of 2.5" catback on it last summer. No change in the mileage with the new catback, so either my OEM cat is the blockage, or it just doesn't matter. Stock sized tires, 40 # and 35 # per the door sticker. 5W-30 oil.

Lucky to get 10 mpg arouind town, in either 4 high or 2 high.

quote Originally posted by 2birds: On the highway running 70 mph (cruise set), I get 12 mpg in 4 high and 15 mpg in 2 high with my 95 GMC Z-71, 350, EFI, automatic, extended cab. 200,000 miles, did a full tuneup 2 years ago when I bought it, and put a Jegs 3" into a pair of 2.5" catback on it last summer. No change in the mileage with the new catback, so either my OEM cat is the blockage, or it just doesn't matter. Stock sized tires, 40 # and 35 # per the door sticker. 5W-30 oil. Lucky to get 10 mpg arouind town, in either 4 high or 2 high.

That has to be wrong. No one drives 70 MPH in 4 wheel drive. If you do you are out of your friggen mind. 4 wheel drive is for when conditions require extra traction on slippery roads. If you are driving 70 MPH in 4 wheel drive you better be driving an ambulance. Because you are going to need one real quick.

Sorry if that sounds harsh but it is not the smart thing to drive like that.


Now this I have never heard of, and don’t believe. More air is always good for mileage from what I have always been told.

quote Originally posted by pmbrunelle: Cold air intake will reduce fuel economy. Denser air requires smaller throttle openings for the same power output, creating high pumping losses. If anything, get a round exposed air filter on top of the engine like classic cars have. Might be worthwhile. Adding $3000 worth of multi-port fuel injection equipment on the other hand; I doubt it would pay for itself.

Steve
------------------
Technology is great when it works,
and one big pain in the ass when it doesn't.
Detroit iron rules all the rest are just toys.

[This message has been edited by 84fiero123 (edited 03-26-2010).]

A short ram or K&N is the best way to go for an intake anyway. I've seen a badly installed cold air completely destroy an engine. There are humidity traps that need to be there. It's a small fortune for the good ones and the gain is just not worth it.

quote Originally posted by 84fiero123: Now this I have never heard of, and don’t believe. More air is always good for mileage from what I have always been told. Steve

Do you believe that leaner than stoichiometric mixtures help with mileage?
Or exhaust gas recirculation?

Both of these techniques also work by reducing power output for a given throttle opening, requiring the driver to open the throttle butterfly more to maintain the same power, reducing pumping losses.

By pumping loss, I mean the power wasted because the engine has to pump air through the partially closed throttle.

[This message has been edited by pmbrunelle (edited 03-26-2010).]

I read in a 4x4 magazine that if you remove your front drive line it will give you about a 1 mpg increase. The theory is that it will reduce spinning dead weight. I have never done it before, but it doesn't sound like a bad idea.

[This message has been edited by DeLorean00 (edited 03-26-2010).]

My mom has a 4WD Suzuki Sidekick.

In 2WD mode, the transfer case disengages the front driveshaft, and the driver unlocks the front wheel hubs.

This way, the front half-shafts, differential, and driveshaft don't rotate in 2WD.

I'd assume most part-time 4WD systems before the era of electronic nanny-control viscous clutch crap operate like this. Then again, the reason for the nanny-controls is that most people can't drive, and do things like drive in 4WD on pavement.

It does make a noticable difference in drag. For example, when letting off the throttle (free-wheeling automatic tranny), the Sidekick will coast a quite a bit longer if the front section of the drivetrain isn't rotating, compared to the situation with the front hubs disengaged, but the transfer case in 4WD (which is effectively 2WD, but spinning the front section of the drivetrain needlessly).

[This message has been edited by pmbrunelle (edited 03-26-2010).]

all very good information, thanks alot guys!!
looks like a free flow cat (or no cat... >.> HC and NOx requirements are extremely high for this engine here in tx... hehehe) and a bigger exhaust is going to help alot
the cat may be a little blocked on it now according to my mechanic so that will be removed/replaced soon...

a short ram intake is definitely something i want but its hard to find one
Autozone sells all the parts to make your own intake so i may look into that
I need to figure out how to keep water out of it though...

i will be doing a full tune up on it asap
and the tires on it are stock and inflated to at least 50psi (80 is the max)

i am kind to the throttle, it does not take much to get this truck moving...
push the throttle half an inch and it will MOVE hehe

would upgrading the ignition to hotter coil help as well?
what is a good brand to use if so?

now to find a good exhaust shop...

quote Originally posted by yashmack: all very good information, thanks alot guys!! looks like a free flow cat (or no cat... >.> HC and NOx requirements are extremely high for this engine here in tx... hehehe) and a bigger exhaust is going to help alot the cat may be a little blocked on it now according to my mechanic so that will be removed/replaced soon... a short ram intake is definitely something i want but its hard to find one Autozone sells all the parts to make your own intake so i may look into that I need to figure out how to keep water out of it though... i will be doing a full tune up on it asap and the tires on it are stock and inflated to at least 50psi (80 is the max) i am kind to the throttle, it does not take much to get this truck moving... push the throttle half an inch and it will MOVE hehe would upgrading the ignition to hotter coil help as well? what is a good brand to use if so? now to find a good exhaust shop...

I think you are wanting a bad exhaust shop. The badder, the better.

Brad

nah, round here they usually just do what you tell em

quote Originally posted by yashmack: I know there is a large wealth of knowledge here and im hoping to get some good ideas on how to improve the fuel economy on my suburban its a 1993 K2500 Suburban with a 454 this means 3/4 ton and 4X4 i get about 9 to 10 mpg now on average is there anything i can do to improve this? Mack

I had to let you know
http://sydney.gumtree.com.a...l-W0QQAdIdZ159751926

it does work
Now shipping to the philipines+Holland+UK+NZ and all states in Australia

[This message has been edited by proff (edited 08-03-2010).]

efi swap. will get you upwards of 25mpg

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Cliff's 610th Positive Feedback Giver.

quote Originally posted by 82-T/A [At Work]: x2 with what TwoFatGuys said... I didn't even think about it, but by installing an electric fan to replace your mechanical fan, you'll see a significant fuel economy improvement in the city. At least 1mpg... I can almost guarantee it.

For the cost and work involved, it will take a long time to recover the cost at 1mpg. I still on the fence about electic waterpumps. I just dont take them as being that reliable on a street car...but excellent choice for a race car.

quote Originally posted by Hockaday: efi swap. will get you upwards of 25mpg

My truck has EFI, its a TBI fuel injected engine
what are you referring to?

quote Originally posted by Hockaday: efi swap. will get you upwards of 25mpg

Not a hope.

I think he meant MPFI. Maybe... And, yeah, no chance in hell. If GM could make a big block pickup get 25 mpg they'd getting 50+ out of all their normal cars.

Here's what I have done in my 83 F250 4x4. I got a 408W,9.3 cr, GT40P heads, dual 2.5" exhaust, x pipe, 4 bl carb, RPM Air gap, manual 4 spd, no OD, 4x4 cam. I get 14 mpg average ,15 highway. If I had an OD trans and TPI or SFI I would be close to 20 mpg. To your issue and If money isn't a concern I'd put in a stroker 502, SFI, OD trans , maybe a taller gear, electric rad fan, cold air intake, the highest CR you can get by with, a good low rpm torque cam, dual 3' exhaust, headers. You should be able to idle up hills with a load. But you can buy alot of gas for what this would cost. Wish I would have done more research before I done mine.

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85 GT 3.4
14.9 @ 90 1.9 60' Old TH125/3.06
Unknown New 4T60/3.42

With my 99 K2500 Suburban 454 I get 10-11 empty, 10-11 towing, I think it gets 10-11 sitting in my driveway. I thought of a gear vender overdrive but it would take forever to pay for it with gas savings. I just suck it up when I fill up the 44 gal tank and be glad I have it when I need it as it sure is nice when I need to pull 9-10k lbs.

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Hop Till You Drop!!
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86 GT " Snapperhead" .. Lambo Doors, ZZ4 FI 350, 5sp, Car pc, Laser Blue
87 GT "Whipersnapper" .. 2.8, Auto.. Planning a LS4 Conversion
88 Formula.. 2.8, Auto, Stock, White... Wife Ride
85 Gt Black, 2.8, 4sp, Lowered and ready for paint.
99 K2500 Suburban, 454, 4X4, The Tow Rig
04 Trailblazer, 4x4, Green, Wife Ride

quote Originally posted by Snapperhead: I think it gets 10-11 sitting in my driveway.

I have never read a more accurate statement.

I had a Lincoln 460 that used a ¼ of a tank of gas to go to the beach, or around the corner to get a pack of smokes.

quote Originally posted by Hockaday: efi swap. will get you upwards of 25mpg

Read my first post on the subject.

quote Originally posted by 84fiero123: Tape a rotten egg to your gas pedal. Remember you are driving 3 tons of empty truck around, it ain’t going to get good mileage in the city.

Steve

------------------
Technology is great when it works,
and one big pain in the ass when it doesn't.
Detroit iron rules all the rest are just toys.

[This message has been edited by 84fiero123 (edited 04-13-2010).]

I've got a ' 91 Suburban with a 350 and I get 12-13 on the highway dead empty. That's with new tires at the top pressure and just me in the truck. If you can beat that with a 454, I'm getting myself a 454 for better mileage.

There are many good suggestions above. You can also try lowering the suspension to get better aerodynamics. Get rid of any roof racks or large rear view mirrors. Don't use any off road tires and remove as much weight as you can. You can also get an overdrive that attaches to the end of the transmission and gives you a better gear ratio. Here are a couple of articles for you to read.
http://www.chevyhiperforman...fications/index.html
http://www.high-impact.net/...rive_conversions.htm