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Improving Fuel Economy
- Thread starter kis2
- Start date
Jessie James
1/2 ton status
I bet you can't hear the gas gauge suddenly moving towards empty either! 
smier
1/2 ton status
I have had a couple cars with the realtime fuel mileage computers, and he is right. I have found I get my best fuel mileage between 55 and 60 mph on the highway In almost every vehicle I've ever owned. I tow primarily with the Durango, and on road trips doing 70+ mph I have averaged around 16 or 17 mpg, I get almost the same mileage towing my loaded down camper or my sailboat at 58 mph averaging 15 to 16 mpg... Now, I have also gotten as high as 20 mpg average on flat highway with the whole family and gear in the Durango drafting vehicles in front of me and keeping it under 60 mph.
I drive tractor trailers for a living, so I've gotten pretty good over the last 17 years squeaking out as many mpg as possible. When it costs you almost $1200 to fill up, and your rig is only averaging a little over 7mpg and you average 500 to 600+ miles a day,you start paying attention to every way you can save a few bucks.
I bet you can't hear the gas gauge suddenly moving towards empty either!
I don't need to hear it, cause i can see it move towards empty
Then again, you are talking to a guy that has seen the average MPG in his BMW hit single digits on a 30 min drive.....
So yes, driving style and speed is one of the major contributors.
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Last time I checked, my 4" lifted m1009 with 37" hummer tires and stock gearing got around 19mpg mostly highway miles. So yeah, diesel swap is probably the only way to increase your mpg much at this point
1987 305 TBI - 700R - 3:08 axles - 31 gallon fuel tank
I have the duals from LMC with the turbo style mufflers no cats. TBI spacer and K&M ail filter. I am running 10/30 Q-power synth summer and 5/30 in winter. I get 13 mpg around town and average 18mpg on highway running about 68mph. By realy babying it I could squeeze 21 on highway at 55mph. As said take it nice and easy from stops drive like you have a raw egg under the pedal.
I let the truck slow as I go up hills (in other words keep same pressure on pedal as on flat). I also keep tires up to the max per tire maker. I also try to avoid ethanol gas it gets lower mpg.
This all came to facts from the 6600 mile thirty day bucket list trip I did a few years ago and gas was $4.55 a gallon.
I have the duals from LMC with the turbo style mufflers no cats. TBI spacer and K&M ail filter. I am running 10/30 Q-power synth summer and 5/30 in winter. I get 13 mpg around town and average 18mpg on highway running about 68mph. By realy babying it I could squeeze 21 on highway at 55mph. As said take it nice and easy from stops drive like you have a raw egg under the pedal.
I let the truck slow as I go up hills (in other words keep same pressure on pedal as on flat). I also keep tires up to the max per tire maker. I also try to avoid ethanol gas it gets lower mpg.
This all came to facts from the 6600 mile thirty day bucket list trip I did a few years ago and gas was $4.55 a gallon.
kis2
1/2 ton status
I'm normally pretty gentle on the gas pedal, especially while trying to baby the new tires. I used to get around 18 with my 305 and stock sized tires.
Think and K&N air filter would be a worthwhile upgrade, long run?
How about TBI?
Think and K&N air filter would be a worthwhile upgrade, long run?
How about TBI?
Sweet rig.....
I have a 350 TBI and only get about 8 mpg. But it's pretty much a tank.
And since I didn't buy mine for the milage I just live with it and enjoy it as much as I can. One day.
I'm also learning how tune my own chip so hopefully I can gain some better mpg then. If not, oh well. I'll just carry extra gas if needed.
I have a 350 TBI and only get about 8 mpg. But it's pretty much a tank.
And since I didn't buy mine for the milage I just live with it and enjoy it as much as I can. One day.
I'm also learning how tune my own chip so hopefully I can gain some better mpg then. If not, oh well. I'll just carry extra gas if needed.
Nah eff that, I like making my blazer do this, both at the dunes and in town. Its worth the $4 a gal.
PS if you turn your speakers up you can tell why I like it
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Glad you made it back!
A freind of mine bought a 1986 Carbed 454 Crew Cab dually to town his car trailer loaded and cab over camper when he moved from Idaho to Texas. He got 1.2 MPG... gross weight was over 18K...
kis2
1/2 ton status
...1.2mpg...they need a smilie for 'weeping uncontrollably'.
thanks wheels87k5! I've put a lot of time and work into it, make sure to check out the build thread
thanks wheels87k5! I've put a lot of time and work into it, make sure to check out the build thread
I find the best way to save gas in any vehicle,is to just stay home...
...sorry,but thats the truth!---in a truck weighing 3 tons with the wind reststance of a brick,you cant expect to get over 15 mpg no matter what engine you have...even my diesels rarely get more than that ,just putting around town with no load to speak of..................................................................................................................................................................................................................for those who must drive,all we can do is pray for lower fuel prices,keep our tires inflated to maximum pressure,and drive like your gas pedal wont go past 1/8th throttle,and back off the gas as soon as you get up to the speed limit,its surprising to see you can maintain a certain speed with much less throttle ,or keep your foot in it more,and still go no faster...coast down hills as much as possible,dont use the brakes unless its imperative,and resist the urge to pass people going slower than you like.....................................................................................................It's getting to the point buying a smaller more efficient vehicle to cruise around in is worth it...we dont need a full sized truck to get groceries or go to a movie,out to eat,etc...but unfortunately registering and insuring another vehicle will cost a lot,the sales and excise taxes will add up too--all that money could buy quite a bit of gas...
...sorry,but thats the truth!---in a truck weighing 3 tons with the wind reststance of a brick,you cant expect to get over 15 mpg no matter what engine you have...even my diesels rarely get more than that ,just putting around town with no load to speak of..................................................................................................................................................................................................................for those who must drive,all we can do is pray for lower fuel prices,keep our tires inflated to maximum pressure,and drive like your gas pedal wont go past 1/8th throttle,and back off the gas as soon as you get up to the speed limit,its surprising to see you can maintain a certain speed with much less throttle ,or keep your foot in it more,and still go no faster...coast down hills as much as possible,dont use the brakes unless its imperative,and resist the urge to pass people going slower than you like.....................................................................................................It's getting to the point buying a smaller more efficient vehicle to cruise around in is worth it...we dont need a full sized truck to get groceries or go to a movie,out to eat,etc...but unfortunately registering and insuring another vehicle will cost a lot,the sales and excise taxes will add up too--all that money could buy quite a bit of gas...lovebomb_69
Registered Member
Here in Missouri all our gas is 10% ethanol minimum. if i fill up with the cheap stuff im at the pump more than if i fill up with premium.
There's a lot of truth in more MPG with premium! In EFI equipped vehicles!
Jessie James
1/2 ton status
Reducing intake constriction is good, but it won't help much.
TBI is much more efficient than carb, but the cost to swap probably nullifies your investment, unless you sell your truck and buy a TBI one.
No, that has been debunked many times. Premium fuel basically only has more octane. Octane is a knock/pre-ignition inhibitor. You only need more octane if you have a high compression engine or forced induction. High compression leads to pre-ignition and knocking which obviously causes massive damage. That is why turbocharged, supercharged, and high compression cars all require premium. Anything else and you are wasting money, and if the point is to spend less money on gas and go father you're making an expensive mistake. In a car that requires premium, with an ECU computer, if you put regular gas in then the ECU will detect knock and retard the timing to prevent that knock, which then kills efficiency so you get worse MPG.There's a lot of truth in more MPG with premium! In EFI equipped vehicles!
Google it: http://ask.cars.com/2007/07/premium-gasolin.html
Agent_Orange
1/2 ton status
yeah.... good luck with that 
. we drive these trucks over rocks, threw mud and rivers, up mountains and down ravines, over downed trees every other thing mother nature drops on the ground. they are as areodynamic as a cinder block and wiegh more the 3 priuses added together= bad MPG.
good MPG=motorcycle
. we drive these trucks over rocks, threw mud and rivers, up mountains and down ravines, over downed trees every other thing mother nature drops on the ground. they are as areodynamic as a cinder block and wiegh more the 3 priuses added together= bad MPG.good MPG=motorcycle
big pappa b
3/4 ton status
The K5 I just brought home gets 12.5 mpg. 6" lift on 37's, 1 tons w/4.56's and detroits. Motor is stock 350 TBI motor. Not great but I've drove worse.
Didn't have time to read article but if it is backing up what your saying it is wrong for EFI! Correct for a carb if you don't increase timing. Premium fuel will also allow more timing, ECM checks timing with forced knock test. Newer then these ECMs are even better at this.
The premium will only increase MPG on highway cruises, does not help in town.
Add a HighWay Lean Cruise Patch to your chip (bin) and a little tweaking to tune and I added 20% highway MPG!
Jessie James
1/2 ton status
If you're getting exceptionally bad MPG, at the very least be sure the basics are all correct.
Things like...
Proper thermostat - this is crucial. If you are running too cold (160 carb, 180 TBI) then your engine never reaches proper operating temps. This means significantly worse efficiency and bad MPG. It's like driving with your choke on all the time. It also causes breakdown in the oil and other issues that cause premature engine wear. More
Intake that draws cooler air from outside of the engine bay (usually via the snorkel tube). Cold air is more dense than warm air. Therefore, cold air holds more oxygen and hot air holds less oxygen. Oxygen is what burns. If you want better performance, get more oxygen into the engine (like a turbocharger) that is cooler. Why draw in air that is 200 degrees when the outside air is 100 degrees cooler? That is why intercoolers are often used on forced induction engines - they increase efficiency and thus performance.
Proper type, reach, and heat range spark plugs. Running too hot or too cold means poor efficiency.
Good spark plug wires. Restrictive wires mean less power.
Good coil. Is your coil giving 50% power? You are losing efficiency.
Good cap & rotor. Corrosion means less power to the spark plugs.
Engine is correctly timed.
Brakes are adjusted properly and are not dragging (parking brake, drum brakes).
Alignment is correct. Out of alignment could mean improper toe-in, toe-out, caster/camber, or other issues that increase the force required to push you down the road. That of course could also cause tire wear as a by-product.
Tires are properly inflated. Skinny, smaller, hard tires get better mileage that wide, giant, or soft tires.
Driveline bearings are not excessively worn, are properly lubricated.
Exhaust is not too small, restrictive (clogged, kinked, worn catalytic converter), and also not too "open" (too large diameter tubing). Exhaust backpressure is VERY important because it helps "scavenge" (pull) exhaust gases from the cylinders by "sucking" it out. If you have an improperly sized exhaust, you lose this benefit and reduce efficiency. In addition, an exhaust system that is too large allows the exhaust to cool quickly, before being expelled, and that in turn can reduce flow efficiency. You want to have the exhaust exit quickly and smoothly.
Stock exhaust manifolds are typically very restrictive. If you can get equal length headers (to maintain proper backpressure and exhaust scavenging) that can help tremendously.
Rebuild your carb and replace the jets, check the float levels, and clean out any crud that may have clogged orifices.
Check emissions equipment, such as the EGR, which may be blocked and causing you to burn more fuel. As much as people hate emissions equipment, some equipment can dramatically improve efficiency and MPG.
Check that other engine sensors are working properly if you have a TBI engine. A defective temp sensor or MAP sensor can incorrectly tell the computer to operate at the wrong settings, wasting fuel.
Replace TBI fuel injectors if they are very old.
....
Remember something else - automotive engineers have nearly 100 years of experience with vehicles, and probably have at least 4-8 years of education, plus a few years of on the job training. It always makes me laugh when someone buys a car and rips out the intake system and puts in an open-element filter that sucks in hot air from the engine bay, rips out emissions equipment, puts on a different muffler or cat-back system that is "louder" and then says they get better performance. What in the world makes these people think they are smarter than thousands of engineers that have computers and have tested millions of configurations? Most cars made from the 60's and on have the best efficiency and power available at the time. It's so incredibly unlikely that anything aftermarket will make more power it boggles me.
If you want to read an amazing book, read Maximum Boost by Corky Bell.
Things like...
Proper thermostat - this is crucial. If you are running too cold (160 carb, 180 TBI) then your engine never reaches proper operating temps. This means significantly worse efficiency and bad MPG. It's like driving with your choke on all the time. It also causes breakdown in the oil and other issues that cause premature engine wear. More
Intake that draws cooler air from outside of the engine bay (usually via the snorkel tube). Cold air is more dense than warm air. Therefore, cold air holds more oxygen and hot air holds less oxygen. Oxygen is what burns. If you want better performance, get more oxygen into the engine (like a turbocharger) that is cooler. Why draw in air that is 200 degrees when the outside air is 100 degrees cooler? That is why intercoolers are often used on forced induction engines - they increase efficiency and thus performance.
Proper type, reach, and heat range spark plugs. Running too hot or too cold means poor efficiency.
Good spark plug wires. Restrictive wires mean less power.
Good coil. Is your coil giving 50% power? You are losing efficiency.
Good cap & rotor. Corrosion means less power to the spark plugs.
Engine is correctly timed.
Brakes are adjusted properly and are not dragging (parking brake, drum brakes).
Alignment is correct. Out of alignment could mean improper toe-in, toe-out, caster/camber, or other issues that increase the force required to push you down the road. That of course could also cause tire wear as a by-product.
Tires are properly inflated. Skinny, smaller, hard tires get better mileage that wide, giant, or soft tires.
Driveline bearings are not excessively worn, are properly lubricated.
Exhaust is not too small, restrictive (clogged, kinked, worn catalytic converter), and also not too "open" (too large diameter tubing). Exhaust backpressure is VERY important because it helps "scavenge" (pull) exhaust gases from the cylinders by "sucking" it out. If you have an improperly sized exhaust, you lose this benefit and reduce efficiency. In addition, an exhaust system that is too large allows the exhaust to cool quickly, before being expelled, and that in turn can reduce flow efficiency. You want to have the exhaust exit quickly and smoothly.
Stock exhaust manifolds are typically very restrictive. If you can get equal length headers (to maintain proper backpressure and exhaust scavenging) that can help tremendously.
Rebuild your carb and replace the jets, check the float levels, and clean out any crud that may have clogged orifices.
Check emissions equipment, such as the EGR, which may be blocked and causing you to burn more fuel. As much as people hate emissions equipment, some equipment can dramatically improve efficiency and MPG.
Check that other engine sensors are working properly if you have a TBI engine. A defective temp sensor or MAP sensor can incorrectly tell the computer to operate at the wrong settings, wasting fuel.
Replace TBI fuel injectors if they are very old.
....
Remember something else - automotive engineers have nearly 100 years of experience with vehicles, and probably have at least 4-8 years of education, plus a few years of on the job training. It always makes me laugh when someone buys a car and rips out the intake system and puts in an open-element filter that sucks in hot air from the engine bay, rips out emissions equipment, puts on a different muffler or cat-back system that is "louder" and then says they get better performance. What in the world makes these people think they are smarter than thousands of engineers that have computers and have tested millions of configurations? Most cars made from the 60's and on have the best efficiency and power available at the time. It's so incredibly unlikely that anything aftermarket will make more power it boggles me.
If you want to read an amazing book, read Maximum Boost by Corky Bell.
