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Improving Fuel Economy

kis2

kis2

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Gas prices the way they are :doah:, this must be on some other daily-drivers minds. But even for more purpose built vehicles, longer legs are a good thing.

So my question is: What are somethings your average K5 can do to see better gas mileage? Even a little bit here and there can add up to a couple MPG. Little and big suggestions welcome.

Thanks for the suggestions!
 
What are you getting now?

Big lift, big tires, large motor, numerically high gears are going to equal worse mileage, but if you drive 80MPH with a stock truck your mileage might be worse than the guy driving the aforementioned truck at a more modest speed.

Just a rough worst case number for a pretty "stock" truck, if you are getting under 10MPG city and/or under 15MPG highway you might be doing something wrong.

The only way to get "good" mileage out of one of these trucks is the 6.2L diesel, or at least that's the highest I've ever seen from a fairly standard drivetrain. I think that was 25MPG highway from TrustyK5.
 
Clean air filter, clean fuel filter, and properly inflated tires.

From there, small gains can be made with a free flowing exhaust.

Other than that, keep your foot out of it :)
 
This topic is always of interest to me, especially with gas prices.

My burb is only getting 10 mpg in town, it has BF Goodrich Mud-terrain tires, I'm guessing that big ol nobby tires cut down on gas mileage. Swapping tires to a highway tire would probably save some gas, but then these tires are in pretty good shape and new tires would be a bundle.
 
Macumazahn said:
This topic is always of interest to me, especially with gas prices.

My burb is only getting 10 mpg in town, it has BF Goodrich Mud-terrain tires, I'm guessing that big ol nobby tires cut down on gas mileage. Swapping tires to a highway tire would probably save some gas, but then these tires are in pretty good shape and new tires would be a bundle.
Click to expand...

Tire tread is definitely a part. In our short length ownership of a Camery Hybrid.....with stock tires she was getting like 40 MPG. When we put on the studded tires (same size) all the way around, it instantly dropped down to 35 MPG! I couldn't believe it really, until the summer tires went back on and the next tank--back up to 40.

Now, wouldn't 35 mpg be sweet with a Gasser K5!! :waytogo:
 
Rolling resistance is big, and a big contributor to that is tire width.

Narrow tires offer significantly less rolling resistance in my understanding.

Going for 235's to 12.50's sure didn't help my mileage!
 
I know a lot of people don't like the width, but economy was one reason I went with the 33x10.5R15's.
 
jeff in co said:
Tire tread is definitely a part. In our short length ownership of a Camery Hybrid.....with stock tires she was getting like 40 MPG. When we put on the studded tires (same size) all the way around, it instantly dropped down to 35 MPG! I couldn't believe it really, until the summer tires went back on and the next tank--back up to 40.

Now, wouldn't 35 mpg be sweet with a Gasser K5!! :waytogo:
Click to expand...

When I went from 31" street tires to 32" Goodyear Mud Terrains, it cost me almost 2 mpg instantly. A big contributor to fuel mileage drop in the winter is the winter blend fuels in some parts of the country, they will drop your average fuel economy by 10 percent or more.
 
This question is always on my mind regarding my Chevy based RV. Things I think about are changing the gear ratio, changing the carb and intake manifold, switching to TBI, or changing to a 700R4 with overdrive. When I put 4000+ miles on it this spring, I averaged 8.3 miles per gallon. I would be happy getting at least 10 miles per gallon.
 
I kinda left the question vague so that people would make suggestions that might not fit my situation, but may help others. but my situation is I have a 700trans (so the OD does some good work for me), I can't recall which edlebrock model carb I put on but it was midrange for consumption. new filters all around. stock 350. I'm putting on an aluminum radiator right now to see if having it run a little cooler will help.

here's a pic of the beast, check the build thread for more. as you can see though, there are super easy ways I could save some weight (like no giant bumpers or 3/4ton axles), but I'm keeping them :rolleyes: ...I recently got new tires, went with the duratracs. they are still big (35x12.5 on a 16), but not sooo aggressive that they kill me on the highway. the biggest reason I have a softtop is to try and save some weight.

currently, with about a 70%/30% of highway/city driving mix, I get a reliable 13.7mpg. but a guy can always stand to save more money. we all obviously accept some of this just to drive one of these sweet machines. still, as bad as it is, everytime I run the numbers for my situation its way cheaper than buying a new 4x4!

is a K&N filter a worthwhile upgrade over something like fram?

keep up the tips!

IMG_2359.jpg
 
Lol, 13.7 mpg. I get half that. Quit yo bitchin!!!! :haha::haha:


Im sure TBI would help alot!
 
Sweet rig. I'd be lucky if I got 7-8 mpg. Hell, my wife's brand spanking new Acadia gets about 17 mph. I'm just glad I have a 40 gallon tank, or more.
 
I would love a bigger fuel tank. It's got the 31 gallon, but if I could go bigger I would.

I was looking at (sacrilege I know) a jeep or a midsize pickup with 4x4 if I opted not to fix up the blazer but then I did the math: 14mpg blazer, 18mpg jeep, say 15miles a day and $3.50/gallon = like less than a dollar a day in gas savings. but you get a loan payment and more expensive insurance with the new truck. screw that.

I have a buddy with a titan with 35" tires, but they apparently don't have the gears for those axles to support those tires yet. dude gets like 8mpg.

thanks for the compliment munepit! someday I hope it makes the front page of ck5, but that's a pretty competitive race! I keep an eye on your build thread, very sweet.
 
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it has been mentioned... for they heavy and modded trucks you wont get any better millage......still good spark plugs/wires, coil and id try a spark box.
 
13.7 with that rig is about as good as it's gonna get I'm afraid...

Unless you want to swap in a 6.2 diesel. I could average 16.5mpg on the highway running 4.56's 39.5" TSL's and no overdrive. My C1500 averages 23.5+ mpg on the highway and I have seen 25...

Neither one will help you pick up chicks or impress anyone stoplight to stoplight though.
 
Check my math, but if you multiply your 13.7 number by 30%, you come out to 17MPG. You aren't getting better than that without a diesel. That's as high as I've ever seen save one instance going downhill for about 10-15 miles where I shut the truck off, and got 18MPG.

Truck scaled at 5000lbs (gravel yard scale). 305, Quadrajet that worked right, 700R4, 3.08's and 31" tires at 50MPH, flat ground, cool desert air at night, 17MPG.

Cooling the engine off or more air isn't going to net more mileage.
 
I get 15 MPG lowest around town and 18 to 19 Highway at 65MPH with my 1990 2wd Suburban. Little tweaking to the ECM does wonders...

You'll never get this with tall, wide, heavy tires, this is the biggest killer of MPG available on an already heavy vehicle that has areo dynamics of a brick.
 
I can give you the best way to increse mpg in ANYTHING. Drive 55 or slower. It will make a big gain. You just have to weigh what is worth more to you, time or money.
 
And don't floor it so much. When the light goes green, give it 10% gas pedal. Sure, everyone around you zooms off, and people behind you are hating it, but who cares? At $4.00 a gallon or so, it pays to be frugal.

Besides, you almost always catch up with those folks at the next traffic light.
 
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