Better Gas Mileage? - Chevrolet Forum - Chevy Enthusiasts Forums

Better Gas Mileage?

Join Date: Oct 2010
Posts: 1

October 1st, 2010, 12:53 PM   #1  
CF Beginner
Better Gas Mileage?

i just recently bought an 01 silverado with the 5.7, i was wondering if any of you know what items i can buy to help improve the gas mileage and overall perfomance.....that is of course after the stupid emmissions test is completed....any advice would be helpful...thanks

Join Date: Dec 2009
Posts: 77

October 1st, 2010, 2:08 PM   #2  
CF Junior Member
Plenty of guys will come on here and tell you "buy this or buy that" but one thing you need to take into consideration is any time you begin to work towards performance you will begin to sacrifice fuel economy and vise versa. You can't have a performance engine that is good on gas it just doesn't work or a fuel efficient engine with much performance.

Join Date: Feb 2008
Posts: 121

October 1st, 2010, 7:24 PM   #3  
CF Active Member
i assume if you have a 01 with 5.7 then you have a 2500 or 3500.

then most likely you have a 4.10 ratio differential, if so that is going to kill fuel mileage.

just normal stuff: get a good tuneup with all ac delco parts, fuel filter, air filter, be sure you have std size tires, not 2 or 3 sizes bigger than std as that will just make it harder on engine.
take as much weight out of tool box an other non essential items out of truck,
drive 55-62 mph and no jack rabbit starts

try to find non ethanol gas, my 2500 with 5.7 seems to get better mileage with non ethanol fuel.

just remember you have a brick that weighs a lot going down the road, this vehicle was never know for good mileage, just a hook up and go to work old truck,

Join Date: Feb 2010
Posts: 406
Chesterfield County, VA

October 1st, 2010, 9:07 PM   #4  
CF Senior Member

Where do you find "non-ethanol" fuel? I know that here in VA, it seems as though every gas station has "10% Ethanol" stickers all over the pumps. We also have to use reformulated gasoline for most of the year.

Ethanol has a lower BTU count (less 'energy' per gallon) than gasoline, so you are going to get fewer miles per gallon with a mixture than with pure gasoline. Up in PA, they sell E85 (15 percent gasoline, 85 percent ethanol) from those corn-yellow pumps; and it costs about 50 cents a gallon less than unleaded regular. Unfortunately, your fuel mileage suffers quite a bit - which negates the reduced price at the pump. Doh!

It seems that not matter what we try to do, someone comes along and rains on the parade.

By the way, diesel fuel has very high BTUs and is not watered down with ethanol, but you obviously cannot run it in place of gasoline. The government has messed up the efficiency of diesel now, though, since the EPA mandates a 'DPF' (diesel particulate filter) on all 2008 and later diesel engines. It causes you to burn more fuel (lower miles per gallon) when it goes into "regenerate" mode in order to burn off the accumlated soot. {Hard to see how burning 15 percent more fuel is good for the environment!}

These newer engines also require the use of "ultra low sulfur diesel" (ULSD), pretty much sold at all pumps now -- and the lower sulfur content can sometimes be harmful to older diesel engines, for which the sulfur served as a lubricant. The older fuel - known as "low sulfur diesel" (LSD) is still sold sporadically, but can only be used in "off road" diesel engines; such as generators, marine applications, refrigerator units, heavy equipment, trains, etc., etc.

No wonder they charge so much for it!

Join Date: Jul 2010
Posts: 846
salmon arm BC

October 2nd, 2010, 10:26 AM   #5  
CF Pro Member
gear ratio change could help you, also changing the diferential fluids to sythetic can inprove milage, as well as a free flowing exhaust and intake, your call on how much you want to spend

Join Date: Mar 2010
Posts: 547
Redding, California

October 2nd, 2010, 3:26 PM   #6  
CF Senior Member
puting a turbo on the truck will get you better gas mileage plus more power whern you want it.
But as said, when you want power it will suck up gas. if you are easy on the throttle it atomizes
the air entering the engine when helps because when it mixes with the fuel there is not as much unburned fuel.
But if you have a lead foot and the turbine is constantly energized it will give you worse gas mileage.
Another thing you could do is add a highway gear so when going fast your rpm's are lower.
You could put throttle body spacers or a big bore kit in to get you more power.
You could also put in a cold air intake. good luck.

Join Date: Sep 2010
Posts: 12

October 2nd, 2010, 4:22 PM   #7  
CF Beginner
The best way to improve mileage on a pickup, borrow the wife or girlfriends car, that truck should get between 17 and 20 mpg. That is pretty good, my burb got 17mpg before the tires. And now about 11mpg but you have to pay to play, its all a matter of what you want. Engine upgrades are cool but if you don't really care about the power, spending a couple grand to just increase mileage, maybe 1 to 2 mpg, just don't make sence. Buy the

Last edited by Overtime; October 2nd, 2010 at 4:25 PM.
Join Date: Jun 2010
Posts: 290

October 3rd, 2010, 3:14 AM   #8  
CF Active Member
I agree with Overtime.

I have been looking into getting better fuel economy for my 08 Silverado (crew cab with 3.73 rear end). I get about 15 city and 18 highway (65-70) mph with tonneau cover (haven't noticed any change in fuel economy with the tonneau cover). I just went on a vacation into the mountains with my truck loaded down and averaged 16.8 mpg over the 2100 mile trip - 125 gallons of gas. Doing that math, $2.60 per gallon of gas X 125 = $325.00. If I spent just $300.00 on a cold air intake and got an estimated 2 mpg better, I would have used 13 less gallons of gas over that one trip. for a total savings of (13 X $2.60 = $33.80) So it took me approximately 2000 miles to save %10 of the purchase price of the CAI. So reason would have it that it will take 20K miles for that CAI to pay for itself. Now, if you spend more (exhaust, throttle body spacer, larger throttle body, different rear end gears, etc.) you could conceivably spend several thousands of dollars for a few miles per gallon savings. Just depends on how much you drive and the value YOU will get on the money you spent.

Now, I am guessing that a cold air intake can save that much gas. I don't have any real practical experience on CAI on a Silverado, so I don't even pretend I do. A lot of people on this forum swear by them. But, for me, I had A CAI on a previous ford truck, and really didn't like the louder sucking sound it made. The cost (price + louder intake sound) to benefit (negligible increase in MPGs + slight performance increase) wasn't worth the price to me.

It should be noted, that I drive my truck maybe 6-8k miles a year. So it would take quite a while for me to recoup my cost.

I do intend to get a KN filter though when my stock filter is worn out.

Hope this helps


Join Date: Jul 2010
Posts: 846
salmon arm BC

October 3rd, 2010, 10:46 AM   #9  
CF Pro Member
watch the k&n i installed one on my wifes car and it left a oily residue all over the intake on a 06 cobalt, im waiting for a sensor to fail on me, there are good reusable dry filters out there, that is what i am going to get soon for her car

Join Date: Dec 2009
Posts: 77

October 3rd, 2010, 12:13 PM   #10  
CF Junior Member
2wd-K5  watch the k&n i installed one on my wifes car and it left a oily residue all over the intake on a 06 cobalt, im waiting for a sensor to fail on me, there are good reusable dry filters out there, that is what i am going to get soon for her car
The main thing you need to watch out for is over oiling the filter. That's the thing that will cause eventual sensor failure.

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