Can I Get 20mpg?

4winds · May 11, 2009

I've got a 2004 Silverado 1500 Z71 (4x4) with a 5.3L Auto ext cab. I currently get 16.5mpg with 60/40 highway/city driving. I'm looking at selling my motorcycle for safety's sake and wanting to boost my mpg a bit as I drive quite a bit each week. I'm thinking about adding a volant CAI, magnaflow single exit exhaust system, and possibly a tuner with an economy setting. If anyone has any advice, success stories, or thinks it can be done, I'd love to hear it. Thanks!

jrrod2004 · May 11, 2009

I've got a 2004 Silverado 1500 Z71 (4x4) with a 5.3L Auto ext cab. I currently get 16.5mpg with 60/40 highway/city driving. I'm looking at selling my motorcycle for safety's sake and wanting to boost my mpg a bit as I drive quite a bit each week. I'm thinking about adding a volant CAI, magnaflow single exit exhaust system, and possibly a tuner with an economy setting. If anyone has any advice, success stories, or thinks it can be done, I'd love to hear it. Thanks!

yeah, change your gears to 3.23 or lower

Jenna's forcefed princess comes to mind when it comes to fullsize economy and power....

georgecdisc · May 11, 2009

I've got a 2004 Silverado 1500 Z71 (4x4) with a 5.3L Auto ext cab. I currently get 16.5mpg with 60/40 highway/city driving. I'm looking at selling my motorcycle for safety's sake and wanting to boost my mpg a bit as I drive quite a bit each week. I'm thinking about adding a volant CAI, magnaflow single exit exhaust system, and possibly a tuner with an economy setting. If anyone has any advice, success stories, or thinks it can be done, I'd love to hear it. Thanks!

CAI and Exhaust usually do little towards performance increases. Typically they are more for sound (don't get me wrong they do help some, but not enough to cause +4 mpg). A tune is where you will probably see a benefit. If I ever get an opportunity I will get a 93 octane tune on my truck, which should help with mileage (pay a little more for gas but mileage-wise I come out on top). Others might have some success stories, but as far as I know there is little that can be done. Simple things such as checking tire pressure, changing oil, etc are pretty big factors. Also how you drive can make a vast difference.

bubba33 · May 11, 2009

I f you figure out how much your going to spend to get better fuel milage,it may take awhile to just break even.Lets say you get 16 and if you do the mods your talking about ,you get it up to 19. If you drove 15000 miles a year ,you would save save around 300 bucks. Thats figuring gas at 2.00 a gallon. How much will it cost you to do the mods. If you just want the mods for milage I don't see that paying off.

tobias · May 11, 2009

Either buy a car or live with it, that's my advice.

A tune will help more than anything but remember, you are driving a giant brick and nothing is going to change that.

4winds · May 11, 2009

I f you figure out how much your going to spend to get better fuel milage,it may take awhile to just break even.Lets say you get 16 and if you do the mods your talking about ,you get it up to 19. If you drove 15000 miles a year ,you would save save around 300 bucks. Thats figuring gas at 2.00 a gallon. How much will it cost you to do the mods. If you just want the mods for milage I don't see that paying off.

I drive about 20000 a year. I'm not concerned about mpg's at all when gas is at $2. It is when it rises to $3-$4+ that I get concerned, and it there where I would come out ahead... at least according to my hypothetical mathematics. Thanks though

Nick The Great · May 11, 2009

I don't think it's realistically possible.

My 99 RCSB, 2WD truck could do that. But that was with the 4.3L V6 and ideal driving conditions: no wind, 55mph on the highway, etc.

But you have an Extended Cab, 4x4, Z71 truck. That's a lot of weight. The 5.3L V8 isn't the smallest engine out there either. It's a good engine, but thats not the point.

You could maybe squeak a few more mpg by changing gears, adding a CAI intake, tonneau cover, and putting an egg under your foot. I just don't want you to get your hopes up.

Good luck

Patrick11 · May 11, 2009

I average 18.5 to 19.5 in my 05 5.3 crew BUT I have all country roads around here with hardly any traffic, I havent done anything for performance mods as of yet but its soon to change, just dual exhaust for the noise, I have a tonneau cover and a fairly light foot usually run around 55 to 60.... I made a trip to Oswego New York fishing last year and we had 5 grown men in my truck plus all our luggage, and we averaged 80-85 most of the way and believe it or not my pick up got 19.2 avg mpg BUT we was following my bosses pick up

EDIT:Winter time its a little different story, I only average about 14mpg then.... maybe its just me and dont know if anyone else has noticed but it seems to me that I have lost a little gas mileage since they started adding ethonal to the gas, and I didnt know if im just imagining things or if anyone else has thought that too, but I didnt get a truck for great gas mileage anyways

Green_Monster · May 11, 2009

Buy some very lightweight, low roll resistance tires. A skinny highway tire. The link is just a few examples. Compare to tires like the BF Goodrich A/T. Which is a very heavy tire. I think around 45+ lbs.

Tire Rack

My mpg dropped from 19 on the highway at 70 mph to 17.8 when I switched from the original tires to my Firestone Destination A/T tires. They weight about 8 pounds more per tire if I remember correctly.

BF Goodrich comparo

bubba33 · May 11, 2009

I f you figure out how much your going to spend to get better fuel mileage,it may take awhile to just break even.Lets say you get 16 and if you do the mods your talking about ,you get it up to 19. If you drove 15000 miles a year ,you would save save around 300 bucks. Thats figuring gas at 2.00 a gallon. How much will it cost you to do the mods. If you just want the mods for mileage I don't see that paying off.

I drive about 20000 a year. I'm not concerned about mpg's at all when gas is at $2. It is when it rises to $3-$4+ that I get concerned, and it there where I would come out ahead... at least according to my hypothetical mathematics. Thanks though

I am sorry was just trying to help. I didn't see the part in your post where you were not concerned about fuel mileage right now. Your just worried about later on when or if fuel is at 3 to 4 bucks a gallon. I don't think you will get 4 mpg better anyway.

05silvycrew · May 11, 2009

I think 20+ is completely possible with the right set-up. gears and speed are the main factors.

my truck: 05 crew, 5.3 iron block, 4.10 gears.

I can make 17.5-19 MPG on the highway at 60 MPH

I can make 16.5-17.5 MPG on the freeway at 70 MPH

swap the iron block for aluminum, take my 4.10s and replace with 3.73 gears, and I'm confindent I could make 20+ on the highway. replace with 3.42 gears and I think 20 is even possible on the freeway.

you can do some breathing mods on the cheap too, then your turn around time decreases:

get an airaid tube and free-flow filter instead of a whole intake. $150 vs $250-300

get a free-flow muffler instead of a whole catback exhaust. $100 vs $400-800

Chris · May 12, 2009

my 04 4.8 ecsb will average about 18 with cai and exhaust. and my bed is aull 100% of the time with usless crap that wont fit in my dorm room. its possible to do. i just drive fast and downshift to slow down. and city/hwy is about 80/20

Booy501 · May 12, 2009

I have an 09 5.3 4x4 with the six speed and with 80/20 hwy/city I easily get 19.5 mpg. That's with a light foot and no more than 65 mph on the hwy.

2005LT · May 12, 2009

With my old 05' Silverado 1500 ext. cab 4x4 with 5.3L (aluminum) and 3.42 gears I could get 20 mpg quite regularly on the highway (strictly). I could get this if it was somewhat calm outside, keeping it to 70 mph or less on fairly level ground. I had stock 265 tires on it as well. In the city it would get about 15 mpg.

NFSGamerUSA · May 12, 2009

The best way to increase economy is not with performance mods, but with higher gearing. Look at the new XFE models GM sells. They come equipped with 3.08s, although 3.23s might be a better choice for you since yours has the 4L60-E and less power. Don't count on beating anyone at the stoplight drags, nor towing a whole lot of weight easily. The next best thing you could do would be to put on 245/75-16 tires. I think 245/75-16 Bridgestone Dueler H/T D684 II tires in 109S SL form are the lowest rolling resistcnce tires available for you (well, according to Wikipedia ). Those, BFGoodrich Rugged Trail T/A, or Michelin LTX M/S tires would be best, but size (and weight) is the more important role. Smaller tires will also help you regain some lost power, as well. Then there's switching the synthetic oils, but you're pushing it, then.