GM Truck Club
Founded in 2004 ~ We're the #1 Chevy Truck & SUV Forum.
Silverado & Sierra | Tahoe & Yukon | Suburban & Yukon XL | SUV & CROSSOVER
Results 1 to 10 of 10

Hybrid View

  1. #1

    Default help for new silverado owner

    hey guys, i just purchased a 2002 1500HD, i heard that you can improve power and fuel economy by helping the the 6.0L breathe better. i was just wondering which CAI and exhaust combo you guys have used in the past, and what kind of fuel and power numbers to expect. I would like to go with a true dual exhaust if i could because i love the "blattty" sound (blame it on being a MN farm kid)
    2002 Silverado K1500HD (NEW!!!!!!!)
    1999 S-10 Blazer
    1990 K1500 5-spd TBI 350.
    2001 Monte Carlo SS Pace Car

  2. #2

    Enkeiavalanche's Avatar
    Join Date
    Apr 2010
    Piermont,NY, back in Northern NJ now, But may be in IL soon....


    Well some have and some have NOT.. It all depends on your Right foot.. A Cai and Exhust are nice for a bit more power and a Programer can help with that too.. As for better MPG's with a 6.0 What are you looking to get? You are now getting on Avg between 12-14 MPG If you take it easy and coast more you MAY see 14-16 MPG on Avg...
    08 Z71 Avalanche Mods to date: K&N CAI,Hellwig Swaybars and End Links, Corsa Sport Exhaust, Superchips Programer,IPCW LOF & 3rd brake light and tails, AMI Gas door,Show Hooks and Door locks, Enkei Wheels, with Pirelli tires, StreetScene Bowties, Grant Steering wheel,Muth signal mirrors,SSBC Big Brake kit,Huskyliner Mug gards,Floor mats and Hood shield, McGard Lug nuts and locks, Bedrug, Cervini's Ram Air hood,35watt HID Fog lights, Sylvania bulbs all around ZXE's Highs and Lows, WhiteNight Back up lights,Sirius and HD Radio, SnugTop sitting on deck now Got a Softopper on now,Tempress Boat Hatches.... New Bilstein shocks are on... New Mods coming soon..... X

  3. #3

    Join Date
    Sep 2010
    everett, massachusetts


    your vehicle as built is designed for the best MPG. as for power increasing small amounts can be achieved with some program changes to the PCM. now if you wish to create more noise and lower MPG changing the exhaust and the PCM programing will create this effect but at a MPG loss. since your a new owner of this vehicle I would first replace all drive train fluids and replace the dexcool with GM approved dexcool and distilled water to the MAX 65% . this will reduce corrosion which is common with these engines because of insufficient coolant concentrations with non distilled water . this is part time 4wd so never use this 4wd in any 4wd selection on dry solid pavement.rotate tires every 15,ooomi and keep the tires all evenly worn of the same wear so the the driverain does not get damaged. your vehicle transmission fluid spec has changed the fluid now approved by GM is DEXRON VI, so do not use any DEXRON III........

  4. #4


    I'm pretty sure one of the more senior guys will tell ya the same thing, but exhausts are almost a personal choice. I myself prefer the Magnaflow system, and had it installed on both my Silverado and my current Sierra. Almost the same story with CAI's. The most noticeable change will be the sound the engine makes while drivin. Some guys will say that a K&N filter with the stock intake box will be fine, however I noticed some differences between my aftermarket system and my stock box. I bought a Volant CAI kit, and it has two more openings to receive air, removes the stock system's air baffles, and was able to use the stock MAF. The included filter for the kit needs to be oiled, so I'd recommend upgrading to Power Core filter which is good for 100,000miles if you go that route.
    Between the two systems (and a custom tune), I have noticed a slight uptick in my MPG ( it's more stable through a varied driving conditions). I am able to maintain high 15's to 16's combined between city and highway, with an impressive boost to acceleration.
    A combination of intake and exhaust WILL help your engine breath better and give a SLIGHT performance boost (depending on system, might not be noticeable). I will say that I have yet to run across somebody who upgraded these systems and thought the stock set up was better! There are plenty of options out there, and this group can give ya feed back on pretty much all of em to help you with your decision. I say go for the upgrades! Good luck and let us know what you finally decide to do! Feel free to pick everybody's brains if you have questions about specific systems!

    2010 GMC Sierra 1500 SLE Extended Cab Z71 4X4 5.3L Flex Fuel
    MagnaFlow single in duel out system
    Volant CAI & Ram Air Scoop with Power Core Filter
    Rhino Tuff Grip Spray in Bed liner
    Undercover Classic Tonneau
    Trail FX Bug "deflector"
    AVS Window Deflectors
    Black Powder Coated Nerf Bars
    RECON L.E.D. Interior, 3rd Cab light, Projector headlights, and Taillights
    ATX Crawl Wheels wrapped in BFGoodrich Rugged Terrain tires
    CalTrend Neoprene seat covers
    2" leveling kit from Max Trac
    Diablo Trinity with Diablew Tune

  5. #5


    Thanks for all the input so far guys, my ULTIMATE goal for fuel economy is between 20-22 MPG hwy, but please understand I know this is going to require ALOT OF UPGRADES, to include driving style as well. For right now, I am looking to get 12. I have only had this truck a week now. On the second fill, i pumped 17 gallons with 185 miles on the trip odometer. That comes out 10.5 MPG. My buddy has an '02 2500HD with the 6.0L and says I need to keep all shifts below 2,000 RPM's, so I have been doing that. Right now, I have 121 miles on the trip and am at half tank.

    To achieve this 20-22 Hwy MPG, my plans are going to include cam, valve train and head changes. Intake and exhaust port matching and well as a complete exhaust redo. Afterwards I will be looking at dyno tuning. But the full completion isn't schedule for at least another 3 years minimum.

    Another problem that I noticed that may (and probably is) messing with my fuel economy is the fact that I have 285/75/16 LT tires, whereas OEM is 245/75/16 LT. I also have ranch hands front and rear, which I know is heavier than stock.

    I am very open to driving advice that my fellow 6.0L owners have noticed is increasing their economy.

    Thanks to those of you who have already replied and to those who are going to do so. I will upload pictures of my new rig directly. It will be in my garage.

  6. #6


    A CAI is not going to do much, the air filter housing is already acting as a CAI. Getting rid of the restrictive resonating tube and going with an MIT will give you slightly better throttle response.

    Replacing the water heater sized muffler will help a little bit as well. A catback dual exhaust is a good idea.

    Using a programmer like a Diablo/Hypertech/etc. will give you some better HP.

    Remember, the truck was designed to get the best power/mileage with being as quiet as possible. If you are willing to tolerate a little more noise, you can do better in the power area.

    With doing all three, you can probably pick up an extra 30HP using a premium tune, about 20HP with a regular gas tune.

    2013 Silverado LTZ White Diamond Crew Cab

    Advent OGM1 Navigation
    Husky Liners GearBox Underseat Storage
    Airaid MIT
    EGR Rail Caps
    K&N Air Filter
    Flowsound 40 Muffler
    Hypertech Max Energy Tune (only top end limiter removed and AFM disabled)
    Chrome Tailgate Handle Cover
    TonnoPro HF-155 Tonneau Cover
    WeatherTech Front and Rear Splash Guards
    Husky Liners X-Act Contour Floor Liners
    WeatherTech Side Window Deflectors

  7. #7

    Join Date
    Sep 2010
    everett, massachusetts


    you will never get 20-22 MPG with this vehicle. lets say you do get 20 MPG with this vehicle with the use of 87 octane fuel then this would be the only one in the world to have this occur.

    the most this vehicle can get with driving very easy and no loading is 16MPG. so you would have to increase the MPG 4 more than anyone I have ever talked to got with the work they did.

    with the engine work you do if you do get the 20-22mpg then you should try to sell the system improvements you fabricated.

  8. #8
    Jr. Mechanic
    Join Date
    Mar 2013


    sounds like youre mpg is on the low side.check cat back pressure,disconnect vacuum line on intake,ofcourse after warm up,see if youre close to 22 inches on reading,20 is o.k.and hopefully steady on idle.
    Cats are finicky on these vehicles.Ive seen some clog up with 1 02 sensor flucky,others not a problem.
    please respond,we all learn from here

Similar Threads

  1. Replies: 0
    Last Post: 07-17-2012, 01:27 PM
  2. Replies: 0
    Last Post: 05-09-2012, 01:00 PM
  3. First time Silverado owner, not GM truck owner
    By RSSebura in forum Member Introductions
    Replies: 18
    Last Post: 04-11-2012, 01:43 PM
  4. Replies: 0
    Last Post: 01-31-2012, 03:50 PM
  5. Replies: 0
    Last Post: 01-27-2012, 11:50 AM

Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts