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To buy a 2500 or upgrade my 1500?

Lycan

New Member
Joined
Nov 11, 2019
Messages
5
Hi all, newish avalanche owner (had it for 5 months now) sorry if this has been posted in the wrong place. Basically I want to get the most out of my 04 avalanche because I plan on keeping it a very long time or at least until a good deal for a newer one comes my way. I own a 1500 base model, and so far is everything that I want out of a truck with my lifestyle, but I plan on getting a camper and a boat for some fishing trips and just overall just time to get away and relax. I also plan on occasionally taking it off roading when I can just for the heck of it. The questions I have are as follows:

-Would it be easier to buy an 4:10 axle, transmission cooler,  and leaf springs/aftermarket suspension or to keep hunting for a 2500 in my area?

-Has anyone installed or considered throwing in a 6 speed transmission?

-Any options for a larger gas tank?

-Any roof racks that don't require drilling for a naked roof?

-Recommendations for auxillary battery setups? And any recommendations on quality of life mods?

-Any recommendations for improving fuel economy?

I have tons more that I'm sure are probably already answered on a thread somewhere but I'm still learning to navigate the forum
 
First  :welcome:.

You mention looking in your area.  What is your area?  You also mention trying to improve fuel economy.  Moving up to a 2500 will take fuel economy in the opposite direction as will adding 4.10 gears. 
 
My area is northwestern Ohio, and yes I'm aware going to a 2500 or swapping the axle will take away from it, but in the event that I find a boat or trailer that's light enough I was curious about anything you guys have done that will slightly improve it. I was told by a buddy to just swap the engine for a 5.3 vortec with the AFM and that'll help since it's only running 4 cylinders until the others are needed, but research says that the lifters are weaker  in engines with active fuel management so that kinda pushes me off from that
 
Short of a custom programming and keeping it well tuned, I don't think there's a whole lot that can be done to improve mileage.  They're big thirsty vehicles.  What kind of mileage are yo getting?  That may help deduce if you're right there with the rest of us or if something is amiss causing lower than average. 

In the buyer's section, there is a one owner 2500 for sale near Toronto.  Looks pretty nice and I have an internal battle brewing in my head.  You're closer to it than me (Cincinnati).  Being in Northern, OH you may want to consider actually looking south vs. in your area since you'll have more rust issues than us - and ours are pretty major. 

There are threads here addressing dual battery setups, transmission coolers and engine swaps.  I don't recall if I've seen anybody do a six speed swap but I wouldn't be surprised if there's a thread on that too. 

Good luck in your quest.
 
First welcome to the site!

You are right in that most of your questions are answered in separate threads that have been posted in the past. Look in the appropriate mod section for ideas about each issue or get familiar with the word search functions to help sort things out for you.
As others have mentioned an AV is a very heavy vehicle and has the aerodynamics of a brick so it is a poor starting point for a gas economy vehicle. The best things to do is to keep the AV as stock as possible with good maintenance, tire inflation etc. and drive it like an old geezer (no jackrabbit starts or rapid stops)  with limited stop and go driving, also avoid very high speeds like over 70mph.
It would help us answer your questions if we had an idea what size and weight of trailer or boat you plan to own since it can be decided by towing capacity of a 1500 v. a 2500 also what percentage of the time will you actually tow? The 2500 will use more gas on a daily drier condition but is probably less affected during towing then a 1500 under max towing conditions.  Also how long to you plan to keep an AV, just a couple of years or long term?
Most of your mods could be done if you have the time, tools and money to spend buy would it be a financially smart thing to do? Only you can answer that based on things like if you spend XYZ amount of money to mod the AV how many miles would you have to drive or how many years would you have to own to have it pay for itself?
AS far as a quality of life improvement one of my families favorite mod is a bedslide type device that makes it easy to load or unload the bed without having to lean over the tailgate or climb into the bed  here are a couple of companies and for the AV you just bolt to lower cargo tie-downs (no drilling needed):
https://www.bedslide.com/
http://www.cargoglide.com/
 
Not sure if the boat or trailer weight as I'm still shopping for one that works best for me but I can always go lighter. When I get said boat and trailer, it'll be fairly often because when the weather's warm I go fishing almost every day after work and on weekends, and considering camping around while I travel to warmer areas in the winter months. I do plan on keeping it long term as I don't need anything new and shiny, just something that suits my needs. As for the other commenter asking about my current milage I seem to be averaging about 10-13 mpg overall, I know my evap canister needs to be replaced but I haven't gotten to it yet and I don't think it would kill my milage that much. I may be wrong though, I'm no pro mechanic just a guy who's good with his hands
 
Oh wow, that does seem low for a 1500.  Seems most people get between 13 - 16.  I normally get in the upper 13s to upper 14s with mixed city/highway driving.  Do you have a code reader or USB reader to check things such as fuel trims, etc?  A few things I would consider and/or look for:

  • When was the last tune up (plugs, wires, etc.)?  It could be time
  • Check for any vacuum leaks
  • Clean the MAF
  • Clean the intake
  • New fuel filter and fuel injector cleaner
  • Could be time for new O2 sensors
  • Could possibly be clogged Cats

There are others far more knowledgeable than me on the forum.  They may have some insights for you as well.
 
I only skimmed this thread so sorry if I missed something but 10-13 sounds awfully low. I would swap the plugs for new laser iridiums but it also might be your tires? I've opted to not go for bigger sexier tires for just that reason. I can get away with it though as I'm in south florida, might be more important up where you are.
 
I don't have a code reader myself yet, but I took it and had the guys at 2 different AutoZones run it through their scanners just to make sure I was getting the right answer. I got a P0446 which Google tells me is my canister purge valve/vent but I'm waiting on the weather to warm up a little so I can get in there and swap it out. As for tires, Ive been shopping for some new ones anyways (all season would be helpful in this snow) any recommendations?
 
Lycan said:
I got a P0446 which Google tells me is my canister purge valve/vent but I'm waiting on the weather to warm up a little so I can get in there and swap it out.
While the weather is still cold, watch this video on the P0446 code
https://www.youtube.com/watch?v=Xc4UJIU0M70
 
Lycan said:
I don't have a code reader myself yet, but I took it and had the guys at 2 different AutoZones run it through their scanners just to make sure I was getting the right answer. I got a P0446 which Google tells me is my canister purge valve/vent but I'm waiting on the weather to warm up a little so I can get in there and swap it out. As for tires, Ive been shopping for some new ones anyways (all season would be helpful in this snow) any recommendations?

I have Michelin Energy Saver's on mine. They're boring and might not be great for the snow but they definitely don't bog your mpg down. Also if you're looking at OBDs check this guy out

https://www.rockauto.com/en/tools/electrical,tool,obd+scan+tool,1001199

Stupid cheap, but I went through 3 different higher end models and there isn't any noticeable difference as far as diagnostics go. I returned all the other models and stuck with this guy. Only want the high end stuff if you need more live reporting.
 
I have a 2005 2500 model Avalanche (Sunburst Orange II), love this truck and won't even consider selling it or trading it off.  In fact, I just bought another Avalanche, a 2009 1500 model.  Nicer options, and better gas mileage but my 3/4 ton Avalanche is softer to drive in my opinion. So now I have two and my wife is annoyed.  I'm thinking of getting a black diamond next!

Enjoy!!
 
Lycan,
If you can find a 2500 that is in decent condition, don't even hesitate.
Got my 2500 in early 2016 if I recall right. It's a joy to drive...but eats gas  >:D
But worth it 'cuz it tows so nice compared to any 1/2 ton.

CarMech1969
 
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