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2500 Fuel Economy



Quick question for anyone with the 3/4 ton AV. What kind of mpg do you get? While I'm at it do you think it is worth the extra $$$$ to go up to the 3/4?

I guess I'm getting a little indecision at the last minute on which one to go with.
I have heard the ride is a bit harsher due to the leaf spring suspension and other beefier parts underneath.

If you do not need the towing or weight carrying capacity why buy it?? ???
I meant harsher than the 1500 Z66 or Z71...no harm intended. ;D
I've only been able to get an approximate MPG once and it was 10 mpg during break-in. I have a hard time getting the tank to fill (I'll post this to the appropriate forum). Official estimated MPG is 13 or so.
As for the ride, I didn't notice a big difference between the two. I have no complaints with my 2500. And, no, I don't have a "bigger is better" syndrome. ;) We just have a large trailer to haul.
Ride of the 2500 is sweet - not a problem - if you crank the torsion bars up a little to fit larger tires, it gets a little stiffer, it is a truck when all is said and done.
I've put in two tanks on my new 2500. It's a 4x4 with 4.10 gears. First tank 10.6, second tank 10.8. As to ride, my wife thinks it is worlds better than the 94 Suburban, 2wd, 2500 that traded in on the Av.
I've had my 2500 w/4.10 rear end for a bit over a week. The first fillup provided ~10.2 mpg, the second gave ~10.6 mpg. Bear in mind that we jsut got dumped on with a foot of snow the first week I had it, then we got dumped on with another foot of snow over this past weekend, so I've been in 4x4 mode quite a bit.

I opted for the 2500 to do plowing. I realize that there are a lto of people plowing with 1500's and 150's ( :p ), but I figured why not get the beefier suspension and frame, it should pay for itself in the long run. Plus that 8.1L cruises like a dream.

Later in the summer I plan on sticking in an input filter kit (K&N or AirAid) which is supposed to help with the mileage. You can ask gandalphxxx if you need more info on the input filter kits.

I'll continue to post updates on mileage on the 2500 as more info comes in. It seems like there are quite a few people here interested in this (like me). It's been quite a shock going from my Pontiac GP GTP that was getting ~25 around town and >30 highway.
ratthedd said:
I opted for the 2500 to do plowing. ?I realize that there are a lto of people plowing with 1500's and 150's ( ?:p ), but I figured why not get the beefier suspension and frame, it should pay for itself in the long run. ?Plus that 8.1L cruises like a dream.

Did you get the snowplow prep package? Did you have to factory order or did you find it on a lot? What does the prep package give you? Where is the Aux Light switch located?
This what it contains - wires are coiled up in headliner above driver pillar. It was originally supposed to have heavier torsion bars for the plow load - don't know what happened to them.

VYU SNOW PLOW PREP PKG (inc: 10 amp backup pwr,
high- flow front bumper, forward lamp wiring harness,
42mm access hole in dash panel, 130 amp alternator
(w/ MT1 or M74 Trans- inc: trans oil cooler)

Check the complete thread @ GM-Trucks.com

I went with the 2500. I have 1500 miles on mine now and have seen 12.4 @ 70 mph as best so far.

I added K&N air filter and flowmaster. :)

2500 4X4 8100 :)
I hate to say this, but, 2500 and fuel economy is an oxymoron - IMHO, you get one because you need it for towing, hauling, or you just plain want it. ;D
Chief Avalanche Fan said:
Where is the Aux Light switch located?

To the right of the ashtray. IN mine it appears as if there is room for two switches there, the one installed says 'Aux Lights' and the other space is blank.
gandolphxx said:
I hate to say this, but, 2500 and fuel economy is an oxymoron - IMHO, you get one because you need it for towing, hauling, or you just plain want it. ;D

True, but that won't keep me from trying to get get as much as I can from a tank. If all I wanted was great gas mileage I would have kept my 500cc Yamaha--I feel much safer in the 2500.
Chief Avalanche Fan said:
Did you get the snowplow prep package? ?Did you have to factory order or did you find it on a lot? ?

I forgot to answer these questions earlier...

Yes, I've got the snowplow prep package. It wasn't on the lot where I went, but they found one 23 miles away and picked it up for me. I didn't originally want the luxury package (onstat et. al.) but I'm not complaining.

Now I've got to save up for the plow. Blizzard has some relaly noce ones, but they retail for about $5k. I'll check out the want ads over the summer. There should be some decent deals going on with used and old stock.
I have a 2500 with a 4.10 rear end. The last two tanks of highway driving have been 15.7 mpg and 15.2 mpg. City driving usually yeilds about 11-12 mpg.

Actually, this is about the mileage I was getting from a 1998 Suburban 1500 (5.7 engine) with a 3.73 rear end.

Totally love the 2500 Avalanche. The ride and power is far superior to the 98 Suburban. Actually, the ride is better than the 2002 Suburban.
Our (actually it is my wifes :eek:) 2500 has gone through one tank and is on its second... We did not do a great job monitoring the first tank so we estimated around 11miles per galon in all city driving and in 2wd. This tank is on its way to getting closer to 13 under the same conditions. At our first oil change (done today) we found nothing out of the ordinary except for having to put in all of 7 quarts of oil in the cranckcase... We also noticed loud ratling (much like valve clattering) when the vehicle was just started (but it went away within a few seconds... can you say relief...). Can't wait for the 3k mile marker-- it will get some Mobil 1!

As for the ride... well it was interesting to find out that the recommended tire pressure in the 2500 is of 80psi rear and 40psi front... I figured that would be fine when under a heavy load so I went ahead and put 50 in the rear and 40 up front... Took back home and found the ride had improved. Very impressive considering the weight and the truck's purpose.

OK, I've been keeping some of you up to date on the fuel usage of my 2500 w/4.10. The first tank netted 10.2, the second netted 10.6, and the third was just a hair under 10 mpg. Keep in mind this was mixed city/highway, and due to breakin period I was not using the cruise (read gas on/gas off). Also that third tank was mostly in 4WD due to a big blizzard.

Friday I changed the oil (1100 miles) and did about 100 miles of freeway driving. I set the cruise at 75 and off I went. I also did a little punch and go at the lights in South Bend, and passed a guy doing 50 in a 55. It's always nice to look at the meter after pulling back into your own lane and realizing that you're going over 80. ;D

Anyway, this morning I filled up again and calculate the mileage at 11.69. This is still stock. Once the weather gets warmer I plan on installing the PowerAid / AirAid duo. I'll let you all know what changes those make.
The ongoing saga of the 2500 fuel mileage...

This morning I filled up again (holy moly has it only been 4 days... :eek: :eek: :eek: ) and calculate the mileage at 12.33 mpg.

This is in mixed city/highway driving without trying too hard to be fuel conscious, meaning that I still like to stomp my foot at the light changes.

Stay tuned for more.
I just got 14.5 mpg in my 2500 I have 2100 miles on it now. I set cruise at 75. I also have flowmaster exhaust and K&N air filter. I use Valvoline full synthetic oil.

Summit White 2500 4X4
Please post your 2500 AV's gas mileage in the city and highway.. I'd like to see the "real life" results..

Drove an 8.1 the other day...man, that thing has some major get up and go... just wondering how much it affects fuel economy ?
Dude, if you have to ask about gas mileage for a vehicle that weighs 7000 pounds and has a 496 cubic inch engine you're probably not cut out for ownership. No offense but 1500 Avs aren't exactly gas misers and the 8.1L big block drinks gas very well. And if you have a 2500 Av like mine with 4.10 gears, 4-wheel drive and 35" tires (6" RCD lift) then you're a candidate for frequent gas station donations. ;D
Even with a supercharger I can do in the 12-13 range on long trips if I use cruise control an stay about 72 MPH - in the city it is not that good and I don't even measure it at the track >:D