? for 3/4 ton Suburban owners

I just bought a 93 Suburban 2500 4x4. I absolutely love the truck, but I'm only getting around 10 miles per gallon average! Dont get me wrong, I knew that mileage would suck when I bought it but I expected at least 12 or so. I have'nt even towed my boat with it yet. Does anyone have any idea what kind of mileage I will get with my Wakesetter on the back?

Greg, try this site:

http://forums.vmag.com/suvsuburban0103/

I have a 95 3/4 with 7.4L engine and 3.73 gears. I get about 10 to 12mpg around town and 14 on the highway. Towing I get around 10mpg.

I replaced some the stock igntion gear with MSD, put a KnN filter and chipped it. All helped a little bit, maybe 1mpg. I just have not got around to a new exhaust (new muffler and cat).

Sean, I'll check out the site later. Thanks.
It sounds like you're getting good mileage on the highway. I just put in a K&N. I have no idea what gear I have. I do have the 5.7L though. What is MSD?
Greg

Greg, check out http://www.msdignition.com/

They make performance ignition components for cars, trucks, boats...

Also check out http://subtopics.freeyellow.com/subtopics.htm

Watch out though, lots of pop ups on that site. I turn on my Pop Up Stopper before going to that site.

There are only a couple of things that will increase milage and with a big block 10 around town and towing with 14 open highway is normal. Small blocks get a little better, on the open highway not towing (sorry not sure what), but get about 10 towing. It is really funny how the small blocks and big blocks tend to get about the same fuel milage.

I do not buy the hype of the aftermarket ignition systems. The factory one will kick out over 45,000 volts, and timing is controlled by the computer anyway so an aftermarket coil is not going to do any good. Changing out the cat and muffler will open it up and give you more free flowing power. I went with a Thrush high flow cat and a rather large Magnaflow muffler which is way quiter than a Flowmaster and much better quality. I used the factory exhaust pipes and just removed the factory muffler and cat and replaced just that section, even using the factory exhaust tip.

How does it idle? Was it tuned recently? Always make sure to use factory GM parts, nothing hot rodded or cheap like champion or autolite. They have a few quirks to them like the distributor magnets/pickups go bad and will cause timing fluctuations. I would just replace the oxygen sensor with a new GM unit.

We have a 1998 3/4 ton suburban and I'm towing with better than 12. It is 2 wheel drive, not 4 and it is all stock. Actually it gets better mileage around town than my jeep.

The real cost I wasn't expecting is that it eats brake shoes. Plan to redo your brakes with every third oil change or so. Too much weight to stop in a hurry in Southern California traffic.

Pete, I respectfully disagree with your statement that a small block should get better mileage. I think that on the full size suburban the weight is taxing on the small block and will actually give worse mileage than the big boy.
I have also seen some other posts that agree with that.
In other cases, such as the 1/2 ton, its as you say.
My '72 has had both. The 350 definately gives me
better mileage. Thats whats in there now.

One thing on the older 3/4 ton trucks is that they do tear through front brakes at the rate of about every 20-25K mi. Adjusting the rears at every oil change is neccessary to lengthen the life of the fronts and give better stopping power.

Sandy, if you reread my last line I said "funny how the small blocks and big blocks tend to get about the same fuel milage". I have not owned a small block powered tow vehicle ever, but I still can not imagine them not getting somewhat better milage when cruising down the freeway unloaded. I would say we are pretty close to being on the same page.

Thanks for all the advise. I think I'll try to replace the oxygen sensor and see how that works.
I just noticed that the front brakes need changed the other day. It idles fine, but come to think of it I have'nt tuned it up yet,and when I buy a used car that is usually the first thing I do.

Greg

Well, Pete you are 100% right.
And, for the record I usually agree
with you. We're usually on the same page
: )