Ok I have a 2003 GV with the V6 and a auto tranny. It has been getting 18mpg since we bought it and frankly I am concerned why this thing wont get better gas mileage. Hell my Chevy Tahoe gets better mpg. The GV has stock wheels and tires, 16" with 235/60-16 tires. I wonder if going to a 15" wheel and 235's would help it any.? At 70mph it is almost hitting 3k on the tach. Does anyone else have a GV that gets better mpg? If you do please let me know what changes you have done...Thanks Colby

I have a manual and get 24.5 Imperial - I would expect no better than 22 with an auto - that's 18 US, so you are pretty typical, I think.

I've looked up the Tahoe manufacturer's figures, and they are impressive for the engine size and weight, but does anyone actually get them?

I get 23 MPG routinely, in mostly back roads & HWY driving, 45-65 MPH w/a manual trans.

3K is exactly 70 MPH on mine. It's geared too low to be a fuel sipper, but you gain some power at the lower speeds as it is designed.

A slightly taller tire should show some improvement in MPG, as long as you keep your foot out of it, and are not trying to compensate for the slight power advantage that you have now.

Ever try any fuel injector cleaner? RedLine and Seafoam are good ones. 

I wonder if going to a 15" wheel and 235's would help it any.?

It's going to be hard to get a 15" on there without it fouling the calipers - also you haven't specified a tire profile, which makes the discussion meaningless - if you could go to 15s and used a 235/60R15, it would be an inch smaller and I'm pretty certain you'd see the consumption increase.

Don't think you will fit 15" rims on your truck because of the caliper clearance issues.  Have you considered going to an 85 series tires (narrower and taller)?  215-85-16s series tires are about a 30 inch (+/-) tire that are about 6-6.2 inches wide versus a 7"(+) width for a 235 series tire.  235/85/16s should put you in the 31" inch range.  Several companies offer a good A/T tire in this size range.  

More diameter with less rolling resistance, should get you more MPGs with all else being equal.  Keep in mind once you over size your tires, your odometer will continue to provide feed back on based on the stock wheel diameter because it doesn't re-calibrate for the new ratio you have created.  You have to factor this info into your MPG computations.   BLUF:  with taller tires you are covering more distance with each revolution of the wheel = possibility of obtaining more miles per gallon IF the rolling resistance is reduced.  

That mileage sounds about right.  Maybe 1 or 2 low but not much.  I had a '03 GV setup like yours and the best we ever saw was 19mpg around town.  You have to rev those little V6's to haul the 3,000lbs or so around and gas mileage suffers because of it.  Freeway we saw 22-23 ONCE on the way to Florida from Michigan.

15" wheels won't clear the brakes on the Suzukis.  Trackers have different, smaller brakes, so they do clear.

Don't think you will fit 15" rims on your truck because of the caliper clearance issues.  Have you considered going to an 85 series tires (narrower and taller)?  215-85-16s series tires are about a 30 inch (+/-) tire that are about 6-6.2 inches wide versus a 7"(+) width for a 235 series tire.  235/85/16s should put you in the 31" inch range.  Several companies offer a good A/T tire in this size range.  

More diameter with less rolling resistance, should get you more MPGs with all else being equal.  Keep in mind once you over size your tires, your odometer will continue to provide feed back on based on the stock wheel diameter because it doesn't re-calibrate for the new ratio you have created.  You have to factor this info into your MPG computations.   BLUF:  with taller tires you are covering more distance with each revolution of the wheel = possibility of obtaining more miles per gallon IF the rolling resistance is reduced.  

I need you to pay careful attention to that "should get you more" mentioned above - a lot will depend on the nature of your terrain and driving style.  Taller tires equate to higher gearing and your acceleration suffers, depending on how much larger you go, you can find the evhicle staying in the lower gears longer and end up using more fuel rather than less.

Flat terrain, a lot of highway usage you might be fine, hilly terrain, lots of traffic it might work against you.

Well I was wanting to put 15" wheels and tires on it but since everyone is stating that the wheels wont clear because of the calipers then I guess I wont. I really dont want to put any money in it to get the better tire on it. If I was to go to a taller-skinnier tire then that just increases the roll over chances and I dont want that, especially when my girlfriends drives it. I have seen what happens to vehicles when you put wheels spacers on and the thought of doing that to the ball joints and other components is not my thing. So I guess we will be getting rid of it here in a couple of months for something better....Thanks for the comments...

Oh and yes my Tahoe does get the gas mileage and I am very glad to say that I Love my Tahoe...

The tahoe cost of ownership over 100k vs the GV is not even in the same ballpark. The GV is remarkably reliable. Alternators, transmisions,wheel bearings, blower motor resistors and transfer cases are very common problems. Also, In equal driving conditions, a tahoe will not get better mileage.

Well I was wanting to put 15" wheels and tires on it but since everyone is stating that the wheels wont clear because of the calipers then I guess I wont. I really dont want to put any money in it to get the better tire on it. If I was to go to a taller-skinnier tire then that just increases the roll over chances and I dont want that, especially when my girlfriends drives it. I have seen what happens to vehicles when you put wheels spacers on and the thought of doing that to the ball joints and other components is not my thing. So I guess we will be getting rid of it here in a couple of months for something better....Thanks for the comments...

Oh and yes my Tahoe does get the gas mileage and I am very glad to say that I Love my Tahoe...

really? did that come from consumer reports? I dont think a 1/2 inch taller profile will tear a hole in the time/space continuum or cause a automobile to just flop over like a dog looking for a treat.
if thats a concern maybe a well padded hover-round is in order.

Mikerpm4X4,
What kind of mileage are you getting with the V6 now?

Mikerpm4X4,
What kind of mileage are you getting with the V6 now?

I changed the exhaust from the pre-cats back to 2 1/2 inch and now I can get 22.8 but I average 19. The merge on the V6 is terribly restrictive. I plan to switch to a manual after moab. Im hoping that will help as well.

I am getting about 18 mpg. I use cruise all the time except for up hills when I go to work. I find that the cruise just kicks it down to keep the speed up so I control the gas when I go up hill.

On the way home from Moab I got between 20-21mpg in the Zr3. I did not use cruze control. Cruze is not the best way to get mileage btw. Cruze always makes me sleepy on long trips. If you want the best mileage you need to drive like your literally pedaling it.

SWEET.... just wanted to let you all know we have it an amazing 24 mpg with our GV. I have been not using the cruise and we have not been driving over 50mph. We got 384 miles to a tank. This is awesome.....