With mine I'm getting 15-16 in town, 20 highway with 3.55 gears and 285 tires.

 

Well mine is getting 13.5 mpg hwy and 13 mpg city and that is with the Hyper-Tech programmer set at fuel economy.... If I leave it stock it gives me about 10.5 mpg... I have the 4:10 gears... Do you have any kind of a programmer or chip in yours, I can't understand why it's all I'm getting with my programmer...

 

And what size tires are you running? Just curious. I suspect my numbers are close to yours. I normally dont fill the tank on mine so I dont have any real numbers. Guess I should just to have some baselines.

 

Jiveturkey, I have the Nitto terra grapplers 305-70-r16s with 4:10 gears

 

Thanks

 

Everything I have is in my signature here. 3" Downpipe, 6637 intake, Stage I injectors, and a PHP chip.

On my last trip down to cali on the interstate I got 20.5 mpg and I was using my 140hp Extreme setting on the chip the whole way.

I used to have a economy tune on it, but I noticed I could get the same mpg's from the 100hp and 140hp tunes as long as you keep your foot out of it. It's more about driving style than the tune.

My truck used to be a dually with 4.10 gears and I was getting about 14-15 in town and 18 or so highway, that was just with the 6637 intake, no other mods and 235's for tires.

 

I have 4.10s and 285 75 16 tires and get 15 mph mixed driving. I have knocked on the door to 20mpg driving 55mph. Not bad for a one ton crew cab. I would think the money you would spend on gears would buy a lot of fuel. I also tow a lot and love my gears.

 

May as well add to this hodge-podge...

getting about 14-15 with 4.10's, but drops to 8 ish if I'm towing (granted I like to keep it about 65). Sound about right?

 

I averaged 15mpg driving from NC to CA, then up to Oregon last January with 2,000 pounds in the bed (under canopy) and my wife's Cobalt on a trailer behind.

I had the cruise set at 70 for most of the trip.

 

Yeah, 4.10's are a lot nicer if you're towing.

I also wanted to add that I use a fuel additive every tank. In the warmer months I use the Powerservice grey bottle, in cold months I use Powerservice white bottle (w/ anti-gel).

The truck runs a lot smoother and gets better mileage when I have the additive in there. When I don't use the additive I can really tell a difference...

 

So do you suggest I get the php chip and not swap out the 4:10s to 3:55s or go to the 3:55s along with the php chip ?

 

3.55s with a php is ideal for best mileage. but the cost of buying a 3.55 axle or the gears and putting them in, it would take you a while to off set the cost.

Take into mind your driving. like do you drive in the city more? ive heard 4.10s are better in the city. Ive got 4.10s the mileage is alright for what mods i have. but i like to drag race to every light thats why my mileage is down.

But i dont know what mods you have on your truck. but if you want to go with a php chip. Youll have to go with a 3 in dp, intake and gauges.

 

If you do a lot of highway driving and not much towing 3.55 gears will be a benefit for mileage.

Switching to a different chip isn't necessary, it depends on your preferences and there are lots of good custom tuners out there (PHP, Gearhead, TW, Beans, etc).

 

I think I'm going with 4.10s and I'm getting 38s.

 

What about throwing a 4 inch lift and 4 inch bigger tires. That should help??? Any idea on the cost of a good lift kit?? I have no idea where would be a good place to get a complete lift kit. In order to put bigger tires I have to do a suspension lift to get seperation on my underbody tool boxes.