I have an 04 Suburban. It gets about 15 mpg. I've been trying to find a way to make that better. I've heard that a K & N cold air intake would help some. But then I got to thinking about getting a performance chip for it. Does anyone have any advice on that? I don't know much a about how they work so if you could dumb down the advice, it would help out a lot more. So what can anyone tell me that would get me the most MPGs I can possibly get. I drive 128 miles round trip everyday so I've got to do something before I go broke.

 

Welcome to the forum.

12-13 in town and 16-20 hwy depending on how you drive. You can improve your mpg easier and cheaper by changing how you drive than all the aftermarket add-ons will do. Just think that if GM could get 25 mpg out of these rigs, you better believe they'd do it.

Also even if the aftermarket stuff could improve mpg significantly, stop and figure how long you'd have to drive the truck to break even.

 

I respectfully disagree with you on this. These vehicles are designed to operate within EPA standards, as far as MPG and emissions. Due to the tiered system that the EPA uses, these vehicles are classified as trucks, and don't have to abide by the more stringent regulations that are put on smaller passenger vehicles.

Now, if the EPA were to tighten the MPG regulations, then GM, as well as the other truck manufacturers, would build them to match.

Sadly, public demand for better mileage hasn't reached the level it needs for the supply side of the manufacturing to make changes. As long as they are within the limits of the regulations, they'll continue to make and sell them.

Now, as for increased, or better MPG...keeping your tires at proper size and inflation, good clean fuel system, clean cooling system, and properly lubricated engine components will keep your mileage at it's optimum level.

I agree with driving styles...I can get consistent 19.5 and higher highway MPG, yet my wife can't. I crest a hill, and put it in neutral, so I can coast down, using less fuel. I also use the cruise control on flatlands quite often. Driving like there's an egg under the right pedal is key...don't stomp on the pedal, ease your increase to the speed limit, and your numbers will increase.

I also use Seafoam at least twice a year, to keep the upper intake system clean, as well as the lower. I won't use it in the oil if it's a higher mile, used vehicle, as it could dislodge deposits that were actually clogging gasket leaks.

In my Tahoe, the PO always used synthetics, Royal Purple, to be exact. no sense in changing since it's the best on the market, and has the best results in the long run.

Above, you'll notice that I said properly sized tires. Going with larger than stock will eat up your gas. You could go with a set that are slightly smaller in diameter, but then you'd have to have the speedometer calibrated for them. If you do go smaller, you'll have better numbers as well.

GM could easily get better MPG out of these vehicles, but they won't because public demand and regulation isn't in place for it.

With gas prices increasing as they are, perhaps things will change in the near future.

 

Keep the stock intake and use a good flowing filter with great filtration. A chip flash won't increase mileage without harming performance.

If you're looking for something with better mileage as a DD vehicle, then find an econobox...

My DD is a Lincoln MK VII, which gets about 26 mpg at optimum cruising speed, which is 55-60. 65 actually causes your vehicle to consume more fuel. This car now has 240k miles on it and still going strong...with great mpg for it's engine displacement and size of vehicle.

 

I agree with 73shark AND jplinville If GM could get more without compromising performance they would. (performance primary being the ability to tow, put 4000 lbs behind that Lincoln and mpg would be severely impacted, but not so much the the truck / SUV)
As of 2011 most all GM vehicle require synthetic oil for better fuel economy..
driving habits by far make the biggest impact that you can see...
(I would not recommend shifting into neutral thou for safety)
I have found keeping the tachometer under 2k when accelerating from a stop helps a lot.
Maintain your vehicle is also very important as stated above...

 

And use your brakes as little as possible.

Not sure about the smaller diameter tires since that's the same as a lower axle ratio (numerically higher). This could improve or worsen mpg depending on a lot of variables. There was a lot of anecdotal evidence when the GMT900s came out that the folks w/ 4.10 gears were getting better mpg than those w/ 3.73 gears. This is counter to conventional wisdom since engine rpm would necessarily increase.

When you analyze the weight & Cd and the energy req'd to overcome these factors, 25mpg is about the max for these trucks w/ a naturally aspirated IC engine. Speed is the big killer as drag increases w/ the square of the speed.

 

True...these vehicles, at highway speeds, have all the aerodynamics of a dairy barn from the side.

I'm a natural Dodge fan, but I bought the Tahoe for my wife to help her get all the kids where they need to go in comfort. Dodge has a nice MDS engine (multi-displacement system), meaning that it will run as an 8 cylinder or a 4 cylinder, depending on demand input from the driver. When put in the 1500 series Ram or the SUV, it increased MPG by 10-20%. I'd like to see more of this technology used in trucks and SUVs.

 

2007 and up have AFM (V8-V4) operation. Not sure how much it helps.

I read that the NBS Cd is .36 which isn't terrible.

 

I'm not sure what to take from all of this. I don't tow anything and I drive in Houston traffic everyday. The tires are stock. And I drive with the pedal to the floor. I was just hoping there was some way to improve the mileage. From the way everyone is talking, it's not going to happen. Oh well then. I like the room so I'm not changing. Thank everyone.

 

Changing that is the cheapest, least invasive and most effective way to increase your MPG.