New Member - 06 Silvarado 4.8L
 

I have an '06 Silvarado 4.8L and am looking for ways to improve mpg. I'm finding lots of adds for chips that promise 7 and 8 mpg but concerned about how they do it, will it harm the engine? I would really like to hear some first hand testimonials from those who have used them and would recomend a particular chip or tunner.
Thanks for your help,
Pappy

Yea, usually those gimmicky type of things do very little or nothing at all. Many of them do very little or nothing at all. I once saw a "Fuel Saver" that was literally just 2 LEDs and a capacitor. They were asking $20 for it and the internal components could be purchased at radio shack for around $2 and even then, it took power to illuminate the LEDs.

Many of these companies don't have to answer to anyone for their claims. Given that, they can say what they want and advertise what they want without justification of those claims.

If I were you (and it was my first step), I would get a scangauge 2 or an ultragauge. These are incabin computers that will show you your MPG and many other parameters of your vehicle. The first way to drive efficiently is to know how you are actually doing.

Good luck to you whatever you decide to do.

-beef

Usually, those chips do not increase the mileage. What generally happens is you put the chip in believing that the mileage will increase, and you subconsciously drive in a manner that will achieve better mileage. Save the $400 on the chip, and just learn to drive it better to begin with.

The best device you can buy would be a Scangauge II. It will allow you to monitor up to 4 engine parameters at once, including instant MPG. This helped me get better mileage in my 98 GMC K1500. When driving you can see the instant feedback as to what you're doing is good or bad. If you shop around you can find a new Scangauge for as low as about $140.

I like setting up an X-gauge with "trip" fuel economy so that I can see how my daily drive differs with driving style and seasonal weather. it resets the "trip" after the engine is off for around 3 minutes.

I am pretty sure it tells how to do this in the owner's manual. been a while since I had to fool with it.

I too use a current trip average X-gauge.

rathmann, what is sold for your truck is not a chip but a tune that is programmed through your OBDII port. The tuning services and handheld downloaders I've seen are marketed mainly to the sort of people whose pedal is always floored and who don't actually track their fuel economy in a meaningful way.

Aftermarket tunes change the compromises that are made by the OEM engineers. If they produce real results with fuel economy (and I can assure you that you're not going to get a 7MPG increase in a full size truck), the variables that they adjust might affect longevity, performance, driveability, or emissions. Based on marketing and reports from actual users I think the most noticeable things they do are to mess with drive-by-wire throttle actuation so that the throttle opens more with less pedal input, and make the automatic transmission more likely to downshift. They often adjust ignition timing and fuel injection too. If your truck has displacement-on-demand aka cylinder deactivation aka AFM (Active Fuel Management), a tune would likely adjust that too.

One thing a tune could do that would really help is enable the latent lean burn program that may be in the computer but disabled. I know older GMs had it but I don't know if/when the stopped including it, since it's disabled for emissions reasons.

I would not recommend a handheld downloader for your truck. If you were going to tune it, whether for fuel economy or for speed, you should hire someone who uses EFILive. EFILive is a very powerful system for custom-tuning modern GM engines. A good tuning company can provide you with a data logger that will record your driving habits so that, in combination with your stated preferences, they can tune for your driving of your vehicle in your conditions.

I never have the cash to invest in that sort of thing. Using only increased tire pressure and efficient driving techniques, I have significantly improved the fuel economy I get from my 2002 GMC Sierra 1500 5.3, which is nearly the same vehicle.

What kind of driving do you do? City, highway, rural, etc? Heavy or light traffic?