Mpg and tuner

breese1234

Active Member
Joined
Nov 17, 2011
Location
Hudson, NC
Hi, I have a 99 z71 4x4. I want to increase my fuel mileage. How good are the tuners for them. Are they worth the $300+ you pay for them. What kind of gains can I expect. Also, which brand is the best for mpg. Thanks.
 
breese1234 said:
Hi, I have a 99 z71 4x4. I want to increase my fuel mileage. How good are the tuners for them. Are they worth the $300+ you pay for them. What kind of gains can I expect. Also, which brand is the best for mpg. Thanks.
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I do not think you get the crazy gains on a gas engine like you do on a diesel engine, but with a custom tuner you can get some good gains. EFI Live is the one I keep hearing about
 
But do they pay for themselves?
 
On a mostly stock half ton with a 5.3, you can get some nice gains. Some extra timing, tweaked fuel tables, and some transmission shifting adjustments can make it feel like a completely different truck. You might pick up 1 or 2 mpg, but it'll take a while because after a tune, your right foot is going to get heavier for a while :D

EFI Live/HP Tuners > any canned tuner.
 
Croatan_Kid said:
You might pick up 1 or 2 mpg, but it'll take a while because after a tune, your right foot is going to get heavier for a while :D
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breese1234 said:
The guy told me I would go from 13 to 19mpg. Does this sound right. If so, it's probably worth it.
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50% increase? Highly highly unrealistic. 1-2 mpg. Not sure what it gets stock but if it's not getting stock mileage, tune up, check pressure regulator/fuel delivery, plugs, tire pressure, alignment, brakes for dragging calipers / drums, wheel bearings, etc
 
If it gets 13mpg and is stock, there's something wrong with it. It should get 16-18 mpg. My truck was a 4.8/5 spd. Got 16 mpg stock. Once I did 05+ electric fans, intake, exhaust, and had it tuned, I could manage over 20 mpg. It was also a reg cab long bed, whereas yours is probably an ex cab short bed with an automatic.
 
Croatan_Kid said:
If it gets 13mpg and is stock, there's something wrong with it. It should get 16-18 mpg. My truck was a 4.8/5 spd. Got 16 mpg stock. Once I did 05+ electric fans, intake, exhaust, and had it tuned, I could manage over 20 mpg. It was also a reg cab long bed, whereas yours is probably an ex cab short bed with an automatic.
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I wouldn't be so hasty. How you drive it has a lot to do with what sort of mileage it's going to get, and I don't just mean how heavy your right foot is.

For example, we have an Explorer. If I drive it back and forth to Durham, it gets 21-22mpg. It's all interstate, and because of traffic, you rarely see the high side of 65. If I drive it to Asheville, it's going to do 18-19. There's maybe some elevation change, but there are also long stretches of 70+ mph. The faster it goes, the worse the mileage is. If I drive it back and forth to Raleigh? 12mpg, all day long. Surface streets, stop and go, lots of iding, no long legs at a constant speed.

That's why you'll see guys who live out in the country with old diesels that get an honest 24mpg. They pull out of the driveway onto a 2-lane and do 45mph for 10-15 minutes until they get to town, then shut it off and do it all over again later.
 
I drive my truck super easy. It does have a k&n filter in it. Other than that, it is stock. I took the bigger tires off. They were 285/70/18s. I have only been getting 13mpg. I guess I'll try new plugs
 
Check everything on that list I made..

Edit - check the plugs, they may not need to be changed. Some people claim the Platinum+4 plugs boost mileage. I'm not so sure myself. They also sell "power pulse" plugs that claim mileage & power boosting.. supposedly Dyno testedt. I was going to try a set and see..
 
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LS based motors seem to do best with a Delco or NGK plug based on my experience. I ran some Bosch plugs one time and legitimately lost 1.5 mpg...it was weird. I know it shouldn't make any difference, but it did. Weird, right?

A good tune up never hurts if you haven't done one lately. Plugs, wires, clean the MAFS, clean the air filter, and a new fuel filter. A lot of people neglect the fuel filters for some reason.
 
how much of your driving is in town traffic back roads compared to open interstate. my truck although a diesel has a pretty damn big gap in fuel mileage between backroad/town and hooking up to a trailer and going for 3-6 hours on interstate.
 
x2 on what CK said - literally everytime ive tried other than NGK in LS, its a dog.

My 2 cents is this: I dont know how many wrenches you own, but pulling the 5.3 is very easy. Installing a cam, is very easy. A really nice "fuel econ" cam can be used for less than 300.
 
I have the diablo intune 3 platinum. I have the fuel economy tune now and so far I like it. I've tried the other tunes but wasn't really impressed. The 93 tune gave it more high rpm power but made it feel week at low rpm. Which is opposite of what I need. The fuel economy tune feels great at all rpm but really makes a difference in low rpm. I've seen 1.5 mpg improvement but I don't think it will pay for it self. That's not why I got it though so it's ok. I'm about to do a regear and it will let me flex the speedo.
 
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