I had a lbz ( i was on this site quite a while under a different name when i had it) but i sold it and now ive got the lly. i spend just about all day on the hwy so fuel economy is a BIG importance, so far it looks like im getting lil over 17mpg with 15k miles on the clock. running 265 tires. whats the combo yall are squeezin 20mpg outa these things. Basically

1. Who makes the best intake setup, ive seen alot of different ones listed
2. do i need a 4" or 5" MBRP turbo back if i want to run 13's in the 1/4 this go around at some point
3. ive read about gaining mpg changing the lly fan to something else?
4. now, on the tuner, i want to make ALOT of power but i want to be able to change tire size so i can fix the odometer for mileage deductions. if this means i have to stack stuff thats fine and if i need to upgrade the tranny at some point thats fine also, i just dont wanna buy stuff twice. but mpg is my #1 priority. whats your thoughs.

boy yall are alot of help:p:

Any opinions on the power pda banks setup, i can get great deals on banks stuff now, any personal results with there ram air intake? and i couldnt tell if the pda changed tire size on the truck or only on the pda as far as fixin speedo, if its only on the pda, will it stack with a programmer that fixes the speedo?

Do some research on the predator. It seems to be pretty popular for the lly and I myself am happy with it. I found that if you want to increase your mpg, just go easy on the go pedal. Programmers can help but it ultimately depends on your driving habits. JMO

i might use something like that to stack with a big programmer but definatly dont want one for my primary, ive had one of them before, it was ok for a light duty tune. and i would have to say ive seen programmers make a big difference in fuel economy, my foot wont help interstate mpg.;)

PPE for power, minimum 4" turbo back, Banks is all hype no hop. Swisscheese the stock airbox. Boost controller or fingerstick.

A custom tune by Kennedy Diesel gets my vote. You'll need a built trans before running anything serious.

I agree a custom efi live tune can actually help. I've been lazy and havent really worked on anything, but I'm running someone elses tune that about 40hp and I've noticed about a 1-1.5mpg increase. Thats actual increase. I think anything above that is just wishful dreaming....Unless you get your 5spd to 6 spd mod for the ally, lower the truck, take off the bed, etc.

Do the mods for the power, not for the mileage. It takes a LONG time to just break even on mods for mileage, unless you're driving thousands of miles a week... mostly 'cuz there isn't really anything you can do to get more than 4 or 5mpg over what you're getting now, realistically.

I'd agree with ben, keep the factory airbox and swisscheese it. Do a search.

4" exhaust is plenty big for 13's and even 12's. 5" is all fine and good, but if you're trying to save $$$, not worth it.

Screw the Banks setup; if mileage is a top concern, but you still want the option to make big power, you want EFILive. $550 for V1, and you can load any tune from pure mileage to 500+hp on factory hard parts. I had the banks 6gun on my truck a while back, and it did little to nothing for mileage.

If you want to run 13's, or anything more than 80-100hp over factory, you're going to need a built tranny, which'll run you anywhere between $2k and $6k, depending on who's you use and who does the labor. Your choice.

$500 for an exhaust which might get you 0.5-1mpg improvement (at best) will take you upwards of 55,000mi to pay off (17mpg vs. 18mpg @ $2.75/gal).

$550 for a Banks chip which migh get you 1-2mpg improvement (very unlikely) will take you upwards of 36,000mi to pay off (18mpg vs. 20mpg @ $2.75/gal).

There is one thing you CAN do though; when it comes time for new tires, go with something a little bigger (as big as you can fit without having to lift or turn t-bars). 285/75/16s fit fine on my truck with no lift, no t-bar turning, and minimal air dam trimming. As long as you keep off the hard accel, bigger tires will help your mileage considerably, and there's no cost if you need new tires anyways.

I heard that the 6-speed tranny runs the same RPM as the 5-speed at 75 MPH.

yeah in 5th gear :rolleyes:

I too have a Kennedy tune. I have broke 22 mpg with it, but its only about 50 HP. Tows great though.:)

Do some research on the predator. It seems to be pretty popular for the lly and I myself am happy with it. I found that if you want to increase your mpg, just go easy on the go pedal. Programmers can help but it ultimately depends on your driving habits. JMO

exactly. well put!!:beerchug:

I heard that the 6-speed tranny runs the same RPM as the 5-speed at 75 MPH.

Really? My maths tell me otherwise...

Here's the complex way of figuring it:

662(tire)rev/mile x 75mph = 49650(tire)rev/hr

49650(tire)rev/hr / (60min/hr) = 827.5(tire)rev/min

827.5(tire)rev/min x 3.73(axle)rev/1(trans. rev) = ~3086.6(trans)rev/min

~3086.6(trans)rev/min x [5THGEAR] 0.71(trans)rev/1(eng)rev = ~2191.5RPM

~3086.6(trans)rev/min x [5THGEAR] 0.61(trans)rev/1(eng)rev = ~1882.8RPM

I see's 300+RPM difference, I dono about you...

pred on 40hp and a boost stick can nab me 20-21mpg @ 55mph using cruise control

but for normal highway driving (passing, 60-65mph) i'll take a good solid consistant 18mph

i dont know if the big tires hurt or helped on my 06 because it had 300 miles on the truck when i put the 305's on it so it was still breakin it.

you think the bigger tire helps fuel economy? and to what point, as in, how big is to big till it reversed the affect, i personaly wouldnt mind having a 4" lift and some nice big tires if it wouldnt hurt economy. i would think on the big tires, going tall to a point might help but going wide is where it will start hurting huh?

i will say my 6speed definatly turned less rpms on the hwy and right now im getting about 17mpg @75-80mph

why is swissin the stock box the best? and sombody link me, i searched where i thought it would be and no results. swissin to me involves a dewalt with a nice holesaw like i did my racecar seat:D

. whats the combo yall are squeezin 20mpg outa these things. Basically



A bone stock LBZ!