SimpleManLance

iTrader: (9)

just bought a 2005 cc 1500 z71 on friday. this truck will be my daily driver/family wagon.


it has 3.42 rear end and 285/70/17 tires on it the goal is to get the best MPG possible but still be able to hold its own. only drove it 20 miles on a 55mph road with 5 stop lights on it. i netted 17mpg (stock truck with out speedo corrected).

MODS: (to be installed)
pacesetter LT headers and ORY.
BB tune (87oct)
elec fans (factory)
k&n intake
flowmaster muffler (came on truck, and is pretty quiet)
trailblazer stall
built trans

according to this calculator http://www.chevellestuff.com/tools/rpm_calculator.htm
@ 70mph i will be at 1722 RPMs
@ 75mph =1845 RPMs
@ 80mph =1968 RPMs

so my guess is i need a motor that has tons of tq so that at those rpms the motor will have some power and not be a dog. looking to get better then factory MPG.

will a torque cam for a 5.3 be enough to push this heavy truck or should i opt for a torque cammed 6.0? budget is $2000.

What are your ideas and thoughts.

fastnblu

iTrader: (2)

Well u asked, I've got a few thoughts. You picked the heaviest in the fleet, so the good gas mileage title is kinda an oxymoron to me. Just sayin.

Drive it some more, or go thru a tankful, then do a full tank on gauge to a full tank, then calculate. I think that'd be more accurate than a short run. I think the 3.42s will help tho.

A stall, & u want better than stock MPG figures? That right there raises your starting RPM's by ~600 rpm.

That stuff aside, what mods are on the truck already, beside the Flowmaster? Cause a $2k budget sounds like it'd be real tuff, depending on what u have for mods already, or depending on how crazy mods will be like the K&N & tranny as outlined below. I put estimates, if ya already have em, so be it, or if ya get a deal, it's a different story.

pacesetter LT headers and ORY. $400
BB tune (87oct) $2-300
elec fans (factory) $100
k&n intake panel or CAI? - $50 or $200
flowmaster muffler (came on truck, and is pretty quiet)
trailblazer stall $100-200 junkyard or a reworked CircleD? $395
built trans Not sure what you're goin for here buddy, just a shift kit & servos, cause u know how much a FLT costs.

A torque cammed 6L for MPG? If ya said for a runned, OK, but if it were my $, just jam a torque cam in the 5.3. I know someone is gonna tell me their 6L gets this, & if it's GMCtrk, well you're running 4.10s & a 3600 stall, so you're out.

Lance I do wish good luck, & I hope ya get what ya want MPG-wise. But that weight is gonna be your nemesis. It looks clean tho.

AKlowriderZ71

iTrader: (22)

Here's what I'd say.

Smaller tires(narrower=less rolling resistance)
cam the 5.3 for torque
stock mani's & cats(can get into closed loop faster)
CAI of your choice
87 octane tune(BB is good, discuss your goals with him)
consider lowering the truck and put a lip under the front bumper(reduce drag)
Install a vacuum gauge, try to stay in as much vacuum as possible at all times
basically, teach yourself better driving habits.

The e-fans won't improve your mileage(in my experience), but will cost $$
built trans isn't necessary, unless yours goes ****-up
TB converter will hurt your mileage

fastnblu

iTrader: (2)

I never even thought of the stock man. / cats thing - closed loop. But I've been running headers since I had 16k, so stock was long ago.

Lowering I think did help me. IMO, a tonneau helps, but not what mine cost, so cost recovery vs MPG gains offset poorly, I did it for storage, security & a look. If cost there's a concern, there are cheaper, so I think that helps MPG too.

E-fans didn't do much, if any. Actually, they lower parasitic, but electrical draw places demands that affect mileage. I spent the coin already on e-fans, but I like how it creates room, so they stay.

****-up.

dlt76028

iTrader: (13)

same truck I got man, and I love it. If you want the best mpg, I wouldn't put a cam in there. even if its a little tq cam, it's going to want more air and more FUEL, and I've never seen a aftermarket cam on a mild setup put more tq down at a lower rpm then the stock cam...

48548

On my 5.3 2005 ECSB silverado 4x4, I get about 17-19 average... With a tune, volant cold air intake (ram air tube behind tow hook) and a flow master exhaust... I also have the L33 aluminum engine and it came factory with the electric fans. I am not sure how much heavier your truck is than mine. I did install a transgo hd-2 and vette servo, but don't think that helped gas mileage any. I wouldn't complain the gas mileage you saw. Also these are only 4l60e's if I wanted better gas mileage I would get a 6l80e for the extra gears to help and a better tranny as well (better over drive also). Maybe the newer trucks also with active fuel management also helps by only having to feed half the cylinders also....

Beatdown Z

iTrader: (18)

All this, except for the CAI. Just modify your stock box and make your own "free-flowing" tube.

If you want tires the same height, but narrower, look for some 235/80/17's.

andrew383

iTrader: (14)

As mentioned before get a smaller tire..I had 285's on mine for awhile and then went to 255 75 17's and i could def tell a difference between the 2..

Id go with some 1 5/8 headers,cai of some sort,ls6 cam or similar cam,tune,smaller tires,

AKlowriderZ71

iTrader: (22)

I forgot to mention this about selecting tires for mpg. You want 4 ply tires, not 6 or 8 ply tires. Also, do not select tires with aggressive tread, or large voids in the tread. Do NOT have them siped. Ask for tires with low rolling resistance and a high treadwear rating.

SimpleManLance

iTrader: (9)

all the things on the "MODS" list i have except the black bear tune. they are just not installed. i just dropped the trans off at the local guy to build it to handle a cammed 6l(just in-case). the $2000 was above and beyond the things in the MODS list.

the window sticker says 15/18mpg on it. im hoping with the right driving habits i can do 15-17/18-20mph. i just want to have fuel economy in mind when i add stuff to the truck. i dont really want to give up MPG, if anything gain them.

dont really want to swap tires or lower the truck. i actually plan on leveling out the truck because the front sits lower. so the torsion bars will be cranked some. i got to be able to climb the sand dunes.

im worried with the 342s and the bigger tires it will be a dog on the highway. i dont really want the truck to have to downshift to climb a incline. thats why i was thinking more torque. that way it has the power for crusing to push itself and a little extra when i want to hammer down. im not going to drive it like a grandpa 24/7.