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Upgrades for better gas mileage??


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#1 Chad H

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Posted 15 February 2004 - 09:50 PM

Hey guys,
My truck isnt getting just great gas mileage. I dont need better but I would certainly like it! Below are a list of my modifications. I was wondering what else would improve that? Does anybody make electric fans for a '04 or anything?

Thanks,
Chad

Volant Intake
Flowmaster Exhaust
Magnecore wires w/ NGK plugs
Westers pcm coming....
2012 Chevrolet Tahoe Z71
RCD Leveling Kit
BF Goodrich A/T's

#2 OBXSpook

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Posted 15 February 2004 - 10:32 PM

Well the westers should help, as long as you told him you were more interested in MPG than performance....electric fans should help too...

#3 Chad H

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Posted 15 February 2004 - 11:05 PM

I did just that, about the Westers tune. Where can I get a set of electric fans? And will they bolt right in? Can you give me a link for some info on these. :shakehead:
2012 Chevrolet Tahoe Z71
RCD Leveling Kit
BF Goodrich A/T's

#4 NothinButBowTies

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Posted 16 February 2004 - 12:24 AM

The electric fas out of any F Body GM (Camero, TA, Firbird) will work fine with little modifications for around 150 bucks. You will also need a controlling unit for about 50 bucks.
Flexalite makes a kit for our trucks but it is alot more money. I think it is in the 400's.
2003 GMC Sierra SLE
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180 TSTAT
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#5 d2alio

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Posted 16 February 2004 - 12:32 AM

exactly how "much" are you guys improving gas? I mean, I have a 2003 GMC Sierra 2500HD with Vortec 6000 and I just drive around locally (maybe 20 miles a day.. IF THAT) and Im going through a full tank every week/week and a half. I want to put an exhaust (thinking about Gibson) and K&N Air Intake... but then at the same time im going to lift my truck and put some 35"ers on there... so will my mpg still be improved?

#6 raiste

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Posted 16 February 2004 - 03:11 PM

Just playing devil's advocate here: You may be improving gas mileage, but how long is it going to take to get a pay back from all those mods? 50,000 miles, 100,000 miles?

It may not matter, but wanted to add some food for thought.

#7 OBXSpook

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Posted 16 February 2004 - 03:20 PM

Well generally with the lift, you are gonna lose some gas milage....big meats make a lot of resistance...rolling, and aero. With my 8.1L with my lift and 315's I was seeing being 11-12 mpg....now that I added the westers 93 tune, I get around 10. Supposedly the new fans flexalite says will add 1-2 mpg, don't quote me on that but I think that's what they say, and around 17HP. The way I look at it, if I wanted to get good gas milage I'd ride a bike.

#8 intruder217

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Posted 16 February 2004 - 04:21 PM

I can't see how electric fans are gonna save gas. If your original fan clutch is working I think it is the best setup you can have: All the cooling you need when you need it, disengaged when you don't, and no complicated wiring or expense of fans and thermostats. Plus, when they kick in they draw serious amps, which makes the alternator work which consumes additional fuel. (my 2 cents)

#9 Machine

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Posted 16 February 2004 - 06:15 PM

exactly how "much" are you guys improving gas? I mean, I have a 2003 GMC Sierra 2500HD with Vortec 6000 and I just drive around locally (maybe 20 miles a day.. IF THAT) and Im going through a full tank every week/week and a half. I want to put an exhaust (thinking about Gibson) and K&N Air Intake... but then at the same time im going to lift my truck and put some 35"ers on there... so will my mpg still be improved?

Hi,

I really didn't notice a great improvement in gas mileage with the addition of a K&N and Catback on my Escalade (before the addition of the supercharger). Maybe .5 mpg. But the moment you lift your truck you will change its aerodynamics –you’ll now have alot more air going under the truck. And the big 35's you’re installing will require alot of additional energy to move them, too. You’ll most likely have to re-gear in order to get your mileage anywhere close to where it was. I put 305’s and a lift on my 2500HD and I lost 2.5 mpg.
2011 Suburban Z71

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2003 2500HD LT, LB7 Duramax, CC; Quad / Juice, MBRP 4" Exhaust, Rancho 6", BFG KO 315's, Auto Meter Pyro and Boost.
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#10 OBXSpook

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Posted 16 February 2004 - 06:38 PM

I can't see how electric fans are gonna save gas. If your original fan clutch is working I think it is the best setup you can have: All the cooling you need when you need it, disengaged when you don't, and no complicated wiring or expense of fans and thermostats. Plus, when they kick in they draw serious amps, which makes the alternator work which consumes additional fuel. (my 2 cents)

regardless of whether or not the fan clutch is engaged, the fan is always spinning, whe you take the fan off, it's that much less resistance working against your eninge. Supposedly that's where you gain your mpg, and hp.

#11 Tucson_02Silverado

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Posted 16 February 2004 - 07:21 PM

The MPG/HP/TQ increase going to electric fans is from removing 30-35lbs of physical mass + the reciprocating resistance "mass" of the fan off of the total engine reciprocating mass.
2002 Chevrolet Silverado 1500 5.3L LM7(T) 3.73 Extended Cab SWB 2WD

#12 redvett

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Posted 16 February 2004 - 07:41 PM

I can see two gas guzzlers in your list of changes.
285/75/16 Bridgestone Dueler M/T's w/ Torsion bars jacked
On the way: Warn brushguard, Warn 9000lb. winch,
Without the calibrations changed you are going to have worse mileage and performance. Your 2 sizes larger tires is putting the engine lower in the power band hurting your mileage. Adding weight is another. Cutting wind resistance helps.
Also put a tonneau cover on it will help about 1 mile per gallon.
:shakehead:
My 2004 1500 LT 4x4 will get 19-20 MPG on a 400 mi trip in cold Michigan weather.

#13 intruder217

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Posted 16 February 2004 - 09:04 PM

The MPG/HP/TQ increase going to electric fans is from removing 30-35lbs of physical mass + the reciprocating resistance "mass" of the fan off of the total engine reciprocating mass.

First of all fans don't reciprocate, they rotate. I'll be surprised if the plastic fan and aluminum clutch on my 99 Suburban weigh more than 8-10 pounds. And, when disengaged it is barely turning, just being dragged along by the viscous nature of the fluid. You can hear mine cut in and out when the engine is idling warm and the change is noticeable. I'd love to hear some concrete (read "before and after") mileage data and the actual parasitic loss of a clutch fan that is almost always disengaged at highway speeds. Automotive engineers still seem to hang an engine driven fan if it can be pointed at the radiator. I bet you can get better value by spending the time and money elsewhere if better mileage is the goal.

#14 d2alio

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Posted 17 February 2004 - 02:37 AM

well i wouldn't have bought a truck if I was "that" worried about the gas. It'd be nice to not have to gas up every week for such short trips, but surprisingly for my FIRST BIG VEHICLE it's not as bad as I thought it'd be and since I was all ready expecting to gas every week it doesn't totally drive me crazy. A lot of places I go are just about in walking distance so I just walk over anyway. My work is about 15 minutes away by driving or half an hour if I take the bus. For a little while I was considering taking the bus to work (LOL) since it's a clean city bus and drops me off right in front of work and in front of my apartment... was an option, but Id rather just drive. :shakehead:

#15 Chuckster

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Posted 17 February 2004 - 08:29 AM

The MPG/HP/TQ increase going to electric fans is from removing 30-35lbs of physical mass + the reciprocating resistance "mass" of the fan off of the total engine reciprocating mass.

First of all fans don't reciprocate, they rotate. I'll be surprised if the plastic fan and aluminum clutch on my 99 Suburban weigh more than 8-10 pounds. And, when disengaged it is barely turning, just being dragged along by the viscous nature of the fluid. You can hear mine cut in and out when the engine is idling warm and the change is noticeable. I'd love to hear some concrete (read "before and after") mileage data and the actual parasitic loss of a clutch fan that is almost always disengaged at highway speeds. Automotive engineers still seem to hang an engine driven fan if it can be pointed at the radiator. I bet you can get better value by spending the time and money elsewhere if better mileage is the goal.

The Fan IS a load.... and it does not kick in and off at idle.... It needs to be running all the time at slow speeds.. It it did not your air conditioning would never work.

That load on the engine is there when pulling away from a light every time..

They say it is temperature controlled I say that is BS.. It is RPM controlled... Rev your motor to 2000 rpms and hold it there.. You will hear the fan slowly disengage.. However It is STILL spinning and imparting a load on the motor..
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