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5.3l Gas Saving Mods?


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there are no "mods" that you can buy to increase MPG, sorry but any advertisement you see otherwise is a load of horse $hit..

 

 

Car Manufacturers spend tens of millions on the R&D and engineering to squeeze every bit of MPG out of their cars as possible and have for the past 15 - 20 years, in order to meet all the EPA and CAFE requirements.

 

If there were some magical parts that allowed for more MPG it would be on the car from the manufacturer..

 

 

the ONLY way to get better MPG is to learn how to drive, PERIOD..

 

slow accel from a stop

coasting to stale green or red lights

reducing speed to 45-55mph on the highway

stay off hilly and twisty roads

don't let the vehicle stand and idle (long red lights and drive thrus).

 

people that have to do 75-80 on the highway, and jack rabbit from light to light, and sit in Starbucks or McD's drive thrus for 5-7 minutes for their food will never be able to meet the window sticker MPG much less get anything better.

 

CAI, Cat-back exhaust, magic resisters and throttle body spacers, fat tires and lifts will all degrade MPG..

 

hand held tuners MIGHT help, but put you outside the CARB standards for smog and pollution.

 

 

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baulk at me if you want, but I drive a 2010 Avalanche that weighs nearly 8,000 pounds with a full tank and my fat ass in it, and I am getting over 19mpg in it, I average 580 - 600 miles per tank (and I have a 31 gallon tank thank you) and have seen as much as 734 miles out of one tank on a long trip..

 

I accel slow, I drive 55-60 on the highway, I turn the truck off at long red lights, I do not use drive thrus, and don't let the truck idle more than 1 minute most of the time, I don't use the heater or a/c unless I have passengers (I use the heated and cooled seats, or crack the windows/sunroof). I am the guy you hate to be behind on the road because you think I am driving too slow, but guess what, I squeeze every mile out of every drop of gas I can and the majority of the time you can pass me I will catch you at the next red light, and cruise on past at a consistant speed while you have to accel back up to speed and pass me again and again..

 

 

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The problem isn't having an issue with people that want an fuel efficient truck, the issue is that rather than look for a magic fix for it, just learn how to drive, and if it bothers you that much that your 8,000 pound high torque V8 truck only gets 15 mpg then you shouldn't have bought it in the first place..

 

 

 

 

 

 

There is nothing wrong with wanting the best of both worlds. I refuse to drive a car because I hate sitting that low and riding in a whimpy car. Not to mention I don't need two vehicles. But just because I want to drive a truck doesn't mean I should have to suffer with poor gas mileage. I'm happy with the mpg's I get from my truck but if someone else wants to ask some questions or see if there are any options to improve it mileage they can. Andy FYI most 1500 chevys have a 26 gallon tank. Why do people act like there is a problem with wanting a fuel effecient truck. Good Grief... :thumbs:

 

why do people purchase an 8,000 pound truck with a V8 or a high horse power Sports car or Sport sedan (corvette, charger, challenger, camaro, etc) then ask:

 

How can I get better MPG?

 

 

didn't any of you READ the damn Window Sticker when you bought the vehicle? if you want high MPG go buy a g-damn prius, otherwise STFU..

 

 

If you can't afford to put gas in your $40,000 - 8,000 pound V8 Truck with 31 gallon gas tank, maybe you shouldn't have purchased it in the first place.

 

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Heres what Ive found on my own 5.3L. If you keep the RPM under the 2K mark, you will get optimum mileage. I know people will tell you to drive 55mph, but that may or may not be optimum for your truck. I actually get better mileage at around 65 than I do at 55. But, if I bump it up to 70 it will begin to drop off again, and anything higher will drink faster and faster. I actually get the same mileage at 55 as I do at 70, but I think its because of the terrain. At 55 the truck will have to downshift to go uphill, but at 70 I guess it has enough momentum to get uphill without a downshift. Maybe thats just speculation, but according to my DIC, 55 and 70 yield the same MPG.

 

The moral of the story, keep the RPM around 18K-19K (whatever speed that nets you with gearing and tire size) and follow the other advice about coasting and slow acceleration. If you can get your truck to hit overdrive about 5 mph below your target speed, you will be doing pretty good.

 

In regards to the A/C comment, I can do without a heater in the winter on most trips becuse I live in Texas. But, theres no way in hell Im gonna go without my A/C, because I LIVE IN TEXAS :thumbs: . Seriously though, in most situations running the A/C on these new trucks will not drop your MPG much at all, if any at all.

 

Out of curiosity, do you know how much gas do you actually save with the A/C off? Im just wondering because I will not be able to experiment since it was 103* here yesterday. It feels more like I like in the Arizona dezert than in the Piney Woods of East Texas.

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I am not convinced turning off AC will help at all on the highway or any other time the engine load is steady. In stop and go traffic it might though. Regardless, opening windows is just as wasteful at speed because with the windows down you throw out all the time and money GM spent in windtunnels with the truck. That and I hate the noise you get with the windows down so anything faster than 45 or so they go up when I drive. Speed is the biggest factor though. According to the instant display on my truck I could get 2-3 mpg more on the highway running at 60-65 vs 75 or so. But fuel economy isn't a very big concern of mine so I don't do much to try and maximize it.

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The majority of my driving is stop and go surface street under 40mph as I work 6 miles from home. As such using the a/c or heat has a big impact on my mpg because it takes a lot of energy to heat or cool the vehicle for that short of a trip. I have seen a drop as much as 4 mpg in two days using the a/c on 90 degree days during that drive which is why I switched to Windows and the cooled seats as the cooling surface of the seats is far less than cooling the whole cabin.

 

But for a highway jaunt I would agree the a/c would ne far more efficient than open Windows.

 

Heres what Ive found on my own 5.3L. If you keep the RPM under the 2K mark, you will get optimum mileage. I know people will tell you to drive 55mph, but that may or may not be optimum for your truck. I actually get better mileage at around 65 than I do at 55. But, if I bump it up to 70 it will begin to drop off again, and anything higher will drink faster and faster. I actually get the same mileage at 55 as I do at 70, but I think its because of the terrain. At 55 the truck will have to downshift to go uphill, but at 70 I guess it has enough momentum to get uphill without a downshift. Maybe thats just speculation, but according to my DIC, 55 and 70 yield the same MPG.

 

The moral of the story, keep the RPM around 18K-19K (whatever speed that nets you with gearing and tire size) and follow the other advice about coasting and slow acceleration. If you can get your truck to hit overdrive about 5 mph below your target speed, you will be doing pretty good.

 

In regards to the A/C comment, I can do without a heater in the winter on most trips becuse I live in Texas. But, theres no way in hell Im gonna go without my A/C, because I LIVE IN TEXAS :thumbs: . Seriously though, in most situations running the A/C on these new trucks will not drop your MPG much at all, if any at all.

 

Out of curiosity, do you know how much gas do you actually save with the A/C off? Im just wondering because I will not be able to experiment since it was 103* here yesterday. It feels more like I like in the Arizona dezert than in the Piney Woods of East Texas.

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there are no "mods" that you can buy to increase MPG, sorry but any advertisement you see otherwise is a load of horse $hit..

 

 

I'll fight that statement any day.. sorry. I always averaged 12.9 mpg in my truck prior to me getting the wait for me tune.

 

After the wait for me tune i consistently got 13.7 mpg..

 

Added the K&N FIPK and cherry bomb extreme dual out exhaust , and as of recently i have been averaging consistant 14.4-14.8 mpg

 

The wait for me tune is for 93 octane, so i pay a little more at the pump but I now have more power, and better mpg :rolleyes:

 

As for manufacturers not taking advantage of these mods, its simple.

 

The wait for me 93 tune firms up the shifting and makes you run 93 octane.. most people dont want to do that even tho more power and better mpg..

 

Exhaust- Manufacturers build these trucks / cars for old and young... Some people want noise, a lot wont. So manufacturers have to create restrictive exhausts that dont perform like they should for better mpg and power.

 

Take a look at some of the high performance vehicles that come off the line that sound good and perform great. Camaro / vette / mustang / etc... They are built for people who like speed and want to hear performance, and at the same time get decent mpg for a muscle car.

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The wait for me tune is for 93 octane, so i pay a little more at the pump but I now have more power, and better mpg :rolleyes:

 

 

But, does the MPG increase offset the extra cost of the 93 octane? I know at my local prices it costs me about $2.50 more to fill up on 89 octane as opposed to 87. Havent calculated it yet on 92. I ran a premium tune on my ZR2, but only to help with towing and to offset the larger tires. Didnt get any better MPG.

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Other than that the only mod I can think of is swapping the whole vehicle out for a honda civic.

LOL that is exactly what I did- not swap out, but add a Civic coupe to the garage. I figured that by driving a 30 mpg car 80% of the time and my 15 mpg truck 20%, my monthly savings in fuel would be exactly 1/2 of the monthy payment on the car, including gas, but plus insurance (costing 12 gallons/month equivalent.)

 

The downside is now my truck is smelling moldy from sitting most days....

 

 

I bought a 150cc scooter for the short around town jaunts. Saved me one tank of fuel every 6 weeks. Scooter gets approx 150km/gallon of fuel. Almost so good it is not worth recording the usage. I can take back beer bottles and get almost enough money to fill the tank on the scooter, and I can take the bottles back with the scooter. I can only use the scooter from early march to early december though. Fuel savings add up to close to $700 a year. Bought the scooter brand new for $2500. I am a mechanic, so maintenance is just my time and parts.

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The wait for me tune is for 93 octane, so i pay a little more at the pump but I now have more power, and better mpg :rolleyes:

 

 

But, does the MPG increase offset the extra cost of the 93 octane? I know at my local prices it costs me about $2.50 more to fill up on 89 octane as opposed to 87. Havent calculated it yet on 92. I ran a premium tune on my ZR2, but only to help with towing and to offset the larger tires. Didnt get any better MPG.

 

 

Havent really figured it out.. But to get better mpg and know the power is there to use it , and sometimes abuse it :) Makes the minimal amt if any worth it IMO.

 

I just drove my dads new 11 silverado the other day and the amount of torque management that thing has compared to how my truck is after the tune is unbelievable. Merging on a expressway with his truck I almost feel is dangerous compared to mine, but thats a whole another topic. But my point is to still save gas and have power to use is worth it.

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Old-chevy-dude is mostly right.

 

While some things may slightly increase your gas mileage, the effects aren't drastic...And once you factor in your savings, it will take 27 years to save what you spent on the mods.

 

He's pretty much spot-on for the driving habits though. Here's what my experience has taught me:

 

-Keeping it below 2k RPM will do wonders for your in-town mileage

-Certain speeds are better for mileage, and those spots are dependent upon your drivetrain/gears/tire size. My '02 would get close to 22 on the highway at around 63 MPH with the AC on (AC off and windows down creates a lot of drag and I'd actually get worse mileage). If I upped it to 70, it would drop to around 15-17 MPG. 4x4 Z71 ex cab with 3.73's and slightly oversized tires.

-Tunes have netted me around 1 mpg on almost everything I've ever had tuned without changing driving habits

-Nothing I've ever bolted on to a truck has ever netted me enough savings in mileage to offset their cost within 5 years.

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After I installed my flux capacitor, my MPG's went through the roof!! Lol. After my BB tune my mpg range changed depending what speed I drive, before I could go 60 and get around 23-24 mpg, now it only gets 19-20, but when I go 70-80 mph I can get from 21-22.4, weird but hey, I do a good amount of highway drivin.

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  • 4 weeks later...

I'm running a 2001 Z with the 5.3 myself, low amount of mods i mostly have kept it pretty stock except and aftermarket k&n filter(not the full intake) and a magnaflow turndown. Once simple mods have been applied you can easily get better mileage if you drive the same.

Now playing with your exhaust is going to obviously take some mileage down, but you can also focus on driving the speed limit or slightly slower, then when you go up a hill dont floor it, try to catch momentum before you get there, then coast the way down the hill. Coasting to redlights instead of hittin the brakes right before you get there helps tremendously too. About a year ago when i started driving this way i calculated a total of 18 mpg on average. This technique is used by many people on multiple vehicles. Impalas can get over 40 mpg this way(i've seen it and done the math).

:D

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I have a 1999 5.3l silverado z71 4x4.... i have already put a CAI on it, but wondering what mods can i do that will be worth the money of puting them on it, to save gas? Any profitable mods?

 

 

Here is a interesting read regarding CAI's. I am not sure but I think I got it off Westers tuning site. The first line is changed a bit because of a incomplete C/P.

 

 

Decrease AIR for better mileage!! This flies in the face of what is sold out there today, but if you can decrease the amount of air entering the engine (due to the fact that this is a closed loop system as of 1996 OBD2) you will use less fuel, too. Ideally, you want to maintain the same horsepower required to combat air friction, rolling mass losses, etc...but do it with LESS AIR !!

 

Let me illustrate. A closed loop system maintains the air fuel ratio at 14.7 lbs air to 1 lb of fuel. This is maintained for idle, cruise and in some cases, even at wide open throttle.

 

If you have 60 grams/sec air entering the engine at cruise, you're using 4.08 grams of fuel per second. If the cylinder pressures are increased without creating harmful exhaust byproducts, or if these byproducts are controlled by the catalytic converter, we can gain mileage by decreasing airflow through the engine while enhancing the spark curve to maintain the same rear wheel HP.

 

On the chassis dyno, we can get vehicles down to 45-50 grams air/sec maintaining the same air fuel ratio, and same wheel HP as stock--and the overall result is less fuel consumed ! 45 g/secs works out to 3.06 g/fuel used in the same time period--or an almost 25% saving. We can't gain this in all vehicles of course--this example was resultant data from a 2007 6.0L HD 3500 GM truck.

 

This flies in the face of every aftermarket product out there claiming that it saves fuel--you will never gain mileage by increasing airflow through a gasoline engine in a mass airflow type system.

 

Because we carefully remap the spark curve with a remapped ECU, we in effect are increasing cylinder pressure without adding fuel. Increased cylinder pressure translates into more useable torque and power to maintain the power required for 'rolling resistance' of the vehicle down the road. The increase in horsepower often results in better fuel economy--although we do not guarantee mileage gains--as we cannot determine how YOU drive, and what your driving habits are.

 

Diesels are a different story...we need to stuff as much air in the cylinder as possible--and create maximum cylinder pressure at diesel injection point, use all the heat energy created to maximize pressure while keeping the total combustion event in the cylinder prior to exhaust valve opening. Smoke is wasted energy...in reality, diesels can actually run as low as 100lbs of air to 1 lb of fuel--although there's not enough heat energy created at that ratio. There's no magic air fuel ratio for diesel--leaner operation does not create damage, it just won't make power.

 

Therefore, you need a balance of fuel, best boost and proper timing to make the diesel efficient.

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