Post your engine performance mods and HP/MPG gains!!!

[Steve Cole]

I am really looking to boost my mpg but I understand the two can go hand-n-hand. I welcome increased Hp but fuel mpg is my ultimate goal. Post your exhaust/ cold air intake/ computer chip/ etc. mod that boosted your hp or mpg. Post before and after real world numbers. I'm thinking I can gain about 5 mpg with a mild exhaust mod, CAI, and chip. What are your real world results?...

Thanks!!!!!


P.S., I have a 2002 Silverado, 5.3, 4l60.

[69gmcc10]

I think you are a little optimistic on achieving a 5 mpg increase. Having owned several of these trucks a 3 mpg is ambitious but more realistic, and to get those last 2 mpg you will need to do some real fancy dancing on that gas pedal!

When I hear people talking about MPG I have a difficult time determining what they are trying to accomplish because there are several different mindsets that hunt the same animal. First, are they trying to minimize environmental impact by increasing economy. Second, Are they trying to save money by pouring less fuel it into the tank. Third, are they looking for bragging rights with there friends and don't care about the financial impact. Fourth, are they obsessed with efficiency and want to squeeze as much as possible out with or without a budget. Most people fall into one of these categories and sometimes several categories, what category do you place yourself in?

The real simple and affordable answer to this question is, keep the stock air box it draws COLD air from the fender and not warm under hood air like most aftermarket intakes. Also, the stock intake is designed to flow enough air for the 8.1 and is in no way a restriction, just buy a DRY high flow stock replacement air filter like AFE makes. 5.3L flow enough air to justify a 3" cat back exhaust system at wide open throttle, but it wont effect your economy much because that is all done at a significantly lower flowing 2000 rpm so just a free flowing 2.5" magnaflow style replacement muffler would be cheaper and be just as likely to potentially increase mpg. Spend money on a reputable tuner, hand held tuners only change change a few generic tables on your trucks computer, a computer flashed tune will consider many variables, tighten up the tolerances of the sensors on your truck, and also increase the drivability for about the same price or less of a hand held hypertech style controller.

Maintenance work will be your next best and cheapest secret for economy. Make sure to keep the MAF sensor clean and service everything accordingly.

I have an 01 1500 2wd with a 5.3 with an afe air filter. It only gets driven in town and I beat the piss out of it so mpg is not good, about 14.

I had a 03 1500 xcab 5.3 z71 Spectre CAI, no cats, stock tune and it got about 17.5 on the highway and 15 in town.

I have a 03 1500HD, 4wd, 4 door, 6.0, 4l80e, stock in town 11.5 mpg and highway 14. Spectre CAI, 4" exhaust, had electric fans (took off, no improvement on economy), custom tune from Black Bear performance and in town now I get 12.5 mpg and on the highway I get 16, 17 if drive under 70.

You can spend allot of money chasing better economy and you would be better off just converting that money into fuel and pouring it in the tank (Dollars Per Mile). But, if you want more Smiles Per Gallon there are allot of things you can spend your money on and you will probably enjoy every cent!

[Hoods69BadBowTie]

I agree the small simple things are the best way to get better gas mileage. Run some good gas and injector cleaner through your tank. Make sure you have good plugs and wires and a clean MAF sensor as well. I like a good tuner and exhaust and then a CAI if you really want one. If you feel like going all out you can swap gears out depending on what you want and what you use your truck for. I have a 2003 1500 HD with a 6" lift and 35"s I have an Aero muffler and a CAI off the internet as well as a CTS tuner as well as 4.56 gears. I get about 11-12 in town light footed and 13-14 on the highway doing 75-80 this is getting on it sometimes cause it's just to much fun You can spend a lot of money chasing better gas mileage just depends on how much and what you are after.

[Steve Cole]

Thanks for the replies! To answer your question, I am just tired of not being able to drive past a gas station without stopping! I really baby it, easy on and off the accelator but am only getting about 13.7 mpg and most of that is highway driving. I put a low profile bed cover on it already and was hoping that with a free flowing header/exhaust system, computer re-tune for mpg, and possibly a aftermarket CAI/ air filter I could get close to 5 mpg gains but after reading your replies, I am seriously doubting that now. I guess I should have gotten the 4.8 instead. Oh well, I will make the best of it. Thanks.

[69gmcc10]

is your truck 2dw or 4wd? What size tires? what gear ratio is in the diffs? When is the last time you cleaned or replaced the MAF sensor? when did you last service your plugs and wires? Have you ever ran SeaFoam through the intake to clean it or in the fuel tank to clean the O2 sensors? Are there any check engine lights or codes?

Your economy does seem lo, for a 5.3 you should be able to find 16 mpg in that engine somewhere. I would give it a complete tuneup/service before doing any mods. The 4.8 doesn't get any better fuel economy.

[Steve Cole]

Originally Posted by 69gmcc10

is your truck 2dw or 4wd? What size tires? what gear ratio is in the diffs? When is the last time you cleaned or replaced the MAF sensor? when did you last service your plugs and wires? Have you ever ran SeaFoam through the intake to clean it or in the fuel tank to clean the O2 sensors? Are there any check engine lights or codes?

Your economy does seem lo, for a 5.3 you should be able to find 16 mpg in that engine somewhere. I would give it a complete tuneup/service before doing any mods. The 4.8 doesn't get any better fuel economy.

Hi 69GMC, first of all, thanks for the reply. It is a 2wd, with 275/55/20 tires, I don't know the gear ratio, I haven't cleaned the MAF sensor, or changed the plugs/wires, or used sea foam. No codes. I just bought the truck, on my 2nd tank of gas. I will definitely look into cleaning the MAF sensor, just bought a set of iridium plugs and will pick up some plug wires. Truck has 127,000 on it currently. I will report my results. I need to run a few more tanks of gas to stabilize my mpg too.

[69gmcc10]

New to you, that is a completely different situation! Dealers and not know to do allot of maintenance work on vehicles they get, just slap that lipstick on the pig and get it out of there. You definitely need to do some maintenance/cleaning up on some stuff and your economy is gonna get better anyway, just from dirving it. If it was a dealer it is a good chance it just sat around for a while and that crappy fuel doesn't burn well, driving it and getting new fuel could really improve MPG. You don't know how it was taken care of by the previous owner, assume they did no maintenance and it has been sitting for 6 months just to be on the safe side. I would change the fuel filter on the frame rail, take off the throttle body and clean it up, seriously think about taking off the intake to soak it in a hot tank and clean the egr soot out of it as well as do all of the aforementioned cleaning.

think about doing an egr delete when you get your tune. 03 and up don have the system and the engines runs much cleaner!!!

[Steve Cole]

Hi, thanks for the reply, again. I bought the truck from an individual who used it as his daily driver. He sold it to get a crew cab. The truck was well taken care of, the car fax revealed the truck was regularly serviced and maintained by the dealer. I will definitely look into cleaning the items you suggested. Can you give me any details about the EGR delete? I am interested in doing this as well.

Thanks!

[GASoline71]

I think you just need to get used to it being a truck. Trucks really aren't built for gas mileage... never have been.

I have a 2006 K2500HD with a 6.0L and if I'm lucky I get around 9 to 10 MPG. When I'm towing my 5th wheel... about 6 to 8 MPG.

Only modification is a Dynomax 4" exhaust system, which I hate... It is way too loud.

Gary

[waco]

2003 Tahoe 4x4, 4.8l auto trans
Cat back & free flow intake
Added 3 mpg & a little better seat of the pants feel
Andy