It looks like my "new" 03 is going to be promoted to daily driver. I am expecting to sell my 4cyl work car today, trying to simplify things.

Anyway, I may have $300-$500 or so that I can invest in my truck to help out with mileage, performance etc. I am not wanting to make a dragster out of it, but if I can get some extra power for towing, and improve mileage it would be great. It is a standard cab 4.2L 4x4 manual trans, with only 26k.

My goal is to bring the mileage up some without sacrificing power. I want to get the most benefit for the least $. Any suggestions on where to start.

The only mod my truck now has is dual exhaust from the muffler back. Given the sound. I believe a less restrictive muffler was added. It also has a fiberglass bed cover.

I appreciate any suggestions.

 

Invest in a good exhaust (full system or just muffler) and get a Xcal 2 or 3 with some custom tunes from VMP Tuning. That will gives you roughly 1-2 mpg hwy, depending on how fast you drive, and how crazy you drive.

 

"gotts intake" (should work), efans, custom tune for mileage and drive with a light foot

 

Yeah, I totally forgot about e-fans. Thanks tara!

 

All good - A fresh set of O2's up front can help - If you got some miles on her.

Good rubber and a properly aligned front end is a must.

 

New O2's? Really? I got 125k on mine, but don't know if mine are still the factory O2's or not....should I look at this?

 

From what I've read, it's only worth it to replace the upstream (closest to the engine) O2's. I did mine at about 70K per Mike Troyer's recommendation when I got my XCAL2 and tunes.

 

Honestly.. Most performance upgrades only net negligibe mpg gains, if any..

It's mainly just a marketing ploy to trick us into buying their products.. mind you, they do yield small hp gains..

If you think about it.. most of the common products idividually claim 1-2 mpg gains.. if you add it all up.. it's obviously unrealistic.

Exhaust = 1-2 mpg
CAI = 1-2 mpg
Tuner = 1-2 mpg

So that's estimating about a 3-6 miles per gallon increase in fuel economy with the whole package.

I say leave it simply having the small performance gains.. if it was so easy to easily increase the fuel economy of the vehicles with cheap bolt ons, tuners, and exhausts.. I'm pretty sure the auto industry would have caught on by now.. maybe we should recommend this to MythBusters..

In my opinion.. upgrading your exhaust is actually one of the worst things you could do for your fuel economy.. especially if you have a heavy foot

 

Ever look under the hood of a an 05+ GM truck?

 

nope.. but maybe you missed the point.. I was talking about a few aftermarket parts giving significant gains over oem. I'm sure there are plenty of aftermarket companies making the same claims for 05+ GM trucks..

 

So, it seems that there is not a consensus on the value of certain mods and any particular gains.

Anyone have personal results from particular add ons or combinations?

Also, any ideas about the best place to start, if any and what should be the first priority?

What about $?

Any add ons that have hurt mileage or performance? I suppose oversized tires would hurt. Mine has the factory 16's. I wouldn't mind going up a size, but my truck is already geared a little high for my needs.

 

With that mileage - The O2's definitely, at least the forwards. However, I would do them all, - over 100,000 miles, that's the max their rated. Use Bosch only sensors.

Clean the MAF sensor as well. I would pull some general maintenance first. Use OEM components with maintenance updates. - no substitute and it should work out.

 

I think you may have misunderstood my mileage. The truck actually has 26,000 miles. So, I am starting with a practically new truck. I agree with the suggestions, but they probably do not apply here.
Any others?

 

The new GM's come from the factory with electric fans....

 

Suggestions on a brand or type? That was one of my first thoughts. I need to be careful to get something that is effective while towing a load and not overheat.