What have some of you guys done for better mileage?

[Yuke2K]

I'm new here, but thought I'd throw in my .02 from experiance with so-called "cold-air" intakes.

Most K&N FIPK systems use plastic tubing and a heat shield, but even so, you are still sucking hot air from the engine bay. Sure, some cool air will filter in from the little hole that the factory airbox used...but you have to realize that the hole was hooked up to a plastic tube running into a sealed airbox - ALL of the engine's air was being drawn from that hole. Restrictive? Yes. Coldest air possible? Yes. K&N does a decent job of compromising between the two, and they sound wicked...but I lost 3 mpg on my '99 4.3 Envoy when I installed one, and didn't feel a damn bit of extra power from that motor despite the dyno sheet included in the package.

The chromie rice pipe intakes from autozone are a joke...marketed to kids with slow fourbangers so that they can impress thier high school buddies with bling and a little extra engine sound. I bought one designed for a civic and threw it on my old '90 bonneville just to add a little sound to the engine. Didn't lose any mpg from that, but I surely didn't gain any. I'm actually suprised I didn't lose any mileage, as the intake track on the 3800s sits about 3" above the exhaust crossover pipe.

The Volant intake seems to be the best design on the market for adding power without drawing an excessive amount of hot air. They pretty much have a sealed airbox without any baffles, plastic tubing with smooth bends, and a large conical filter mounted in the box to maximize flow. They also have an extension pipe that you can mount to the bottom of the box so that you draw cold air from WAY outside of the engine bay. I'm not sure how much of a restriction that is, if any, but it sure seems like they have thier sh*t together on this subject.

I'm planning on getting a Gibson or Magnaflow catback for my Yuke before anything else, then an intake and tuner. I hope to be in the low 20mpg range when all is said and done, but we'll see.

 

[buckwheat01]

I do not know if it improved my milage at all because i have a heavy foot and get horrible mileage, but the K&N FIPK GEN2 CAI deffinately improved my acceleration. who knows how many gallons a 2001 4x4 tahoe holds? manual says 26 gallons but that cannot be right. if it is i am getting 9 MILES PER GALLON!!!!!

 

[mlepage]

OK, so am I likely to see any benefit worth the cost of a simple K&N air filter (the cloth oil-soaked kind). I already have them in my cars so if it gives any power or better mileage, I'm fine with getting one for my new 2001 Yukon SLT 5.3L. But if it's not going to do anything, or make things worse, then I won't waste the money. Verdict?

 

[Yuke2K]

My personal opinion would be to just save up and get a complete intake kit. The reusable kinds of filters are nice becasue you don't have to replace them on a regular basis, but paper filters flow just as well for the most part and last for a pretty long time. You actually risk decreasing your mileage with any kind of reusable filter, because if you over-oil the filter when you clean it, the excess will get sucked in and foul up your MAF sensor. Thats true with the full intake kits as well as the drop-in filters though (or any filter that you have to re-oil after you clean it), so if I were going to run that risk I'd just go full out and get the complete kit.

 

[diehrd]

In a way I am somewhat shocked no one has set up an intake to draw from the valance below the bumper . .

I am doing lots of mods at the moment and am going to pass on the intake mod because there is no way to off set the expense . I am more interested in getting the under hood plastic pieces painted to match truck then I am in a cold air intake .

 

[Yuke2K]

Actually I think Volant's intake kit has that option...it's an expensive add-on though. The kit itself is almost $300, then I think the bumper extension tube is another ~$150. Everyone I've talked to that uses that setup says the extension piece is worth the cost, but thats alot of change just for an intake. I'd rather put that toward an exhaust system personally.

 

[Gelly's Denali]

Hey guys,
After owning a full FIPK kit and trying to modify a stock intake, the cone filter or full kit is definitely the way to go.
Name brand aside, you can make your own bumper extension to at least assist in moving the colder air closer to the ground into the filter's area.

Using plastic vent tubing from air ducts would even work as a vessel to bring in cold air.

I saw a car show (Muscle Car) where they used aluminum tubing and ran it from the holes in the ground effects up to the airbox. They ran two tubes and connected it at the intake (via angle cut and welds) which was great, but for the reasons mentioned above (heat) our application would have to be different. The best option for us would be to run the tubing outside of the engine bay into the airbox. This should cost significantly less then $150.

Give it a try. I know I am going to.

Thanks, from the new guy, Gelly.

 

[Tree Yukon]

Good luck on the intake modes I should fill out my sig to include the 05 dodge diesel I have. It is all computerized also but I just set the timeing up by two deg manually. I don't know how the 6.0s are set up yet but I would think there's away around the computer. By the way I really don't think intakes will actuall do anything for fuel mileage. At least it never has on the 8 diesels I've had. I know totally different vehicle right. Timeing is the bigest factor in MPG. Cool are isn't going to make much difference because it will heat up from the engin before it gets used anyway

 

[jazejeff]

i have the aem brut force intake,edge performance chip,cgs cat back exhaust,BUT i have 24'' so my what ever gains i should have are offset with the wheels i get avg 14 mpg.but when i took my family to san fransico 3 weeks ago i put my factory wheel back on and got 449 miles on 1 tank of gas

 

[troyschultzvegas]

I beat the living piss out of my truck.. I think I get about 10 mpg, respectively.

 

[JKmotorsports]

I would have to agree that advancing the timing should make a definite improvement with mileage. I have yet to acquire a programmer and change some of the parameters for mine, but I am in the middle of checking the mileage gains with my exhaust and ram-air CAI setup, and so far it looks promising. The cold air intake is actually enclosed in a box and gets cooler air from OUTSIDE the truck, not from the engine bay like a lot of the aftermarket systems do. A scoop at the valance leads a 4" dia. tube up to the bottom of the airbox with an open element filter. The new intake tube is composite rather than metal, so it doesn't conduct as much heat. And the bottom is lined with a heat shield to help further minimize heating up the air in the intake tube. The intake system itself make a noticeable power and throttle response improvement.
When I go through the next tank of gas, I'll post some results.

 

[JKmotorsports]

Okay. Here are the results with the mods I talked about in the above post. With everything on the truck stock w/3.73 gears, I was getting an avg of about 14-14.5 mpg. With the addition of the 24" wheels and nothing else, I dropped to about 12.5 mpg, which was expected of course (shipping weight on these wheels were 90 lbs each!!). Now, with the intake and exhaust mods, I am back up to about 13.5-14 mpg with the same wheels. Hopefully with a custom tune, I will be able to gain another couple mpg. Hopefully.
My wife keeps trying to talk me into taking her car to work. I drive about 70 miles a day round trip for work. Her car gets about 30 mpg, so needless to say, we'd be saving a lot of gas money. But, I like my truck. She should be happy I don't drive my Z28 to work anymore. It only gets about 12 mpg.... IF I take it easy. But it's hard to stay out of the throttle, so it normally gets about 8mpg when I decide to drive it around

 

[Rafael]

Dont those larger wheels get you better mileage on the highway?

 

[JKmotorsports]

Dont those larger wheels get you better mileage on the highway?

The larger overall diameter will effectively bring the final drive ratio down, which theoretically would produce better gas mileage. But the extra weight of the wheels takes more gas to get moving, and much more braking power to stop. On the highway it may be a slight unnoticeable improvement once your moving due to the inertia of the heavier spinning wheels. But the higher amount of gas it takes to get moving is much more considerable.