Improve Gas mileage question....

Hey guys im new to the site- just bought a 2000 Yukon Xl a few weeks ago when I was back in the states on R&R (currently deployed in afghanistan right now). Heres my question, the yukon gets real shittty gas mileage which is no suprise, but what upgrades specifically would you reccomend I do first to the vehical, and how much fuel economy would I gain?

I am considering a F&N cold air intake with a gibson cat back system....


Let Me know what you think.

Those are a couple of good mods to do to improve the enjoyment factor of driving your truck, but gas mileage will not be significantly improved. You may see a 1mpg increase, but realistically you won't see an improvement greater than that.

The best route seems to be doing the cold air intake, exhaust, etc. and then getting a Blackbear custom tune. With all those mods you could see anywhere from a 2-4 mpg increase...

Just some ballpark numbers for ya...

not having 12" wide tires and 22-28" rims is one big one that will improve MPG, especially around town.

One reason why I am looking for some takeoff GMC 20 or 18, is that I am hoping to jump up about 4 mpg around town where the oversized tires and extra weight hurt most. 12-14 city to 16.
Going from 17/24 to 11/20 is a real shocker.

Your post is pretty funny to me.

First you go out and buy a big old Clydesdale and then you complain about the feed bill.

I have talked to several 5.3 / 6.0L engine guys and their opinions are all the same. GM - in a move to squeeze as many hp out of the engine as possible, already has done what could be done to improve gas mileage.

There is two upgrade mod kits that can be done for a huge amount of money that can improve gas mileage. One is to take out the gasoline motor and put in a diesel. Most people who has done it claims that they can get about 20 miles to the gallon with the diesel engine. But you are going to spend $6000 - $12,000 depending on how much of the work you do yourself and how much you can buy used.
The second upgrade involves putting a super charger on the motor and using a set of blower pistons and rods and a camshaft upgrade. Those people claim to get 16 - 19 miles per a gallon with their upgrade.
Again, you are going to spend upwards of $6000 to install a good blower and all the hardware associated with it.

About the only cheap solution would be to get rid of as much weight inside of the vehicle and only ride around with a drivers seat and nothing else inside of the vehicle and go to a lighter set of wheels. When you reduce the amount of weight you are hauling around and you reduced the amount of rolling resistance - you will improve gas mileage. Those cold air kits and computer upgrades and cat back exhausts will only encourage you to step harder on the gas pedal and will not improve your gas mileage.
The end result is - you can't get something for nothing.

Rumor has it that the newer models gets one to two miles more per a gallon, so maybe selling what you have or trading up to something newer might be a option for you.

honestly, there isn't much you will find to see huge increases. Just too heavy of a truck with either too small of an engine, or you add a big engine and still have mileage issues.

Loose the brute and size for economy car, or pay at the pump to play.

I've got an intake and a very aggressive 91 octane tune, and I still only see 14.8 - 15.4 on average. It is what it is.

First off

An intake or drop in K&N filter may give you a 1 mpg increase or so.

Adding the oem electric fan kit (if its not an 05+) will help slighty

BB custom tune will also help.

Maybe an extra 2-4mpg total if you can keep your foot out of it after the mods

Drive sensibly and remove the roof rails and make sure your tires are inflated properly.

The Cold Air Intake and the tune help with the engine performance, but not much on the gas mileage

The e-fans will not help at all with gas mileage. They will prevent the noise when you it is really hot and the AC is on and you are starting off from a dead stop.

WoldD90 said:

The Cold Air Intake and the tune help with the engine performance, but not much on the gas mileage

The e-fans will not help at all with gas mileage. They will prevent the noise when you it is really hot and the AC is on and you are starting off from a dead stop.

Click to expand...

after my BB tune, I picked up 1-2 MPG.

Electrics fans will help a tad, less drag on the engine. You get more power, less drag, slight increase. More in power than MPG.

With the new modern electronic clutch fans, they pretty much shut off after you get the vehicle up to about 20 MPH and when it is sitting at a stop light, it really doesn't use any power at all - because at idle the engine still probably produces 100 HP if all 8 cylinders are firing on a 5.3

A drop in K&N airfilter will do nothing for the mileage, due to the fact that I was ******* several of the vehicles that I owned and none of them ever had a air filter go bad. Not even after 100,000 miles of running on dirt roads .

I would warn you against using a K&N airfilter. The people in the stock car racing world will tell you that the problem with the K&N air filter is that it is too course and let's dirt in and when the filter fails it gets holes in it and then it allows even more dirt into the engine.

Most Nascar teams will tell you that all they run on their $40,000 race engines is a WIX. Basically a 14 inch Ford Style air filter. The dirt late model engine builders will tell you that all they use is two Wix air filters, one stacked on top of the other. They use them one night and then they throw them away.

Let's say a performance air intake kit is $150 - $250

At a increase of about 1 MPG over a stock air intake and a gas mileage base line of about 15 miles per a gallon and fuel at $2.75 a gallon. You would have to drive about 20,000 miles before you even saw a profit. You are better off not buying the kit and just paying the extra $4 per a tank for the fuel.