Awful MPG

[DaRosa218]

Makes me want to wait until next weekend to put all of these things on just so I can throw the thing on the dyno, just to prove you wrong.

If that makes you feel better about yourself then by all means go ahead! Do a Dyno with just a Wire change with a before and after run and prove me wrong...

In my opinion if your running a stock ignition setup and stock coils your money is just being

If he was forced induction or running spray with a after-market ignition then I would say go for it, but not for a bone stock Tahoe...... It's just a waste of money!

---------- Post added at 09:14 PM ---------- Previous post was at 09:10 PM ----------

Also, this has been gone over before.

http://www.tahoeyukonforum.com/forum/showthread.php?t=14228

 

[ferr1s]

x2 on NOT changing the wires on a relatively stock motor and not getting a TB spacer. Additionally, the exhausts on these flow pretty freely unless the CAT or muffler is clogged, going to a cat back isn't going to get you 5 more miles per gallon, it will just sound better basically.

Whats the temp like where you live? These motors run better when their warmed up and the ambient temps aren't too cold. Cooler temps rob it of power and also gas mileage. I've dropped around 3 miles per gallon since the weather has been cold. As they say, 'some like it hot!'

Like some of the others have said, try some basic maintenance - Sea foam, fuel filter, Mobil 1 or the like, tire pressure, clean the MAF and TB. I definitely love my Black Bear tune. It netted me better fuel economy...when I'm not romping on the throttle because of the better performance! Best of luck.

- Ferris

 

[04SS99Denali]

mine gets 13.7 in the winter with the garbage new jersey winter gas. in the summer it will get around 14.8 - 15. the OEM gray plug wires are just as good as MSD or taylor wires there is no need to tinker with them. you can do what i listed below for around 50$ if you do it all yourself and you should see a big increase in mpg

clean your air filter or replace it
sea foam
new plugs
clean your maf and tb

 

[M3PO]

I too do not buy in to the after market wires, unless you have a hot ignition system on a hot motor. I have spent a few years at the drag strip and racing/track days on motor cycles(doesn't make a me an engine tuner so take it for what its worth), and I saw people throw thousands in to aftermarket crap and ignore the basic maintenance. Track days on a motorcycle; I always love the 260 lbs guy that would spend hundreds or thousands on billet aluminum and carbon fiber to make his bike ounces lighter, but couldn't get away from the snack-shack long enough to loose 10 lbs
Sorry got off on a tangent. But I think it this similar to the ones (not all) that will buy all kinds of mods and not perform basic maintenance.
My buddy works at a dealer and we used the 'DG' brand 'induction service', I am assuming that it is similar to sea foam, but unsure. Either way the DG service did make a noticeable difference in normal stop and go driving. The fuel mileage seems better, but it has been warmer and I know that helps a lot too.

 

[CLEAR]

I did just replace the fuel filter. I do have 20s but the MPG just doesnt seem fair. I try to drive like a grandpa.

 

[rich5368]

You do drive a 5000 lb truck. My Denali XL nets about 13 in town and the 5.3 kon I used to have got about 12. I accepted it as being a heavy ass car with a v-8 in it. You can't expect these things to get honda civic fuel mileage. It's just not going to happen.

 

[redeuce]

If you're going tp put a bunch of Sea Foam in, which is good and I did it, run Lucas fuel treatment in the next tank or 2 to relubricate everything.

 

[westcoast]

You do drive a 5000 lb truck. My Denali XL nets about 13 in town and the 5.3 kon I used to have got about 12. I accepted it as being a heavy ass car with a v-8 in it. You can't expect these things to get honda civic fuel mileage. It's just not going to happen.

hmm thats about what my denali gets and my tahoe? Why is it that my denali gets better MPG than my tahoe? I guess it could be the tune and such and the fact that its not lifted but lowered and the tahoe is lifted.

 

[rich5368]

hmm thats about what my denali gets and my tahoe? Why is it that my denali gets better MPG than my tahoe? I guess it could be the tune and such and the fact that its not lifted but lowered and the tahoe is lifted.

IDK. The only answer I could ever come up with is the 6.0 in the Denali just isn't working as hard as the 5.3 in the Yukon. It does have more torque from the bottom so doesn't require as much to get er goin. On the hwy the kon got about 17 and the Denali gets 18-20.

 

[gen3usa]

and please dont waste a dime on the TBS, these rigs gain nothing from them, if you had a throttle body injecting fuel then yes, which is when these became so popular, dont fall for the suggested gains they say you get from a TBS, you only get a neat whistle noise when you romp on it, no proven mpg gains or response.