average fuel economy?

[thebooger]

I looked back about 7 pages hoping to find a thread on this but I've had no luck. I recently bought a 2002 Yukon SLT 2wd with the flex fuel 5.3/4L60E. It has 137k on it and runs/drives like a new one. My wife and I have been generally babying it and the mileage hasn't been impressive. I'm a mechanic and a gear head and love GM...I'm not new to the 5.3 or to the GMT 800 platform, but this is the first Tahoe/Yukon I've ever owned. Anyhow, after driving about 500 miles mixed driving, and not really getting on it at all, the best mileage I've observed is 14.3 mpg...with the last tank being 13.2. My 04 Z71 extended cab pickup with 33's can do that. So this Yukon on stock tires should be able to crush that. It has 3.73 gears and the Grenade80 diff. Stock exhaust, doesn't miss, fresh oil change, tires inflated to 35 psi, no check engine light...ideas?

What are y'all getting with your various setups?

 

[Big Buttons]

2002 Suburban

Cam, intake, headers, ORY, exhaust, under drive pulley, stock size tires, and Blackbear tune. I get 13-14 in city and 18-19 on highway also have a 500lbs system in the hatch. I also don't go easy on her.

 

[coolchuck]

Heres a link to a previous mileage discussion...

http://www.tahoeyukonforum.com/forum/showthread.php?t=53385&highlight=miles+per+gallon

I get about 16mpg on the highway from the 6.0....still stock enginewise.

 

[ccapehartusarmyINF.(ret)]

dam i dont get much better gas mileage out of the 4.8 liter
im assuming thats probably because the 6.0 is alot newer and more fuel effiecient then my 2002 4.8

 

[YukonXL04]

Before I did any mods I was averaging 16 mpg with mostly city and stop and go highway. I haven't checked it after my mods but when I do I will update it.

 

[redemn93]

make sure its had its tune up. plugs, wires, fuel filter, clean TB and MAF etc. i dont expect itll get a whole lot better though. i found my 5.3 tahoe to get better highway mileage at 85mph. more ground covered over the different in fuel at lower mph. 3.73s also. with 32" tires and very heavy 20" wheels i got 14mpg no matter how i drove.

 

[jdpber]

Tuned. Lots of EFI tuning. But I'm 6" 35s airaide mdi tube stock box. K&N drop in (cleaned monthly) TB cleaned monthly. Flow master 40series 2.5 Y back 1 into 2. Keep the tires rotated every 2 months, air pressure level, and nitrogen filled. Also every other tank I use Lucas fuel treatment. Yup that's it simple. Also roll starts don't floor it off the line every time you stop otherwise you will get 8mpg it's logic. Getting rolling is the major of bad mpg. Also I have stock 3.73 gears.

I am tuned for 87 octane. And I consistently get 16-17 city now.

Hwy with hills (downshifting)
60-65 1800rpm hwy 19
75-80 2100-2200 hey 18

Flat hwy no down shifting
60-65 1800 21
75-80 2100-2200 18-19

65 is the magic sweet spot.

I have done multiple full tank hwy runs. And averages over 2-3 tanks same hwy setting.

 

[scoobyxj]

My avg is in the high 14s with a mix of city/hwy. I just took a trip of almost 800 miles, and got in the hi 15s. It had probably 250lbs of gear in the back, and I drove 70-80mph most of the trip (mostly around 75) in light rolling hills (western OH, and IN)... Fully stock aside for the 255/75R17 BFG MTR's (OEM Jeep Rubicon take offs...)

 

[Time2Kill]

My mom gets 16.3~16.7 on her 2005 Escalade. She drives like an old lady though. My wife gets ~12 on our 2005 Yukon Denali. Not sure why its so much lower being that its basically the same car/drivetrain. Might be time for a tune up...

 

[jdpber]

Well the 6.0 and the 5.3 get different mpg. And tune, clean air, clean TB, clean injectors make worlds of diff.

Look at me. I'm lifted on 35s and getting stock dealer spec economy now.