MPG for a 2500 Suburban?

Just to add to the record:
2003 Suburban 2500, 6.0L, 3.73 axle ratio, 4x4. Mods in sig.
12 - 14mpg highway.
10 - 12mpg mixed driving.
9 - 9.5 towing my TT

PAThwacker wrote:
2004 K2500 6.0 3.73 with built 4L80E Average 10 mpg city and towing. It has max tow rating of 7600 lbs limited by gear ratio only. Big block 4.10 subs in that generation have 10,000 pound max. 2007 on up 6500lb trailer max before the factory hitch gets ripped off, bwhahahaha

Big block, 4.10 Suburbans have a 12,000 lb tow rating.

While going through my maintenance log, I found a few more data points, often doing round trips and filling up at the same fuel station near my home.
fyi for those considering a 6.0 liter with a 3.73 rear gear ratio. Here ya go!
Las Vegas to Newport Beach
285 miles; 13.5 gallons; 21.11 mpg; CC @ 60 mph
126 miles; 6.97 gallons; 18.1 mpg
129 miles; 7.78 gallons; 16.6 mpg
156 miles; 9.3 gallons; 16.8 mpg
432miles; 22 gallons; 19.64 mpg
280 miles; 14.549 gal; 19.25 mpg
Mileage Datapoints: 5,500 Mile Rocky Mountain Tour
55 mph: 20.6 mpg
60 mph: 19.5 mpg
70 mph: 17.7 mpg

Our 2011 6.0 has never show anything over 16 just cruising.... downhill ..... with a tailwind.

At speed MPG is primarily a function of wind resistance.

I have stopped looking at fuel economy and the gas bills. I just like the truck and don't want to know.

@Pat... yes the tow rating and the hitch on the new trucks is embarrassing. But it's really nothing a good fab shop and a big check can't fix. :-)

2004 K2500 6.0 3.73 with built 4L80E Average 10 mpg city and towing. It has max tow rating of 7600 lbs limited by gear ratio only. Big block 4.10 subs in that generation have 10,000 pound max. 2007 on up 6500lb trailer max before the factory hitch gets ripped off, bwhahahaha

Koonzee wrote:
akcooper: Please note my Yukon XL has a 6.0 L engine.

2001 Yukon XL: 2500-6L-4L80E-3.73

I missed that but I still do not believe your getting 20 mpg out of it. To many folks have 6.0s and hardly see 15. So 20 no way.

akcooper: Please note my Yukon XL has a 6.0 L engine.

2001 Yukon XL: 2500-6L-4L80E-3.73

Mine is all original except for a Hypertech "econo" tuner. 3.73 gears, 4x4 etc fully loaded except for 4.10 LS axle. Best mine has ever done according to the instant economy readout is about 14mpg on a flat hwy @55mph in cool air. Usually average around 11 mpg overall and around 8mpg pulling the camper. I do have one size larger tire than stock so that does throw off the speedometer by a little. I drive like a grandmother and it still gets crappy mileage, just the nature of the beast.

BenK wrote:

PS...I've blocked that BS'er and is what that function is for...removing commentators who I just don't wish to read/hear from...

Sad, you must not of read my earlier post where I post my real world numbers. While I still don't believe it, Im glade he got 20 MPG out of a 8.1 :h

Believable and am in the hunt for the finishing details for the rebuild of my 1996 K3500 Suburban from a 4.1 diff ratio to something in the 4.88 range. Plus a GearVendors OD that will turn my 4 speed into an 8 speed

My 96 K3500 7.4L gets 10 MPG just about all the time. Pure freeway get 12.x MPG and occasionally get 15.x MPG often enough to claim it. Towing heavy is around 7-8 MPG dependent on terrain and my computer controlled right foot...

With the current 4.1's final ratio is 3.08 in OD at the axle. First is 10.17 at the axle.

With the 4.88's and with a GearVendors final ratio is 2.85 in double OD at the axle. OD & double OD are not for towing, but cruising. First will be 12.1 at the axle.

Double OD will have the big block cruising 65MPH at about 1,400-1,800 RPMs, at which my big block is at 100% torque capabilities. Haven't spent the time to do the detailed cal's yet...just than range as my guess (still noodling which tire size)

GearVendors 4L80E 4-SPEED AUTOMATIC OVERDRIVE chart

Waiting for that 'gosh darn....gotta rebuild the 7.4'....

PS...I've blocked that BS'er and is what that function is for...removing commentators who I just don't wish to read/hear from...

PPS...I keep my vehicles a long time and am happy with what I have...do NOT like spending what a replacement would cost (highest optioned Suburban at it's time and today that is in the $90K range) and the there are no +8.6K GVWR Subs...nor are the vans to my liking at this time)