2013 Silverado 250 hd, gas mileage with 3.73 & 4.10 gears

I have the 6.0L/3.73 in SUV form. Fuel economy has improved from new to over 30k miles now. I started around 12mpg mixed the first winter, and now we average about 14mpg in mixed commuting/around town as the main family vehicle. First long trip non towing got 15mpg in the 8k mile range, and last long trip @ 20k miles was 17.7mpg. This with a Rockebox on top and a hitch carrier on back. Towing: first summer was 7-8mpg. This summer is 9-10mpg so far. 65-70mph typical tow speeds. Mine hold 5th gear until some hills when I let speed fall to about 60 before a downshift to 4th when speed climbs back up.

I really like this truck. I would order 4.10 in a heartbeat, but not available on the Burb. 6th gear, 2000rpm, at 74mph. Seems a little low. And yes, it would tow more weight/higher wind drag in 5th gear. Fuel economy will not be measurably different under the same conditions.

Keep in mind the tow ratings and GCWR. 3.73 is only about 9500 pounds. 4.10 jumps to 14k pounds, much more than the 10% gearing benefit would suggest.

The difference in the two ratios on MPG would be approximately +/- 1 MPG

2011 with 3.73...cannot get 14 mpg hiway. Best ever was 13.9

Towing 8000 pounds I average 7.3 at 65 mph. Stays in 5 th gear on level roads, but the slighest incline drops it into 4th gear at 3,000 rpms, but maintains 65 mph easily....just cannotmpass a gas station.

Thinking about a diesel.....maybe a v10 to eliminate the shifting....drives me nuts.

2011 2500hd with 3.73, towing a 7,000 lb TT. 9-11 mpg depending on hills and wind.

09 Silverado 2500hd, 6.0, 6spd, 4.10. Looking around 8-9 with 11k 5er. Will use 6th on the level with little wind.

Some folks think wt is the end all be all of towing mpg. I got 13 towing a 15K total to eastern washington with an equipment trailer and a trackhoe. Got all of 11 and drove one gear lower and about 10 mph slower up the same hills with my TT which also total was around 15K lbs. Amaxing what 25# of frontal area will do to ones fuel mileage!

Another some forget or do not know about, any additional 3# of FA is equal to adding around 1000 lbs of wt to the rig! So if you have a non slide TT, then buy a slide, that is the same wt, but it is a foot or so higher, you just in theory, added about 3K lbs to your total HP needs without adding an ounce of wt! Or about an additional 9 hp at 60 mph!

Marty

My truck in sig gets 12.5 overall 1/2 hwy and 1/2 city driving. I have gotten as high as 14 on long highway trip unloaded. I average 7 towing 12k lb fiver.

My '09 2500 4X4, 6.0 with 3:73 gets 7-8.5 towing TT that is 7,000lbs and 11' high.
Towing cargo trailer that is 9' high X 6' wide typical load is about 4000lbs and I get 13-13.5

Mine with 3.73 runs 5th gear on a level road to a slight hill with 9 ft high 8.5 wide and 7k lbs. Downshifts to 4th for a 3% grade and 3rd for a 6% grade to run 60-65 mph.

8 mpg at 65

7-8 mpg. Rear axle ratio won't make much difference. Fourth gear with one and fifth with the other on level roads, a gear lower for any hills. Had both.