6.0/6spd Real World Mileage

bdeboer · February 27, 2008

I have a 6.0/4spd 3.73 gear Suburban that get's 11/15 highway. Just wondering if the new 2500hd's are doing any better?

Thanks

vranasaurus · February 27, 2008

I have a 6.0/4spd 3.73 gear Suburban that get's 11/15 highway. Just wondering if the new 2500hd's are doing any better?

Thanks

I get 11-13 in the city and I haven't had it out on the highway yet. I would expect somewhere in the neighborhood of 15-16 on the highway.

Its only got 950 miles on it so far So I am hoping it get's a little better as it breaks in. But if it doesn't I won't be upset.

I don't think that there is a great increase in fuel efficiency with the 6L90E.

ATMINF · February 28, 2008

I was easily getting 17mpg on the hwy with my 2001 3/4ton burban, I thought it would be better with the new 6L90. Hopefully it will get better as the motor gets broken in.

I had said this in other threads but I currently get 12-14 city and 16-17 on the hwy with my current ride, a 2006 2wd extcab, 2500HD with the 6.0Lgasser and 4L80 trans. I was think a bunch of little things are helping me out. I got a performance tune, a bed cover, 2wd, flowmaster exhaust, homemade CAI, and full synthetic fluids all around. On my last drive during X-mas to Atlanta GA from FT Campbell, I averaged about 16.8 mpg for the trip and I was driving in the 75-85 mph range. That or I am just lucky, granted I don't drive crazy but I don't drive like a blue hair ether.

dragland · February 28, 2008

So far my CCSB Z71 w/4.10's has been at 13.5 hwy at 75 using the cruise. Only have 1500 miles on her though, so hopefully this will get better, but the pessimist in me doubts it.

2017HD · February 28, 2008

My 1yr old 2500HD with 4.10 gets 12-13 around town and 14-15 hy on cruise I also get around 10-11 towing my 24' TT that weighs in around 5600 lbs. The DIC reports 12.5 as the average MPG.

bdeboer · February 28, 2008

Thanks for the replies, my Suburban has 97K now and I am trying to decide if I want to replace it before the trade in hit at a 100K. Has anyone towed with the 3.73's that are now offered in the 2500HD? I get around 8-10mpg (depending on terrain) pulling our 29' travel trailer now, and am thinking that the 4.10's wouldn't hurt.

Edit: My tune and fresh air upgrades seemed to help the low end power more than the mileage.

ws6_guy · February 28, 2008

with the AFM, & a 6spd auto, I would imagine it would do much much better.

s-ten · February 28, 2008

with the AFM, & a 6spd auto, I would imagine it would do much much better.

The heavy-duty trucks do not get AFM, only VVT and the 6-speed tranny.

2017HD · February 29, 2008

I had the choice between the 3.73 and 4.10 and went with the 4.10. These newer engines love to rev - 3000 to 4000 RPMs and they are just hitting thier stride. Climbing 6% hills with the TT in tow in 4th gear doing 55-60 and turning around 3500 and hitting a sweet exhaust note is priceless. If I were not towing - or the fact that almost all roads to campgrounds around here have lots of grades - I would have went with the 3.73 - probably would have picked up a few more MPG when running light.