6L, 2500HD Gas milage

Boogerman · November 14, 2004

I'm new at this, but I'm looking for some help. I currently pull my fifth wheel camper (8000 pounds) with a C1500, 5.7, 342 gears, 5speed od. Gas milage is about 17-19 on highway empty. When towing our trailer it drops to about 10.5 average. I'm planning to upgrade our truck some and am looking at a '01, 2500HD. This is 6.0, 4l80 auto tranny, 410 gears.

I understand this truck is not great on gas---I've heard 14 to 15--don't know??? What can I expect it to do towing my 8000 pound trailer?? Will it do better or worse than my old 90 1/2 ton?

Any one out there have any practical information??

mmayo · November 14, 2004

I get b/t 10-11 (city) depending on how I drive. I usually drive it really hard just cause I love my tune. One the hwy I can get a little over 12 best was 13.7 on a road trip that I didn't speed & didn't gun it.

major · November 15, 2004

For starters that is alot of weight for a half ton. If you checked it out that is probably over your rated max. Or the trailer weighs less than you thought. Do you pull mostly on flat ground? The reason your question interested me is I tow about 8500#, near what you tow. I bought my '04 HD partly because I had a 1/2 ton van that wasn't safe towing that amount of weight. You would say I live in hilly to foothill to mountain type country. The 6.0 does a great job. If I pulled for a full tank of gas it would probably get 10 or 11. The last tank was about 12 mpg and that was about 100 miles towing out of 370 miles traveled. Remember it is hilly country. I have about 800 miles now and am checking mileage without towing. If I am off it is about 1 or so mpg. So my guess is your mileage will probably be the same as you already get . It is still hard to picture 3.42 gears pulling that much weight with any pep with a 5.7. Or I bought a 6.0 with 4.10 gears for nothing.

SxViper · November 15, 2004

Got 15MPG with my Crew Cab 6.0L... On the highway. I drive mainly around town and get between 12-13...

willscary · November 15, 2004

Look for an 8600GVW 3/4 ton with 3.73 gears. I have an '03 reg cab 2wd with the 4L80 and the Eaton locking rear end. I get about 17mpg empty, which is the same or slightly better than I used to get with my '91 2500 with the 5.7 and the same gear. The 6.0 is MUCH more powerful than the 5.7 tbi was. I don't tow, but I spend a fair amount of time loaded with brick or concrete block, and I will still get about 15 mpg with 3800 lbs of payload. The 4.10 gear will give you more power and keep you higher in the power range when towing at highway speeds, but will cost you about 20% in fuel economy running empty. Just my thoughts. If you want the power...go for the 4.10 gear. If you want economy and the ability to work occasionally, look for the 8600 gvw with the 3.73 gear.

Boogerman · November 15, 2004

The rest of the story----Thanks MAJOR for your nice incite and imput. You are exactly right about about my 1/2 ton being "light" for the job. When I bought this rig I thought I was a genius (thought I had done all the homework) and the first trip was great. It went "down hill" when I started uphills. First in the Ozark mountains, then in the Smokies, then on to the Rockies. (I have had this rig across the Great Divide eleven times. but not like I first hitched it).

I should have traded trucks on the beginning, but I put in an auxiliary tranny behind my factory 5 sp od. I have 15 forward gears and three in reverse. As a result I have the power I need and any gear selection I need (great for coming down mountains--maybe more important than going up) But it is noisy!!!My wife and I have listened to this gear noise for about 85,000 miles, and I'm tired of it--wife says it doesn't bother her.

Knee problems dictate that I forsake the heavy duty clutch for an automatic tranny. (I opted for manual in the first place because of durability). I'm trying not to make another mistake if I buy another truck (it will probably be my last one).

Dry weight on my 5th wheel is 6700 (then we load it) I have weightd the total rig at 12,800 so I'm guessing 8000, but that is close. No you have not wasted money on the HD truck---though I have solved the power problem it is still to light for the work it does.

millerwd · November 15, 2004

I get 10.5 pulling a 6700# fifth. (4:10 rearend)

average hiway: 14

city average: unknown

best hiway : 19 at 53 MPH

Charlie in TX · November 15, 2004

It sounds like you do alot of towing. If that is the case I would recomend looking at a diesel. You will get the Alison, all the power you could want and milage.

Peter_C · November 16, 2004

If you check the milage differences between the 6.0L and the 8.1L you will find they are identical. I am suggesting that you look harder at the larger engine, that gets the same if not better milage towing and has much more power.

steiny93 · November 19, 2004

I have an 03 2500HD with the 6 liter.

Empty I get in the 9's while in town, 13's on the highway.

I don't tow in OD.

Towing a 12,000lb 5th wheel I get anywhere from 6's to 8's depending on the speed. (75mph on the interstate is 6mpg)

Towing a 3,000lb boat I still get 6 - 8 mpg. I think the 4.10 gears are what hurts the mileage.

In general the 4.10's and the 6 liter mean if you aren't in OD you are getting less then 10mpg.

My 2 pennies

Peter_C · November 19, 2004

YIKES! That is horrible milage. I have a Suburban (8.1L with 4:10's)which weighs more and get 10-11 in town and 13-15 open highway. Mind you I am a lead foot too, and have a Westers PCM. Towing a 4000 lb boat with trailer I get 11 consistantly. I do tow in overdrive, but do not consider a boat much of a load. I also test drove 4 trucks before deciding to stick with what I already had, just newer. The 3:73 gears did not have enough power with either motor and the 6 liter with them would barely accelerate up a hill empty.

TPB · November 19, 2004

In three years and 50,000 miles, my previous truck - a 2001 2500HD CC 4x4 6.0L, NEVER got better than 13 mpg - ever. Unloaded with a city/highway mix I averaged 11-12 mpg. When pulling my 7,500lb fifth wheel camper I consistently got 8 mpg.

motoman · November 23, 2004

I have 02 2500 HD CC 4x4 and carry a slide in camper that weighs around

2800lbs loaded with my gear. I just returned from Bishop Ca. and averaged 11.15 mpg ( no headwind) Going there into a strong wind I average 9.89

City driving I get between 11-13, and on the freeway I always get 15 unless I really have my foot into it. The best I have ever gotten was 16.66

mtnman2k1 · November 23, 2004

I've never gotten 13mpg or better. 12mpg mostly and that's empty truck, highway driving. Only mods are the vararam and corsa cat-back. I had expected 13-14 mpg driving with a light foot on the highway and having the mods for better breathability.

SS Crew · November 24, 2004

I've got the Dogtec 6.0 in my 2500 and in town get about 11.5 and on the road between 12.5 and 13. I once got 14.3 on the road - only since I got a ticket on the way to Parker Az., so I kept it between 70 & 75 on the way back. Man that was a long ride back.