Fuel mileage duramax vs. 6.0

havns3 · January 8, 2004

I also posted on another chevy forum I am trying to get as much input about this as i can so i can get a really good idea where the trucks are on mileage

I am looking at a new or used 21003 or 2004 crew cab 2500 hd but can't decide on duramax or 6.0. I want the diesel for the mileage but the 6.0's prices are a lot closer to my price range. I am looking for about 15 miles to gallon average on highway. I have a 99 crew with a 7.4 liter now so any thing over 13 is a step up. I guess my question is for the diesel and 6.0 owners, What kind of fuel mileage are you getting? Mainly for highway I drive about 600 miles a week 60 to 70 mph on highways I have heard claims that durmax gets about 18 but how does the 6.0 do?

MCourson · January 8, 2004

I dont know the numbers for the 6.0l but Im getting 21-22 mpg unloaded mixed driving, 13 mpg towing 10,000 highway at 75-80 mph.

gave20 · January 8, 2004

14 highway with the 6.0, 12-13 around town

bluenote · January 8, 2004

If you keep the speeds at 60-70 mph, you should be able to get 20 mpg running empty with a Duramax in the 2500HD. In the wintertime, you may get 1-2 mpg less because of winter blend fuel if you are in a colder climate. A cousin of mine has a 2500HD with the vortec 6000, and he doesn't get any better than he did with his previous vortec 7400.

Redapple · January 8, 2004

I keep hearing about the incredible mileage numbers, but with my 04 Duramx, the best I have gotten on Hwy was 16, best City is about 12.8. However, I have 285's on my truck, and don't know if the dealer has updated the computer with the correct tire size, and I only have 1500 miles. I hope it gets better.

Bill

MCourson · January 8, 2004

... only have 1500 miles.

Its not even near good and broken in yet.

regcab02HD · January 8, 2004

I have never gotten over 13mpg with my 6.0. The most I ever got was 12.9mpg. I usually get anywhere from 10.5-12 mpg.

bowtiebob · January 8, 2004

I have just short of 2000 miles on my 04 D/A CC SB, all stock. On my trip from Pullman to Oroville, about 250 miles, I have been getting around 21 mpg. I haven't had a true mixed tank yet, but when I'm home just making shorter trips, I'm down in the 17 range. Considering that it is pretty cool here, and that she is still real new, I am very impressed.

For the amount of driving you do, I would say the Duramax would be a wise choice. I would say between 60-70 you should see no less than 18 mpg with my experience. I know a 6.0 couldn't come close to this. Considering the added power with the diesel, I have to reccommend it.

Chevyfreek · January 8, 2004

I average between 12 & 14mpg with my 6.0L. This is from a mix of about 70% highway driving and 30% around town stop and go driving. I drive over 300mi per week just for reference. I also have a Westers tune which gave me another mpg or so depending how much I use the go pedal. The best mileage I had was on a long road trip to Atlanta from Chicago and I averaged 16mpg. The 6.0L are more economical under 65mph from my experience. It is just so hard to go that slow....

MakoMike · January 8, 2004

I keep hearing about the incredible mileage numbers, but with my 04 Duramx, the best I have gotten on Hwy was 16, best City is about 12.8. However, I have 285's on my truck, and don't know if the dealer has updated the computer with the correct tire size, and I only have 1500 miles. I hope it gets better.

Bill

BIll, you need to do your mileage and then multiply your MPG by 1.077 to get your true MPG. I moved from 245's to 285's and have done the calculations. BTW I only get 11mpg around town and 9 when towing a 6500# travel trailer.

BlackSilver · January 8, 2004

2500HD extended cab with DuraMax.

Empty mileage around 20-21, sometimes flirts with 23 since I put a bed cover on it.

Towing (about 10,000# give or take) 12-14 in flatland country of Minnesota, 10-12 in hills/mountain grades.

ToeJam · January 8, 2004

I've got the 6.0 with 9,000 miles and get an average of about 12-13 mpg. On the highway, I'll get somewhere between 15-17 depending upon conditions.

You can probably do a quick business case to see what your best option is. In rough numbers...

1) Take the cost of the D-max and divide it in half. This half you'll get back in trade-in value.

2) Take your mileage estimates for both engines and figure what your annual fuel costs will be for each power plant.

3) Add in service costs, the D-max will cost you more.

4) If the D-max is cheaper per year, then take the annual savings of the D-max over the 6.0 and divide it into the answer from #1. This will tell you how long it will take you to break even on the initial investment of the D-max. If its longer than you typically have a truck, then you're better off going with the 6.0.

..hopefully that makes sense...(cents ha ha)

autopat · January 8, 2004

I guess I have a factory fluke then, I'm getting 13-14 city, and 19-21 hwy with an '02 HD, XC, SB, 6.0, 4X4, 15K miles. It does dip significantly if my right foot gets happy.

shelbyd · January 8, 2004

1200 miles on mine so a far and no trips. Cold in Western NY. so far anywhere from 9 to 12.6. The 9 was the first few days. Couldn't help myself

QUIKSOCALHD · January 8, 2004

I have a Duramax with 35" tires and a few chips and bolt on performance parts and I am getting 16-18 hwy and 10 towing my 12k lb fifth wheel toy hauler. That is not being light on the peddle either, quick acceleration and cruising at 70-80mph.

The duramax is more $$, but way way worth it. It's not necessarily a matter of recooping the extra cost as it is convenience of getting better mileage, having way way more power than a 6.0 could ever produce and reliability for long term ownership. Diesel can go 200-300k miles, where you can't come close to that with gas.