Does anyone know if the Duramax engine makes better MPG than the 6.5L?

I will next week! I'll be sure and post a follow-up.

With todays technology the Duramax is getting way better fuel mileage. I have heard of guys getting 22-23mpg on highway.

While i never worried about mpgs in a big truck to the point of hand figuring out mpgs), having owed a 98 6.5 for 200k and now owning a new 07 with 11 k(kilometers) I know that the 6.5 got better fuel mileage.

i used to drive a dually with the 6.5 and a few mods and it would get 20+ on the highway all day driving 70mph. my duramax does that easy at 22-24mpg highway, but in the city i get 16-18 mpg where the 6.5 would get around 12-15mpg.

give it time. let the motor get broken in and you will get better mileage with your 07 and you can't determine that your 6.5 will get better mileage when your 07 only has 11 kilometers on it.

While i never worried about mpgs in a big truck to the point of hand figuring out mpgs), having owed a 98 6.5 for 200k and now owning a new 07 with 11 k(kilometers) I know that the 6.5 got better fuel mileage.

Depends on how you drive it. If you use the HP that the duramax makes, it will get worse milage. If you are nice to it and drive slow, it will get better.

jb

I rarely got better than 14 with my 6.5, but it had a 4:10 rear gear. All the Duramaxes have a 3.73 as far as I know. My DMax routineley gets 16 to 17. Pulling, 6.5 10-11, DMAX 12-13.

give it time. let the motor get broken in and you will get better mileage with your 07 and you can't determine that your 6.5 will get better mileage when your 07 only has 11 kilometers on it.

true!!...I maybe some of that is "enjoying" the lbz...lol...And like I tell everyone, ya never buy a 7000 pound truck for fuel mileage...lol

My 02 has 4.10 gears and I was at aprox 21 mpg on highway with the edge on 2 and with new injectors it has dropped a bit

I figure the Dmax is more efficient. I get slightly better around town mileage with the 6.5 but in a significantly lighter vehicle. On the highway I get about the same in each, again with the Dmax moving alot more mass.

my 6.5 gets 12-15, DMAX 15-16 around town, hwy gets about 3-5 more on each

Just got my 04 crew cab 4x4 dually, 3:73 gears with 78000 miles.

Ive check one tank so far with all types of driveing and got 13.7

was hopeing for more !!!!

Had 95 extended cab, 4x4, 6.5t, 4:10 gears with a Heath chip:

pretty steady 13.5mpg hwy

best in town was 15.2mpg

The thing pretty much averaged 14 for the most part. I checked it very often when I 1st got it.

I hear of guys getting 18-22 with the same 04 I got. How are they getting it??????

I hear of guys getting 18-22 with the same 04 I got. How are they getting it??????

They keep their foot off the go pedal! :D

If that was all stop and go city traffic with jack rabbit starts, not far off!
If that was a mix, it is low. Using the DIC or hand calculating. DIC is way off most of the time. Check the air filter, oil and fuel filters if they have not been changed in a while. Some just don't seem to get better mileage.

I have averaged just over 17.3 in combo driving, inlcuding some towing. i can get up to 22 on the high way with RPMS 2000 or less.