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Duramax LBZ Fuel Mileage??? MPG

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I'm thinking about selling my commuter and half ton chevy truck and just owning one vehicle: an 06 to 07 chevy duramax......

I need to know some realistic highway mpg figures (2wd or 4wd). Any input would be VERY appreciated!!!

THX

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I have a 2003 Duramax 4x4 and usually see 14mpg around town (in traffic with stoplights every quarter mile) and around 22mpg on the highway cruising at 55-60mph.

The newer trucks (LLY and LBZ) get around the same, or slightly less due to the emissions equipment. I have heard that the 08+ (LMM) gets only around 18mpg on the highway....and during the computers re-gen fuel miliage is in the single digits.

For comparison, I also have a 2001 Yukon 2wd with the 4.8L V8. That is basically similar to a half ton truck. I usually see 9mpg around town with it and 14mpg highway.

So you can see the diesel gets substantally better MPG, even considering it weighs alot more than 1/2 ton trucks.

The main key to good mpg in a diesel is keeping your speed around 60mph. The mpg's start dropping above 60 mph.

Hope this helps,

Jon

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Having the 05.5-07 LLY or LBZ truck will yield better highway mpg because of the 6th gear.

I have an 05 LLY w/ 5spd. I have a CAI, a full 4" exh, no cat and an Edge Juice w/ attitude tuner. On level 2 (tow) or 3 (drive) modes, I get about 17-19 city and 23 hwy, loaded with just the work tools. As long as I keep my foot out of it and off levels 4 & 5. I get good mpg. With a 16' heavy duty enclosed trailer loaded with bikes and gear and alot of tools. I get 19 hwy mpg cruising at 65@2000rpm. At 70mph@ 2300 is where it starts to drink. Then I get @15-16. The 6th gear will drop the rpms about 300 rpm at the same speeds. But the power is great. Just be sure to keep an extra fuel filter in the truck, change it every 5-7k miles and oil change every 5-8k. If you do get a Duramax, be sure to get on dieselplace.com.

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Thx for the replies. I'm actually looking to drive it over the road frequently at about 75 - 80 mph with no load (this is to get to work and back, AZ to Cal).

Will a 2wd get about 24 mpg doing this? Will it do it stock or do I have to buy some banks stuff???

THX

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Thx for the replies. I'm actually looking to drive it over the road frequently at about 75 - 80 mph with no load (this is to get to work and back, AZ to Cal).

Will a 2wd get about 24 mpg doing this? Will it do it stock or do I have to buy some banks stuff???

THX

If you're not going to tow, and want to consistently do 75-80, re-gear to taller gearing. The RPM's will suffer less, as will your fuel bill. If you can target around 2000-2300 rpm you'll get the best mileage.

Stock gearing on my 2001 LB7 I can get in the 22 range HWY, and 16-18 city.

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If you get the 2wd version, it may have the 4.11:1 gears. The 4wd usually have 3.73. So the 2wd, though being lighter and no front drivetrain will get worse mpg. If you can find a 2wd with 3.55 or 3.73's you'll be ok. But a diesel is like any other car/truck out there. It needs to breathe!!! A good CAI and a free flowing exh. will help. As for a tuner... screw Banks, For what you want/need, a good handheld will suffice. Go on dieselplace and check the for sale ads. That's where I got my Edge.

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Got 10mpg in an 06 3500 dually going up 15% grades towing a 35ft horse trailer last Wed. I thought that was pretty impressive since it didn't struggle at all and we were doing about 75mph where a gasser would have been a PITA

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I have an 06 4x4 Duramax with an LLY and I'm currently reading an average 11.9-12.1 MPG right now. Soon to rip the BS emission crap out and chip it.

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I honestly think you will have a hard time getting a consistent 22mpg. A 2wd with EFI Live tuning would be your best bet. Most duramax's have 3.73's in them, I haven't seen any with 3.55 but that would help you out. Stock expect 15-18 with good driving. A good custom tune though will bump that quite a bit. Good luck, they are great trucks.

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Will a 2wd get about 24 mpg doing this? Will it do it stock or do I have to buy some banks stuff???

THX

Doubtful.... I have never heard of a D/A, 2 or 4x4 getting anywhere close to that mileage.. and def. not going 75+. Most D/A owners say mileage goes downhill more and more, the faster above 65 mph you go.

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Thx for the replies. I'm actually looking to drive it over the road frequently at about 75 - 80 mph with no load (this is to get to work and back, AZ to Cal).

Will a 2wd get about 24 mpg doing this? Will it do it stock or do I have to buy some banks stuff???

THX

Depends on the configuration. maybe a 2wd single cab. If you're thinking about a crew cab....nope. There's not a 3/4 ton Crew cab that will get 24 mpg @75-80mph.

You can get that mileage unloaded under 70mph with a 2wd.

I have an '06 LBZ 4WD Crew cab that 16mpg as a grocery getter around town and 19-20 fully loaded on long highway road trips. The road trip mileage unloaded is about 21mpg. This is hand calculated over the last 4 years and it has Edge Juice with Attitude.

In my opinion and experience on the diesel forums, you're going to be hard pressed getting 24mpg at 75-80 in any diesel truck.

Having said that, it's a small premium to pay. once you go to the diesel, you'll never go back.

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Depends on the configuration. maybe a 2wd single cab. If you're thinking about a crew cab....nope. There's not a 3/4 ton Crew cab that will get 24 mpg @75-80mph.

You can get that mileage unloaded under 70mph with a 2wd.

I have an '06 LBZ 4WD Crew cab that 16mpg as a grocery getter around town and 19-20 fully loaded on long highway road trips. The road trip mileage unloaded is about 21mpg. This is hand calculated over the last 4 years and it has Edge Juice with Attitude.

In my opinion and experience on the diesel forums, you're going to be hard pressed getting 24mpg at 75-80 in any diesel truck.

Having said that, it's a small premium to pay. once you go to the diesel, you'll never go back.

it never gets cold where you live tho, come up here and try to start your diesel when its -40 then add the wind:p....but i agree diesels are are better expect for when its really friggen cold out

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I have never owned a Duramax. But, I have never known anyone whose computer was accurate as compared to "hand calculated" mileage.

My Cummins for example, said 25.4mpg on a 250 mile highway trip. Hand calculated was 18.5mpg. That's still not bad for a 7200#, 4x4, that will tow a small house.

Be sure to factor in all the costs of owning a diesel BEFORE you buy one. My cummins holds 3 gallons of oil, has "E" rated tires, requires a new fuel filter with every oil change ($25), and was an extra $6K over a gas truck. If you tow a lot then diesels are the way to go. But, owning a diesel as a daily driver is like owning a 2010 CRF450R to go trail riding with your 7 year old.

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... But, owning a diesel as a daily driver is like owning a 2010 CRF450R to go trail riding with your 7 year old.

with the son riding a CRF50.. ROFL

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I have never owned a Duramax. But, I have never known anyone whose computer was accurate as compared to "hand calculated" mileage.

My Cummins for example, said 25.4mpg on a 250 mile highway trip. Hand calculated was 18.5mpg. That's still not bad for a 7200#, 4x4, that will tow a small house.

Be sure to factor in all the costs of owning a diesel BEFORE you buy one. My cummins holds 3 gallons of oil, has "E" rated tires, requires a new fuel filter with every oil change ($25), and was an extra $6K over a gas truck. If you tow a lot then diesels are the way to go. But, owning a diesel as a daily driver is like owning a 2010 CRF450R to go trail riding with your 7 year old.

KTM Rookie hits it on the head here. There's a ton of guys on the forums that claim 26mpg! then you find out they have all sorts of programmers that completely screw with the fuel usage calculations for the computer. There's also a grip of people that don't even know how to hand calculate fuel usage. Once you dig a little you see how screwy their math is. One guy took his tank size and assumed that he filled it 26gal every time. One girl assumed that 1/2 on the gauge was 1/2 of her tank. If you're anal like me, you have to fill the tank to the same spot in the filler neck to be totally accurate. Not when it clicks off, because that's different each time depending on how much it foams. You can sometimes add 3 more gal. from when it clicks off.

I have an 07 CCSB 4x4 LBZ stock except 265 tires (245 stock).

it's my "do all" rig. I drive 15miles/day commuting, it hauls bikes for weekend trips and a 24' travel trailer for overnighters. I also drive like a grandpa.

I do all excel sheet calculations (totally anal about it)

I get 14.2 total average

Best tank was 18.36 all freeway 70-75mph.

worst was 12.15 towing a 6x12 enclosed 65-70mph.

My DIC (the computer) is consistiently .5-.9mpg low.

I get about 12 towing the TT, but I have only towed it 2x, so I don't have good data on it.

6th gear at 63mph is 1650rpm which is the peak of the torque curve, and from what I understand, that is your most efficient rpm. That's what I aim for, but I always rationalize out the extra $2 in fuel isn't worth the 20min. longer it will take to get there. I haven't had a chance to do a whole tank at 63mph, but I bet it would hit 20-21.

I've sat down and done calculations ad nauseum about cost analysis and even owning an eco box as a commuter and the truck as a recreational vehicle. Gas vs. Diesel. You have to look at the total cost, cost of fuel, cost of service, and initial investment. And when you look at the big picture, it's a matter of $100 more or less per month. And if you can afford a $40k rig, that shouldn't bother you.

For as little as I need the Diesel power to tow my TT, I really don't need it. I just like diesel, and I'm willing to pay for it. The same truck in a gasser would probably pencil out better (total cost).

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I have an 06 crew cab with a inch lift and 35s with the lbz

motor 373 gearing hypertech programer and a k&n. I can

average 23 at about 65 mph. Before the programer it wouldn't

see over 15 on the hiway. But I can tow my 8x14 enclosed

trailer at about 75 and still see 13-15 mpg

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I have a 06 lbz ext cab 4x4. It has a 2 inch lift and 265/70/17 tires. PPE airbox mod/4" straight pipe/egr bloked/pcv reroute/transgo jr shift kit/ppe tuner/all synthetic fluids. I get an average mix of 18mpg city/highway. At 70mph on highway mpg is 21. I normally run 82-84mph and mpg is 15-16. With the bike in the back it is about 1mpg less. All these numbers are handcalculated. The problem is when you put a tuner on the dash readout will be very high. I have had 7.3 and 6.0psd's and a 05 cummins and the dmax has gotten the best milage.

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