Diesel MPG

[bucket]

There's a 1996 6.5 turbo diesel for sale on a lot locally for just under $6500, wondering what the general concensus is on this particular model/engine?

I'd say it's hit or miss. I know of a couple guys that have had very good luck with them, but also a couple guys that had nothing but trouble with them. If the price is right, it's maybe worth a shot.

 

[crazy4offroad]

Yeah I've been reading about PMD failures due to heat and their location, and that relocating them can help. Once I read the price of said PMD I decided I might not want one so much afterall lol.

 

[HotRodPC]

Same motor as the 6.2 except its a little bigger bore I believe and Turbo was added. Also had injector pump issues, but I think its the same really, a 6.2 is a heap of **** if its not driven properly. You can work them hard, but you can't hotrod them or they take a dump.

 

[mamu]

if you are looking at a dmax. look for a 04.5-early 06. wich is a lly engine code. these are really good engines and will have a 5 speed allison 1000 tranny. the engine is about a 310hp from the factory and with a minor tune can average in the 17-20 mpg depending on driving habits. i own a 05 but im nowhere near stock and i get about 15-16 around town blowing smoke and playing. but i also get 18-21 on the highway when i go on trips. running a 315 tire too! the lb7 did have injector problems but bosch fixed that with a newer set of injectors. the ultimate thing is, wich do you want? the cost of a diesel is not that much higher if you do it smart. shop around for your filters and oil. and with mpg increase in the end its not that much different. but i am totally happy with the power and reliability of my diesel. wouldnt trade it for a gas burner anyday!

 

[muddyman184]

01 to 04 were LB7s 05 was LLY and 06 was LBZ then 07 to 10 were LMM 05 and 06 were one year model engines i read it in my diesel power magazine i drive my uncles 08 dmax crew cab 4x4 and it has alot of power and torque i would love to get one but when stuff breaks it gets $$$

 

[muddyman184]

oops just realized this thread was old o well

 

[bucket]

oops just realized this thread was old o well

It's never too late to add good info

 

[wildcatjason]

If I stay on the interstate with my 2500. It runs 21 mpg city is 17-18. Pulling 10000 I get 13. My suburban with the 4bt was 20 mpg city and I would estimate 25-26 highway.

 

[Christian Nelson]

From what I've heard Diesels without turbos never get ver good mileage, and diesels with EPA settings never get as good as they can, and if all else fails, get a bigger turbo.

Buddy of mine chipped his Chev 4x4 put bigger pipes on it, and upgraded his turbo, and says he gets over 30mpg highway. He uses his truck as an escort for the heavy haul semi's. It is a 6.5, 2006 or something I think.

Only trouble he had was apparently he got some bad diesel and it clogged up his filters and left him stranded once.

He put in a 100 gallon (I think) tank in the bed with a filler nozzle and pump, he said it is nice to have the same fuel the big trucks have because he can give them some because they sometimes have to take some odd routes and cannot fill up and risk running out of fuel enroute, so he is available with extra fuel reserve, and he can go get more for them.

He's been very happy with that combo. I've been told if a guy put an old 6.2 in one of our squares, and turbo'ed the snot out of it, and messed with the mechanical injectors abit, we could get similar results. Seems tempting at times.

I mean, I've never seen a 3/4 ton 4x4 get much better than 10mpg highway, and one could get this same truck and make it get around 20, that's double.. HMM. Now, $.80/gal more seems abit offputting, but at double mileage, seems good.

Now, if for example, I have a 1/2 ton, and get 12-14, and if I go with diesel I get 14-17, I see your point.

The question is, how much turbo do I need, and how much gas can I buy for the price of that turbo.. To me, if I wanted tall tires, and high gears, I'd go with diesel, but if I wanted low gears, I'd go gas.

 

[Christian Nelson]

Another consideration around here, is that where I live, the temps get LOW, and even newer diesels have trouble with gelling and stuff.. So, to me, this would be the bigger issue.

That said, I would like to some day do what another buddy's dad is doing, he's using a small 2 cylinder diesel motor from the semi's that they use to keep the heat and stuff on the trucks while parked in a little GEO metro, and is going to turbo it with water injection, etc, and is hoping to get close to 80 mpg.. Would be cool.

 

[Stroked]

My thoughts are in red:

From what I've heard Diesels without turbos never get ver good mileage, and diesels with EPA settings never get as good as they can, and if all else fails, get a bigger turbo.

Actually, non-turbo diesels get better fuel mileage. Case in point-6.2 vs. 6.5

Buddy of mine chipped his Chev 4x4 put bigger pipes on it, and upgraded his turbo, and says he gets over 30mpg highway. He uses his truck as an escort for the heavy haul semi's. It is a 6.5, 2006 or something I think.

Last year for the 6.5 in a pickup was 2000. I have a very hard time believing a Duramax gets 30 mpg. Maybe 20-22 highway if you're lucky.

Only trouble he had was apparently he got some bad diesel and it clogged up his filters and left him stranded once.

Yep, it's always good to carry an extra set of fuel filters when you drive a diesel.

He put in a 100 gallon (I think) tank in the bed with a filler nozzle and pump, he said it is nice to have the same fuel the big trucks have because he can give them some because they sometimes have to take some odd routes and cannot fill up and risk running out of fuel enroute, so he is available with extra fuel reserve, and he can go get more for them.

He's been very happy with that combo. I've been told if a guy put an old 6.2 in one of our squares, and turbo'ed the snot out of it, and messed with the mechanical injectors abit, we could get similar results. Seems tempting at times.

82-87 squares did come with the 6.2. I have one.

I mean, I've never seen a 3/4 ton 4x4 get much better than 10mpg highway, and one could get this same truck and make it get around 20, that's double.. HMM. Now, $.80/gal more seems abit offputting, but at double mileage, seems good.

Now, if for example, I have a 1/2 ton, and get 12-14, and if I go with diesel I get 14-17, I see your point.

The question is, how much turbo do I need, and how much gas can I buy for the price of that turbo.. To me, if I wanted tall tires, and high gears, I'd go with diesel, but if I wanted low gears, I'd go gas.

 

[Christian Nelson]

Hmm, everyone I've talked to says you don't get the optimum mileage/power from diesel unless you turbo. This is fleet trucking diesel mechanics, etc..

I may be wrong about him having the 6.5 but he's claiming 30 mpg, and he's not the usual braggar about this stuff. Not positive about the year of the truck either.

I know squares have diesel, mine doesn't, so I'd either need to buy one with Diesel (ideally, manual trans/high gear ratio) which may be a challenge finding exactly the combo I'd like so that was why I said it the way I did.

Muncie 4 speed without the granny low, or newer 5 speed, 6.2/6.5 with turbo, and 3.75 gears for the 5speed, 3.05 for the Muncie. 3/4 ton 4x4. If I could get that combo, I think a guy might be able to get 20 mpg. Then again, I also think it would be cool to do the same with a gas motor, and I bet a guy could get close to 15-17 from a small block chev. I am closer to the gas one, but still no 4 speed/5 speed yet.

Baby steps.

Dream truck, 1974 K5 with muncie (not the granny low muncie) , or 5speed with either 383 small block with above mentioned gearing, 4" lift with 33" tires, or same as above with 6.2 diesel.

Otherwise, work on my current truck, and little by little make it go and be close to this.

I have 400 Small block currently, with TH350, and body falling apart. Body first priority, then maybe 700R4, or Muncie, or 5 speed.

 

[Stroked]

Ok, gotcha A 6.2 with a 5-speed would be an ideal combo. I hope to one day put a NV4500 behind mine. I think you could very easily get 20 mpg if you don't run too big of a tire.

Yea, you definitely don't get much power without a turbo. The 6.2 is a turd. I suppose you might be able to get better fuel mileage out of a 6.2 with maybe a couple pounds of boost or so at cruising rpms.

 

[Christian Nelson]

I also have heard light boost on gas engines will improve them as well, though to keep from getting too lean, etc, you need EFI. Whereas, you don't seem to have to worry as much about the diesel. Water injection is also something I'd like to try some day..

 

[87sierra]

01 to 04 were LB7s 05 was LLY and 06 was LBZ then 07 to 10 were LMM 05 and 06 were one year model engines i read it in my diesel power magazine i drive my uncles 08 dmax crew cab 4x4 and it has alot of power and torque i would love to get one but when stuff breaks it gets $$$

the duramax was first introduced in 1999 and put into gm trucks starting in 01 with the lb7 300 bhp/520ftlbs until mid 04 then the lly 305bhp/605ftlbs from 04.5 to the end of 05 next was the lbz 360bhp/650ftlbs from 06-07 only available in the classisc body style then the lmm starting with 365bhp/660ftlbs in 07 and ending with 395bhp/765ftlbs in 2011 then the lml wich is similar to the lmm
from 01 to mid 05 was a 5 speed allison and in 06 to present is a 6 speed allison
gm also had an optional manual trans known as the zf6