New to Diesel....Looking at a 5.9

[Tuski]

I've got my eye on a few trucks, all 5.9's and I have a question because this will be my first diesel truck. Mainly about fuel economy, how much better would it be over my 5.2L 4x4 half ton? The only thing I'm planning on doing in taking off the exhaust for a little extra sound, and better mileage (from what I hear). I have a 43 mile commute to work every day with about 40 miles all highway.

I know there are several threads about fuel economy, but I can't get a good idea of what is average for a stock truck....I've seen 10 mpg all the way to 22.

[dustin1706]

Originally Posted by Tuski

I've got my eye on a few trucks, all 5.9's and I have a question because this will be my first diesel truck. Mainly about fuel economy, how much better would it be over my 5.2L 4x4 half ton? The only thing I'm planning on doing in taking off the exhaust for a little extra sound, and better mileage (from what I hear). I have a 43 mile commute to work every day with about 40 miles all highway.

I know there are several threads about fuel economy, but I can't get a good idea of what is average for a stock truck....I've seen 10 mpg all the way to 22.

What are you getting with your 5.2?

There are many reasons for the variance in reported fuel economy. I would say the biggest factors are: size of tires and wheels, differential ratio, chips and programmers, engine modifications or problems, and driving style. Add in other minor factors like synthetic fluids, tire treads, tire inflation, weight of truck, aerodynamics(grill guards, tonneau covers, tailgates etc.), ambient temperatures, wind, road conditions, and the list goes on.

Between all of these things you can get a massive variance from 10 MPH to high 20's. Also, some people believe their overhead computer economy, which is generally wrong, and some people flat out lie to amek themselves feel better lol. My father and I both have mega cabs and both trucks got around 18 MPG stock on the highway. Both trucks got intakes, tuners, and a few other random goodies, now one truck gets around 20MPG and one gets around 23MPG on the highway. Both get around 14-16 in town.

Honestly, you won't save enough in fuel to justify buying the truck if economy is the only reason. However, if you need a truck and want a combination of economy and power, a 5.9 dodge is a good choice.

[Tuski]

Originally Posted by dustin1706

What are you getting with your 5.2?

There are many reasons for the variance in reported fuel economy. I would say the biggest factors are: size of tires and wheels, differential ratio, chips and programmers, engine modifications or problems, and driving style. Add in other minor factors like synthetic fluids, tire treads, tire inflation, weight of truck, aerodynamics(grill guards, tonneau covers, tailgates etc.), ambient temperatures, wind, road conditions, and the list goes on.

Between all of these things you can get a massive variance from 10 MPH to high 20's. Also, some people believe their overhead computer economy, which is generally wrong, and some people flat out lie to amek themselves feel better lol. My father and I both have mega cabs and both trucks got around 18 MPG stock on the highway. Both trucks got intakes, tuners, and a few other random goodies, now one truck gets around 20MPG and one gets around 23MPG on the highway. Both get around 14-16 in town.

Honestly, you won't save enough in fuel to justify buying the truck if economy is the only reason. However, if you need a truck and want a combination of economy and power, a 5.9 dodge is a good choice.

The 5.2L gets pretty bad, 14 mpg hand calculated, all highway driving. And I want to leave the truck stock, except for maybe some exhaust mods.
I don't necessarily NEED a huge truck like this, but 90% of everyone on this forum doesn't either. They have a diesel simply because they want one.

[kurtfromct]

Originally Posted by Tuski

The 5.2L gets pretty bad, 14 mpg hand calculated, all highway driving. And I want to leave the truck stock, except for maybe some exhaust mods.
I don't necessarily NEED a huge truck like this, but 90% of everyone on this forum doesn't either. They have a diesel simply because they want one.

i agree there are alot of people who dont NEED a big diesel truck, like me, but they way I looked at it id either get a diesel truck or a sports car. i figured a truck has much more use, more roomy, can get you through snow, and i feel safer in a big truck. i had a 06 duramax with EFI Live that really moved but now i have a 05 cummins with 5" straight pipe, aem intake, and silence ring out. its no rocket ship but it sounds awesome and moves good enough for me.

[Moneywoes]

All highway at 70-72 mph you'll probably get around 17-17.5 mpg. All highway at 80 mph you'll probably get 16 mpg.

These are non towing estimates

[asedillo]

My buddies 3rd gen 03 5.9 Is awsome, the early model injectors are way better then the electronic they have in the HO 5.9's, I'm totally jelous, he has 250hp sticks, twin turbos, high output fuel pump, and getting 800hp and getting over 20mpg, I've got the 04.5 HO and can't get If I'm lucky 16-17 mph, I am considering getting an early model 03 if It came with a mega-cab, and I'm not bullting

[dillonjm]

Originally Posted by asedillo

My buddies 3rd gen 03 5.9 Is awsome, the early model injectors are way better then the electronic they have in the HO 5.9's, I'm totally jelous, he has 250hp sticks, twin turbos, high output fuel pump, and getting 800hp and getting over 20mpg, I've got the 04.5 HO and can't get If I'm lucky 16-17 mph, I am considering getting an early model 03 if It came with a mega-cab, and I'm not bullting

You do realize that the 03's are a common rail setup just like yours. Yours just has a 3rd injection cycle, a diff turbo, and a cat (IIRC).