Diesel VS. Gas

[Metcalf]

My 300,000+ mile 7000lb brick running heavy 38.5" tires gets 17+ mpg in the city and 20+mpg on the highway, thank you Cummins.

 

[Beowulf]

Metcalf nailed it for me. It don't care about more power, longer running engines...etc. I only care about more range per tank. I want to go furhter in the bush without having to carry extra fuel.

 

[charlieaarons]

And let's not forget what this Forum is about. If you plan to leave the developed world diesel is much easier to get then high octane unleaded gasoline, but not ULSD. So one needs to de-EPA-ize a 2007 and later diesel vehicle for 3rd world use. OTOH using most modern gas vehicles in many countries will quickly ruin the engine due to massive pre-ignition.

Charlie

 

[Ozarker]

So, does this mean that the diesel willget better milage than gas in a comprable horsepower engine, pulling about the same weight, all things being equal or even similar?

 

[Metcalf]

Yes.

The main problem being that there are just not that many diesel options in the USA other than a full size truck....

 

[charlieaarons]

So, does this mean that the diesel willget better milage than gas in a comprable horsepower engine, pulling about the same weight, all things being equal or even similar?

Yes.

Charlie

 

[goin camping]

So, does this mean that the diesel willget better milage than gas in a comprable horsepower engine, pulling about the same weight, all things being equal or even similar?

Yes.

Here's an example. I have an 07 F250 PSD and tow a 6k trailer. My buddy has an 07 F250 gasser and tows a 5K trailer.

When we go places together I get 14 MPG and he gets 8-9 MPG.

He has to slow down going up hills/mountains hills and I don't.

So my friend pays $3.89 a gal and gets 9 mpg that would = .43 cents per mile

I pay $4.29 per gal and get 14 mpg and that = .30 cents per mile in fuel costs

 

[Ozarker]

Well, I like that payoff, and what about maintenance costs. I understand that a diesel lasts longer, running at lower RPM and lubricates soemwhat as it burns fuel. But injectors go bad more often (?) and parts are more? How doesthat play out?

 

[Metcalf]

My 1992 Cummins is at 300,000+ miles. The oil changes are more money since the volume of oil larger. I the 3-4 years I have owned the truck the only thing I have had to replace on the motor was a water pump ( it was leaking out of the bearing weep hole ). The water pump was only $60 or so. I have changed the fuel filter/separator a few times also.

It depends on what you have also. I think the 89-98 mechanical injected Cummins motors are just about bombproof. I have personally seen ones that went over 500,000 miles with very little maintenance other than oil changes and filters. Generally the truck will fall apart around the engine....

 

[LtFuzz]

The oil changes are more money since the volume of oil larger. ..

True, but the intervals are generally a lot longer... many would tell you changing even at every 5k miles is premature.

Friend's father has a Ford Powerstroke that went 950,000 miles before its first rebuild. Most big rig diesel motors will see, what, 1.5-2 million miles before they're totally burned out?

 

[Master-Pull]

Modding a diesel for more power is very easy, but it usually detracts from the life of the truck depending how far into it you get.

-Alex

 

[bldeagle10]

makes you wonder why they dont put the ecoboost in the raptor...

my understanding with diesels is that if driven right, and its set up how it should be, you will get better mpg and even with the higher price of fuel you will still come out on top where it counts (in the bank)

 

[goodtimes]

. . . And why do people just let them run...I understand a tractor running as I was told it takes less fuel to run it than start it, but they let some run for an hour, can't imagine that being true.

You see someguy in a large Dodge pickup and go eat lunch and let is truck run...now why would you do that and just burn up fuel? (Probably my last question about it, lol, just always wondered about that..)

I'm not sure why a guy with a diesel pickup would let it idle for an hour unless he is charging a battery, or keeping the a/c running for someone/something in the vehicle -- but it is a good idea to let the EGT drop down to the sub-350* range before shutting the engine off. This will help prevent heat-soaking the turbo bearings, which will lead to a short turbo life. This usually only takes a minute or two - far cry from an hour.

 

[Master-Pull]

Usually what we do if we have been towing hard or moving fast is just let the engine idle itself into the rest stop or area. By the time you pull off the freeway, slow down, and get yourself ready to get out of the truck and then shut it down the turbo has cooled off enough.

-Alex

 

[goin camping]

Well, I like that payoff, and what about maintenance costs. I understand that a diesel lasts longer, running at lower RPM and lubricates soemwhat as it burns fuel. But injectors go bad more often (?) and parts are more? How doesthat play out?

maintenance costs. Assuming oil change every 5k and if you went over and above the service manuel. You would still come out ahead because you'd get 300k or more out of the diesel rather than having to replace a gas engine truck at 150 to 200K miles.

*No facts to back this it's just an observation*

The guys I know with unmodded diesels seem to have little or no issues while my friends who bolt on/rechip etc. have trucks that break.