Diesel Vs Gasoline II

Brutus

Diesels also have an advantage at altitudes. A gas engine loses about 10% power for every 1000 feet. The diesel doesn't start losing power until you start climbing over 10,000 feet.

The 15-16 quotes are for the 2000 V-10. From what I can tell, they're coming from people with F-250 2wd SRW, 3.73s. Not sure about bed size. I get nowhere near that figure with a 99 F-350 V-10 dually 4x4 with 4.30s. I average about 9.5 in a city/hwy combo, 11.5-12 in straight hwy and 8.5-9 hwy carrying my slide-in camper (total GVW of truck and camper is 12,000 pounds). I might be able to get 15-16 running empty.....downhill..... ..with a strong tailwind.

Rich, I lived in Simi and worked in Chatsworth in 1993 until the quake in January 94. Then I worked in the Irvine office. While in Irvine, I lived in Newport Beach for six months, Huntington Beach a few blocks from the pier (1200 PCH-Pierhouse Condos), and then Lake Forest for two years. Then I moved to Dallas. In the Dallas and Southern CA traffic, I had my 92 F-250 4x4 with a manual tranny. Like you, that experience resulted in an auto trans on this truck. Of course, I moved back to Alaska. I just laugh when people up here complain about the traffic.

scott1785

Rich,
Thanks for your answers. I am encouraged as I really do want to buy the diesel. I just don't want to be surprised with a $10k repair bill 5 years from now. BTW... I am interested to hear from people with 200k+ miles on their diesels (especially PSD) to find out if there have been any patterns of injector problems.
-Scott

gwmoore

Don't hold your breath Scott!

cheapowner

I know Diesel 101 is over, is it time for Diesel 202?
Since diesel fuel has lower octane rating, how do diesel engines withstand knocking.

powerisfun

I thought diesel fuel was higher (quite a bit higher) octane.
-powerisfun

lvstang

Dude, that's covered in "basic diesel." Just kidding. Actually when you think about it since knocking is preignition(the actual igniting of fuel without a spark)in a gasoline engine. All a diesel engine does is knock. The same thing that causes a gas engine to knock is how a diesel runs.
Since one of the factors of octane is the fuels ability to withstand igniting(the higher the octane the slower it burns, which always goes against the belief of higher octane fuel being more explosive which is not true.)I would imagine diesel would have higher octane so that compression ignition doesn't occur too soon. Does diesel fuel even have an octane rating?

lvstang

I think we all can talk till we're blue in the face(fingers?) It sounds like you really want a diesel. The Navistar has been around a lot of years with many happy owners. JUST GET WHAT YOU WANT and don't be paranoid about your choice. Just like with all the topics on Edmunds, people have had good and bad with almost every brand of vehicle available. I guess what I'm trying to say is if someone says they only got 50,000 out of any one of your concerned areas and another says they got a million you're still back to square one.
Get that diesel and go have some fun!!!!

p.s. One thing I will say is that diesel owners do seem very passionate about diesel ownership.
Take it easy

gwmoore

To continue lvstang's last point: One important thing to remember about diesel owners, they have ALL had gas engines as well diesel. If they prefer the diesel, they have a pretty thorough knowledge of the good and bad things of both gas and diesel, and must have a pretty good footing for their preference. That's where their passion comes from.

Those who criticize diesels tend to be those who have never owned one, or those who have only owned a diesel VW Rabbit, Peugot, or a 70-something Oldsmobile Cutlas. Not quite the same as a heavy duty Cummins or Powerstroke.

rrichf

Diesel fuel doesn't have an Octane rating but rather a Cetane (spelling???) rating. The numbers are much lower, like in the 30-40 range I think. I really don't understand how the number is calculated or what it really means. I can say that all of the diesel fuel that I have purchased, if the Cetane rating was important it wasn't apparent.

In the 7.3L, '92 which wasn't a turbo, there were some brands of fuel that seemed to run better. Better mileage? Couldn't notice. Smoother idle? Wasn't obvious. Typically on a warm sunny day, I'd be driving on the third or fourth tank of Flying J fuel and find myself saying, "Damn this thing is running good." Once my wife heard me say that and she observed that this was the week of the month and I didn't go up to Oakhurst this week. She said that I always say that the truck runs good after three weeks of running Flying J fuel. I dunno, it just seems to run good!

Rich

cdean

here's my injector story

i've worked for a industrial repair shop that had a fleet of 10-12 powerstrokes. all these trucks got LOTs of miles put on them, around 40-50K per year. the company owner started buying the PS around '94, and stopped buying GM's until his whole fleet was PS. He had all year models from '94-'98. around '96, those first trucks started getting up around the 120-150K range, problems started. 2, 3, or 4 injectors would go out, making the engine run so rough, it looked like it was about to break the engine mounts. EVERY SINGLE TRUCK in the fleet had same problems whenever they hit between 90K and about 150K miles. every year model. had nothing to do with fuel additives, or bad maintenance. this was a diesel repair business, i think they could maintain they're own trucks. the injectors on that model are electirc over hydraulic, and very complex mechanically. they simply failed. expensively. Now this owner loved the fords and the powerstroke. so what did he do? just trades all his trucks in before 100,000.

which is what everyone on this BB does, so I don't think you are going to find any stories of people with 200+K miles on their trucks, cuz i have yet to see ANYONE post on this BB that has driven a NEW diesel that much and kept it. everyone that post here has a 'new' (<50K miles) diesel, and is just defending their purchase.
i am about the only person who has seen the long term diesels around here. anyone else please speak up.

my experience is not only with that company. I know one other company my uncle works for in the same line of work, owns same type of trucks. had the exact same problems.

i am originally from rural texas, and i Know lots of ranchers, farmers, rodeo-ers, and the truck of choice in mid 90's for all the trailer pullers was the new powerstroke. these guys buy their trucks to work, not just to hear that clatter and look cool. which also means, they keep their trucks for a long time. these guys don't put as many miles on their trucks as the company i worked for, but as their trucks got out of warranty, probs started popping up, just as i told them. 4 or 5 year old trucks, just over a 100K.

As far as the new Powerstroke, i can't predict. its a totally new engine. its going to take some time to see if everything holds up on it. the problems with the powerstroke I speak of are characteristic of the '94-'98 year models. i hang my hat on it. i can honestly say i've seen or heard from the owner of about 60 trucks with all the same problem.

gwmoore:
I don't criticize diesels. and by the way, i've driven LOTS of diesels in my mechanic-ing days, plus, my family owned one. i just call what i've seen. I TOTALLY agree with you: if you want power--pay for the diesel, don't waste time trying to justify the cost. it trully is the best pulling platform, and will give the most comfortable driving package. personally i don't need it. and i think its a waste of money for someone who NEVER pulls a trailer to buy a diesel for the reason of gas mileage alone, especially since gasoline is only a couple of ticks behind diesels in mpg. i think it is good advice to stay away from diesel, if YOUR ONLY REASON IS MPG, because maintenance and repairs blow all numbers out of the water.

I am agreeing with you that the reason you buy a diesel should not be just for justified fuel savings.

sovercash1

I work for Detroit Diesel in N.C. We have a couple of Internationals with the 444e aka powerstroke. At about 150,000 had to change a couple of injectors. They are not rebuildable in the field, But don't tell anyone they arenot hard to change.

tracyo

You said to name one that has had a ps with more than 100k, with no injector problems. As I read rrichf, he said he has had 2 with over a quarter million miles with no injector problems. I would be curious to know how the fleet of trucks you talk about was maintained?

cdean

actually i said name someone else on the BB other than me that has seen any diesel with high miles...

i didn't see where rrichf said that, he's put some serious miles on the highway, 2 trucks combining to half a million miles, in only a couple of years!

the trucks were maintained perfectly. they were field trucks for a industrial diesel repair business. maintenance department had good, rigid scheduling for all tasks. like i said, there is no maintenance you can do to prevent the failures. they are electric over hydraulic injectors, not the easy simple mechanical ones that just had a plunger and a spring. (not that those are 'that' simple anyway..) fuel does not touch the portions that were failing.

i will qualify that i have seen 2 trucks that had high miles and no problems. but they were the vast majority.

cdean

Wait!

i did see rrichf's comment, and he said one of the truck was a '92 year model. That wasn't a powerstroke!

I specifically said '94 -'98.

the '88 thru '92 were very reliable, other than like rich said, the glow plugs. minor but annoying probs. My dad had an '88, and everytime a glow plug would go out, it would fry the whole controller!

markbuck

Cetane sorta opposite octane ratings. Higher the cetane number, the more likely (quicker) to autoignite (knock). Somebody earlier on says all diesels preignite, this is correct as the definition of preignite is combustion iniation without spark. Knock is a little more complicated, has to due with uneven flame front burning on a gas motor.

I regretted owning my '89 f-350 diesel every time it didn't start, about 10 times over it's life, mostly when being out in the boonies below 0 at high elevation. Went thru an injector pump, a glow plug controller, and around 15 glow plugs during 10 /170k years/miles of ownership. I agree with another's post that purchasing a diesel for only fuel economy is a bad choice, as I do believe the cost of owning a diesel for most folks is a breakeven proposition at best.

I would not hesitate to buy a diesel again (although I currently own a new gas silverado) IF I was in a couple of situations:
1) diesel fuel availability better than gas like south of the border, or farming, or constuction
2) towing frequently, large loads, for a substantial period of time.. like full timers.
3) Need for frequent prolonged idling running A/C or PTO....
4)living in relatively mild climates at low elevation. I currently live where the delta between daytime and nighttime temps is on the order of 50F with barametric pressures of 23-24" of mercury compared to standard atmospheric pressures of ~30" of mercury. These conditions knock the hell out of diesel ownership, unless you can regularly plug in....


As far as low rpm high horsepower (the big diesel advantage), I don't mind spinning a short stroke gas motor 1,000 to 1,500 rpm higher to acheive this horsepower. I typically run vehicles until the drivetrain and suspension and interior and .... fail, usually between 150k and 200k miles. With a few exceptions, I don't expect to have any motor problems with any vehicle's motor in this time period.

For my money, if you really want a diesel, and wanna keep it more than 125k, I'd buy the cummins.

gwmoore

That's all interesting about the injectors. My experience is with two ram/cummins ('89 and '97). The '89 had about 165,000 miles when we upgraded to the '97. NO PROBLEMS w/ENGINE. I wonder if injector problems are more of a Powerstroke thing. I'd like to hear if anyone is having the same problems with the Cummins.

cdean

the injectors are soley with the PS. the cummins and the GM both used a much simpler injector design. the PS injector is very complicated because the high pressure injection is generated directly at the injector. the PS fuel pump is a supply pump only. the Cummins and GM have a more complicated fuel pump that develops the high pressure, and the injectors only act like a valve. Cummins have a very reliable fuel pump, and haven't had any probs that i've ever heard of, although i know of a lot more PS's in service than Cummins in the circles I run in. the GM's have had a historically unreliable fuel pump from '94 to '98.

gwmoore

GM makes a diesel in pickups? (hehehe) Oh well, maybe they can get one right with the help of Isuzu. Only problem, by that time, people will have forgotten that GM makes 3/4-ton trucks since you can't get one (at least until next summer at current build rates).

I'm glad to hear that the injector problems you are talking about are with the Powerstroke. I didn't think I had ever heard of such problems with the Cummins.

brett039

I own a 99 Ram w/Cummins, Auto. I had to have an injector replaced at 4K miles. Not sure what was actually wrong with the injector, but it would make it idle rough and sometimes "surge" during idle. Problem was gone after replacing the injector. Service rep said this was the first time he's seen this problem. Luckily the warranty covered it.

All-in-all, I love the truck... except the auto trans. 4-speed autos just don't work well with diesels! Diesels need transmissions with lots of gears, spaced a little closer together, because of the diesels lower rpm red line. When (If?) Dodge replaces their current auto mated with the diesel, mine will be the first in line to be traded in!

Brett

gwmoore

Did the service department let you know how much the injector replacement would have cost if it wasn't under warranty?

I'm with you that Dodge needs to replace the Automatic, and I'm on hold for maybe a month to see if they get that Allison in the new year, but I still think the automatic in my dad's truck ('97 2500 Ram/Cummins auto) is pretty good. I understand that the engine is detuned to keep the tranny alive, showing some of the tranny's shortcommings. I agree it needs at least one more gear, especially in the 50-65 MPH range. And I have some gripes about how the tranny does a double-down shift when pulling hills (kicking the RPMs too high), but the overall ability and quality of the rig lets you overlook some small deficiencies 'cause it still blows everything else away.

tracyo

I thought I remember hearing or reading somewhere the injectors have been improved on the 2000 psd. Anyone know about this?

rrichf

To clarify, I put a quarter on two trucks, sequentially from '86 to '98. The trucks were F-250 and both diesel, neither a turbo.

I remember about 25-30 years ago having an old line diesel mechanic tell me that diesels needed tune up at about 125-150K miles. Except on a diesel you changed the injectors. I still think that using a good lubricity enhancer like the OTR truckers use increases the life of the injectors. Heck, $20 for 1300 gallons or 22K miles ain't bad insurance. It also keeps the water in the fuel dispursed. (You got to dispose of the water anyway.)

Rich

meredith

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