Diesel vs gas......................

[blt2ski]

OK folks, there have been a few to many diesel vs gas threads that have shall we say gone to "Hell and a hand basket"! So if all of you would put in you BEST, no flaming reasons for going gas vs diesel, pro and con, I will either leave your thread, or copy and paste pertinant info to the 4 posts of pro and con of diesel or gas. This can include the GM 8.1 vs Dmax or Ford V-8/10 vs PSD etc too.

Be real and honest in you answers, not hear say, flaming etc PLEASE!

If posts are good ones, I will leave, if inflamatory or trolling in nature, they will be deleted! I will get this stick'd to the top for future parusing for those that need this type of info.

Added 6-23-04

We are getting closer to answers I am looking for etc.

Stuff like Ken's - T-Bone posts are good. There are a few others of you that have not posted, some with a 9 point question and answer type to figure out how you went with one or the other. If you are one of those, PLEASE repost in this thread. I may have to look up whom has done this and PM you, but if you think this is you, you now know what to do.

Also, for those of you with $ per gallon for either fuel right now, I would prefer to see a post with ...."in my area, diesel is typically .10 less than unleaded" then explain your numbers. As currently in the Seattle area, diesel and unleaded are any where from 2.05 -2.30 per gallon, with mid test .10 more and premium about .20 more, with equal high low splits. Two weeks ago those prices were upwards of .30 -.40 per gallon more. people were posting $ per gallon that were for me. "I wish" If someone is reading your post a year from now, they may want to know where your paying 1.65, when the price of fuel is over $3 per gallon. Let's keep prices out of it if possible.

Bert and tin tipi, got into a good discusion on the pros and cons of RPM's, drive train etc. I would prefer to NOT see the quote of the other in responding threads, maybe just write a quick wording of re tranny gearing, instead of the whole 40 words or so in that paragragh, so the repsonse is shorter if possible quicker and easier to read etc.

I have deleted some 15+/- posts, that were off topic etc. Please note, I am trying to keep this at the top, as the ONLY gas/diesel thread in this area. So if one is trying to decide, we do not have to go thru this BS any more. As such, I will be deleting ANY future posts close to resembling this type of topic. I may have to change "this" title to a better one, if one has a better sounding title, to be more positive, better claification, let me know here, or in a PM/e-mail, what ever you feel most comfortible with.

Again thank you for all of you that are keeping responses positive, etc.

Also we could use a few more positive reasons to go gas, as many can see I have both gas and diesel, both have a place! Both have positive reasons to buy that fuel, lets keep the threads etc to that purpose only!

Marty

[lacofdfireman]

I tow with a V-10 with 3.73 gears. I would trade my truck in in a second for a Diesel. I hate the V-10 but am stuck for now.

[PSDExcursion]

Once again boyz, what size "gasser" are you comparing to? I'd bet you are doing nothing but comparing small blocks and older BBs when you make statements like that.

Dodge has the most powerfull gas engine in any pickup with the 500HP 525TQ V10 in the 1/2 ton but would never put it into a 3/4 or 1 ton because it would only get about 5mpg towing a large 5th wheel TT. The most powerfull gas engine in the 2005 3/4 or heavier trucks is the 355HP 455TQ Ford 6.8 V10 but most get the 6.0 PSD to tow 5th wheel TT's for much more torque and up to 7,000 lb higher GCWR with 30% better fuel mileage. Unless you already drive a diesel you just won't get it.

[Lord-Dogbert]

I've got a 2003 GMC 2500HD with the 8.1l gas and Allison 5 speed, nothing is modified or chipped. We just went through the Cajon pass in California for the first time and had no problem passing even cars up. I ran at 60-65 the whole way and almost had to go far left to the #1 lane to pass some slow cars up. We stopped at a Flying J's near Victorville for a rest and was approached by a trucker who asked what the h@ll I had under the hood.

The trailer weighed a little under 11,000 #'s. My average economy was 7.2 mpg.

When I ordered my truck my friend at the dealer gave me the options between gas and diesel. The diesel right off the top cost an additional $5K and gas in my area is actually .20 cents cheaper on average now because of some reformulation to the diesel mixture for California. With all of this in mind and my driving/towing needs diesel would never give me an ROI within the period of time that I would keep the truck. I change trucks every three years or so when I see something new I like. For now my current truck will suffice until the 2006 quadra steer 2500HD comes out. I'll reappraise the diesel/gas issue again when I order that truck.

[justJeff]

This is actually an easy one. The only bad choice between diesel and gas is to not choose at all. Like most things in life, all we can do is whatever research we feel comfortable with, and based on our own unique circumstances, make a choice and live with it. This topic seems to create a bit of anomosity among folks. The reality is that we're talking about tow vehicles because we've chosen to join the RV community, and to spend time recreating with our friends and familes in a very healthy way. To get analysis paralysis and not make a decision for fear of making a bad choice would keep you from countless hours of enjoyment. It's like the guy that saves his whole life for the perfect fishing boat, only to die before he can afford it. The worst action is no action.

People can get really rude with each other over this, and some of it doesn't seem so good natured. I prefer diesel, but if you own a gas rig I'd rather applaud you for doing something and getting out there as opposed to berating you for making a different decision than I did. There are too many factors to consider to think we ever completely understand another persons decision about this. Would one of you diesel guys want to make a gas guy that bought a gas rig because he couldn't afford the diesel feel bad about what he bought? Would a gas guy want to make a diesel fan feel bad, not knowing that he bought the diesel because his father was a big fan of diesels and always talked them up?

We're lucky that there are so many good choices to be had with regard to a tow vehicle today. We can move loads that not long ago wouldn't have been possible except with a large commercial truck. We can travel safer and more comfortably. We're lucky that RV'ers are generally such a helpful group of folks, willing to help you out when you need a hand. Maybe the guy that held the flashlight for you at 3am while you made a repair has a different powerplant in his tow vehicle. It doesn't matter though, you're both out there for very similar reasons. It really shouldn't matter if he used synthetic oil or dead dino's, or what type of fuel he's burning, or what type or year of RV he has. I see folks all the time in rigs that cost astronomical sums of money, I don't think they're having any more fun that my family and I though. Heck, some of them are pushing 100 and probably saved for years to buy that thing, while younger folks are out doing it. Doesn't matter.

It's a shame that we all tend to impose our own views on others, and criticize others for coming to different conclusions. I don't care if you pull a hill faster than I do and suck my headlights out as you go past. Just bring me a beer when I'm at the campsite putting my headlights back in.

[MinnesotaYoung]

I tow a 24ft Jayco Talon Toy Hauler. I've made some modifications to the interior to fit 2 full size and 2 youth sized ATV's in it.
I started pulling my toy hauler with a Durango, 5.9Liter and 3.93:1 axles. It had enough power but the wheelbase made it one scary rig to drive. Because of the wheelbase, I wasn't comfortable towing over 65mph. Towing my trailer in flat Minnesota with the 5.9 Liter gas I got about 7 miles per gallon.
When I went to get a bigger truck, I really wanted the Crew Cab Chevy K2500HD with the 8.1 Liter. All I could find were the 6.0 Liter gas or the 6.6 Liter Duramax Deisels. I asked a number of different dealers why and the answer was always the same. "If you really need the power of the 8.1 Liter, then you really need the efficiency of the Duramax."
I was reluctant to get a deisel because I drive only 8 miles to work every day and I was worried about the impact that would have on the longevity of the engine. I was also worried about starting it when the thermometer hits -20 degrees F.
I was finally convinced when I learned that the Deisel engine comes standard with a 100,000 mile warranty which I'd have to pay a lot of money to get on the gas engine. I got the deisel and I love it! I've had it for two years next week and I haven't had one problem with it (I do make sure to plug it in overnight the winter).
I tow the same trailer with an extra ATV in the bed of the truck (total 5 ATV's) plus 100 gallons of water. No problem towing at over 70 mph through Mountain states. With the higher speed and the heavier load I get 12mpg. Almost double the mileage. This weekend I put on over 500 miles with just a small utility trailer (no camper). I averaged 20.7 mpg with the Deisel, I would've averaged about 16 with the Durango.

On the maiden voyage with the new duramax I left one full hour later than my father-in-law who was towing a similar load with a Dodge 5.2 Liter gas. When I passed him on the freeway he decided that deisel was the way to go. He got a Cummings by our next trip and hasn't looked back since.

[sack1]

Once again boyz, what size "gasser" are you comparing to? I'd bet you are doing nothing but comparing small blocks and older BBs when you make statements like that.

I'm not saying the 8.1 will out pull any of the diesels, it doesn't have to. I can maintain good speed up mountain passes without ringing its neck and I get only a few less mpg doing it with our load.

I have plenty of power to spare.

[PSDExcursion]

Here is a question for everyone. I don't know if this is the place for it. Has anyone gone back to gas after owning a diesel?

Rogerg

If there is one I have not seen it in this forum. I traded my 7.3 PSD for a 6.0 PSD.:B

[TEAM_LEADER]

I can pass all the gassers going through the mountains on the way to
the river and get a better spot. lol
I used to tow with a gas motor. Less stress on the diesel. My family
can also listen to the radio when climbing hills instead of high rpms, air sucking intakes and the modified exhuast rumbles.

[Rogerg]

Here is a question for everyone. I don't know if this is the place for it. Has anyone gone back to gas after owning a diesel?

Rogerg

[BertP]

Thaks for the explaination, Pete. I am going to keep an eye out for those engines now that I know that they exist.

I did not receive anything from you recently. I will send you a PM.

Bert

[Aquaduct]

I am curious, though. Why can't you inject the fuel directly into the cumbusion chamber in a gasser the way you do in a diesel? Is there a problem with the way it would burn? I seem to remember reading that detonation is basicly a really messed up flame front instead of a smooth one. Would direct injection of a gasser cause that kind of a problem?

Yes you can. It's been a while since I really paid much attention to the gas side of the world, but I think that there are at least a couple GDI (Gasoline Direct Injection) systems on the road today. I'm thinking a couple Japanese makes and a couple super-luxury European cars. In fact I was reading about some ideas of using GDI to develop a gasoline heavy truck engine for an anticipated economic shift away from diesel in the next decade and a half.

Actually, the concept was fairly sucessful in the pre-carbeuretion days (1930?). There are a couple fundamental issues with it even before you get to reliability questions.

First, a diesel has to use compression ignition due to the higher flash point of the fuel, so it's not as simple as applying diesel principles to gasoline, although there are a number of parallels.

The advantage of current homogenous port injection is primarily one of speed. When you burn the mix, you try to get the most pressure rise out of the combustion as possible. So you initiate combustion just before TDC so the fire is really burning and creating pressure to push down on the piston as it rolls past TDC. The problem is that as the piston moves down, volume is increasing lowering pressure and temperature. So it becomes a race to create as much pressure as possible before the moving piston neutralizes it. Fuel only burns as a vapor, so if it's mixed and a vapor before entering the cylinder, it burns faster than having to diffuse, vaporize and then burn like in direct injection. Faster burns mean more power, which is the inherent strong suit of gasoline spark-ignition port-injection sytems.

(NOTE: Before all the diesel fans get all grumpy, I'm not saying gassers make more power. It's an inherent advantage of the combustion cycle which can be overcome with things like turbochargers, just like fuel economy is an inherent advantage of the diesel cycle.)

Port injection also runs at stoich which makes emissions easier to manage with TWCs.

Direct injection gives finer control over the cylinder mixture so you can create rich zones around the spark plug that will let you run leaner than port injection. Something like 40:1 as opposed to 17:1 for a port system which is where you'd start to lose your ability to ignite reliably. More precise mix control also lets you run at lower rpms (ie.- 600 idle vs 750) and the cooling effect of the direct injection of fuel in the cylinder lets you run higher compression ratios without knock. All this adds up to diesel-like fuel efficiency on regular gas.

However, the same emissions problems of diesels crop up. NOx is high and there can be HC problems is the mixing isn't right. So now you're into higher injection pressures, more EGR, and the ever-challenging NOx reduction in O2 rich environments.

Like I said, I believe it's out there. I think one system is even set up to run both ways. The intake ports come into the cylinder in such a way that they can inject in the compression cycle for GDI operation and fuel economy, and then inject in the intake cycle for homogenous mix and power. Something says Isuzu or Mitsubishi. They've also got a Lean NOx Catalyst (LNC). EGR is used to control knock at the higher homogenous compression ratio. I think at some point, you also have a problem with too much EGR which then requires a high energy plasma or laser ignition system. But I don't think that's part of the systems on the road.

By the way, did you ever get the note I sent you?

[BertP]

I saw an item on the news last night that I thought was applicable to this thread.

With all of the fighting in Iraq, a US Army Abrahms tank was disabled in Baghdad. They didn't say what had happened to it, but it appeared that it had hit a mine and blew the track off. Without the track, the tank was completely immobilized. So, the Army sent a tank recovery vehicle, which is basically another Abrahms tank with the armament removed and replaced by "tow truck" type stuff, to get it back to base. A tank recovery vehicle showed up and backed up to the tank. They then attached some chains from the recovery vehicle to the disabled tank and towed it back to base. As I watched it go down the road, it occurred to me that they had a 70 ton "tow truck" towing a 70 ton tank. There was a rig with a GCVW of 280,000 lb being propelled down a Baghdad street by an engine developing less than 300 lb-ft of torque. Amazing.


Cdog - Interesting info. Do you have any idea why they are having such a hard time getting it to work?

Bert

[laudy]

While I towed with a gasser for years, I traded my gasser for a diesel. Someone in a previous post mentioned if the both a gasser and a diesel had the same horsepower the ease of pulling would be the same and understandingly so. However I have seen some gassers with greater horsepower than the diesel and could, granted, pull with ease,............. but I personally never seen any of "MY" gasser tow vehicles pull at the same miles per gallon that my diesel would pull at. All of my diesels easily got better m.p.g. than my gassers. Also while it might not mean anything to others, I personally like the fact that the diesel doesnt seem to be laboring as hard as all of my gassers did when pulling. Just my 2 cents worth. Good luck blt2ski!

[Cdog]

They still have not overcome the problems with direct injection for gas engines. MPI is what is in use today by all manufacturers and it injects into the airstream just above the intake valve. For some reason the CRI systems like the diesels use to put fuel directly into the cylinders, does not work well with gas engines. They have been unable to achieve reliable injector service. They claim 15-20% gas milage improvements with direct injection, but they have to make it work consistently first.

[BertP]

They do directly inject into the cylinder. They call it port injection. My 4.0L Jeep had six injectors, one for each cylinder. The injectors just don't inject at the top of the combustion cycle like a diesel does.

Tom

I thought that the port injection system still injected the fuel into the stream of air on its way to the cylinder before the intake valve.

Bert