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

[Paul_Clancy]

I understand you like the F-350. My main advice would be test drive a gm duramax/ allison truck with your wife before you buy. The gm 06 and early 07 classic trucks are best of breed. Avoid the coming ulsd trucks, lower milage, higher maintenence.
http://www.edmunds.com/insideline/do/Drives/Comparos/articleId=115662
Beyond that the diesel will be quieter than gas pulling grades because of lower rpms needed. Newer models are not always better,that depends on the brand. A dually will add stability with a camper but is a bear to park or drive downtown. I'd favor srw 1ton with firestone airbag suspension. With the tow haul mode on the allison you can pull in od and the grade braking is a feature I'm steadily amazed by (can't speak for how ford or dodge are) and would never be without.
All my opinions of course. Buy what YOU like - like what you buy.

[smercc]

My first time posting anywhere so please bear with me.
I have been reading the discussion about gas vs. diesel for TV with great interest, read about 50 pages so far. You all have provided us with a great deal of info so THANKS very much. 🙂 Also I have had a few chuckles as you all know so much more and have so much more experience then I about trucks and engines that when you all get to discussing an esoteric point I get rather lost, but it is interesting never the less. ?
Our plan is to buy a new truck within the next year. We have been saving 10 years and will sell our cherry F150 so expect to come out close to clear cash wise. We initially will have a 10ft +/- camper and tow a 10k boat. Use is only long distance, not around town. We expect to travel 20-25k miles per year for 6-8 years; mountain travel and flat land crossing the country. After a couple of years we may dump the boat and switch to a TT or 5er.
We had decided on a 2006/07 F350 AT/CC/LB/DRW/4X4 prior to reading your info but we were undecided on the engine. (The 350 may be overkill, but it is PP here, I want a BIG truck!) Although we are still not 100% sure, we are now leaning toward the diesel vs. the v10 gas. DVREDC5 had an excellent post where he compared the pros and cons of both types, that really helped.
However, after reading all of the discussion, we have a couple of unanswered questions that we hope you can help us with.
First, the low sulfur fuel problem? From what was said, I assume it is to reduce the exhaust smell/pollution? Is this going to be a disaster? Is it going to be a big problem with engine maintenance, mileages, ect? Or, is it too early to answer that question? From what someone wrote about the busses in London, maybe it will be a good thing. (My wife hates the diesel smell!)
Second, from the discussion, it seems that the three brands of trucks are approximately equivalent, however, there seemed to be a feeling that the Dodge diesel was slightly cheaper to buy & maintain but maybe not as long lasting. Since I was interested in the Ford, I was a little concerned that it might be the “dirtiest” of the four. (Post of soot on TT.) Is that correct or just maybe a poorly tuned engine? Over all, it was said many times that the choice of a truck make was more a personal preference thing and where you could cut the best dollar deal; that all makes were essentially equal. Am I about correct on that?
Third, comparing the older engines, say 2003 and before, to the 2006/07s are the newer models a definite improvement or is it all advertising hype? A couple of the things that were mentioned in posts were easier starting and no turbo cool down. Would I be better looking for a used 2003/04? Cheaper certainly!
Fourth, several folks mentioned the safety factor with a more powerful truck engine, especially descending hills. Is that due to better “engine breaking”? Is this the same for a diesel and a BB gas, say the Ford V10?
Fifth, does having DRW as opposed to SRW make any difference with either engine? How about tire size, go with the factory standard size using either engine?
Sixth, can you tow in overdrive? I know my little F150’s manual says no but many of your discussion points seemed to indicate that you tow in OD with a diesel but not with a gas due to RPM/torque. How about the BB v10 Ford, could you tow in OD?
Seventh, obviously the gas is quieter idling, however, at 60 on the highway towing, is noise really a problem inside the cab?

Any help you can provide on my interpretation of your discussions, correct or not, and our unanswered questions would be greatly appreciated. ?

[hemi-kz]

Tater Salad wrote:
But that still points to the CTD as being a "better" engine for a TV, doesn't it?

Sorry, I jumped in here late. I thought the discussion (at least on pg. 88-on) was not if but why the CTD can tow more than the hemi.
I have no problem with not having the best towing engine.
My personal situation is:
My (gas) TV tow capacity = 8750 lbs.
My camper (loaded) = 7000 lbs. max.
End of story! Lets go camping!

[BertP]

Tater Salad wrote:
Sorry, I misunderstood what you were trying to show with the example - I got it now.

No problem 🙂

Tater Salad wrote:
But I still can't grasp that Dodge would hamstring the Hemi intentionally or ingore it completely - there are some smart sumb!tches up there doing these designs (or are there? 😉 ).

This conversation has surfaced a few times over the last few years. The bottom line is we don't know. Yes, we can thow out issues of duty cycle, RE components, frames, suspension, etc, but we really don't know how a particular manufacturer comes up with that magic number. Many people have suggested that it is just a marketing ploy and nothing more.

Tater Salad wrote:
Is there maybe something that keeps them from designing a tranny that would "level the playing field" for the Hemi?

I don't know. Look at the trannies we had throughout the 70's and 80's. Not much change for 20 - 30 years except that some had an overdrive added. Look at the trannies available now. Night and day. But, as to why the manufacturers don't provide a really good tranny for the gassers, your guess is as good as mine. GM has made the Ally available for the 8.1 but I'm not sure if Ford did the same for their V10 or Dodge did with their Magnum.

Bert

[Tater_Salad]

BertP wrote:
Again, giving the CTD a tranny with a single 1:1 gear was just to show that the output numbers of an engine are not the only factors in determining the outcome of a challenge. If you want the dual to be fair, then you must allow both vehicles to optomize their configuration. If you don't the one that is optimum will win - all other things being equal.

Bert

Sorry, I misunderstood what you were trying to show with the example - I got it now.

But I still can't grasp that Dodge would hamstring the Hemi intentionally or ingore it completely - there are some smart sumb!tches up there doing these designs (or are there? 😉 ).

Is there maybe something that keeps them from designing a tranny that would "level the playing field" for the Hemi?

[Tater_Salad]

hemi-kz wrote:
Tater,
You may be on to something.
Any industrial equipment I've used (air compressors, welders, etc)has a "Duty Cycle" rating.
Maybe the CTD can put out not more max power, but max power for a longer time.

Good point. That would make sense in that Dodge would want to "derate" the Hemi because extended towing of 20K lbs would adversely affect the engine. Whereas it wouldn't for the CTD.

But that still points to the CTD as being a "better" engine for a TV, doesn't it?

[BertP]

Tater Salad wrote:
I personally believe the CTD would win. You?

I agree. As I pointed out above, the gearing favors the CTD, so it has the best chance.

BertP wrote:
Why just hamstring the CTD?

To provide an example of mismatched engine/tranny combos.

Tater Salad wrote:
What if we gave both a tranny with a 1:1 ratio?

What's the point? We already established that the Hemi would lose, so what's the point in making it lose worse?

Tater Salad wrote:
And both had either 4.10 or 3.73 REs?

Ditto

Tater Salad wrote:
Personally, I still think the CTD would win. You?

Again, giving the CTD a tranny with a single 1:1 gear was just to show that the output numbers of an engine are not the only factors in determining the outcome of a challenge. If you want the dual to be fair, then you must allow both vehicles to optomize their configuration. If you don't the one that is optimum will win - all other things being equal.

Bert

[Tater_Salad]

BertP wrote:
Sort of. What is important is that you allow the engine to develop its max power at whatever rpm that is. If we did a pull-off between two trucks - one with a CTD and the other with a Hemi - pulling a 20,000 lb trailer, which would win?

I personally believe the CTD would win. You?

BertP wrote:
What if we gave the CTD truck a tranny that had only one gear with a 1:1 ratio? There's a lot more to determining a truck's towing capability than the output of the engine.

Bert

Why just hamstring the CTD? What if we gave both a tranny with a 1:1 ratio? And both had either 4.10 or 3.73 REs?

Personally, I still think the CTD would win. You?

[BertP]

Tater Salad wrote:
The only problem with that theory is that it means if you put a 3.73 RE into the Hemi truck, the overall 1st gear ratio would be closer to the CTD's (3:1 * 3.73:1 = 11.19:1 instead of the 12.3:1). Sounds good, but Dodge rates the Hemi with 3.73:1 RE even *lower* on GCWR (down to 15000 from 17000 for the 4.10:1 RE).

But, you don't want the ratios to be the same. The Hemi develops its power at a higher rpm than the ctd so, to be fair, the Hemi need much taller gears than the CTD. Just as I pointed out. If you reduce the CTD's RE ratio to 3:1, what would happen to its tow rating? It would be lowered.

Tater Salad wrote:
I can think of a MUCH simpler answer........We've eliminated all the other variables - truck platform, transmission, rear end.....the only difference is the engine.

We haven't eliminated anything. I have shown that the gear ratios favor the CTD and that alone could account for the difference. I'm not saying it does, just that it could.

Tater Salad wrote:
Could it simply be that the CTD is a stronger towing engine than the Hemi? That doesn't mean that the Hemi is a "bad" engine for towing, just that the CTD is better at max weights........

I didn't say that it wasn't. I was just trying to answer your question about why the CTD engined truck has a higher tow rating. I can't give you a definitive answer except to say that I don't know. What did try to do though was to show that the CTD has an advantage over the Hemi because of gearing.

Tater Salad wrote:
And this isn't just a Dodge thing - GM and Ford do the same thing.....gotta be something behind it other than some conspiracy theory that the auto mfgrs are out to make the diesels look better.......

And if you look at the offerings from GM and Ford, you will find similar situations. The one exception is the tow rating GM gives its DMax powered vehicles vs their 8.1l powered vehicles. The ratings are either exactly the same or slightly in favor of the DMax in spite of the fact that the gearing favors the DMax.

Bert

[hemi-kz]

Tater,
You may be on to something.
Any industrial equipment I've used (air compressors, welders, etc)has a "Duty Cycle" rating.
Maybe the CTD can put out not more max power, but max power for a longer time.

[Tater_Salad]

hemi-kz wrote:
Anyway, my thought is the diesel is probably better at getting a load moving because its power is at an RPM that is closer to the zero RPM of the axle.
Does that make sense?

Sure, but that means that you are saying a truck with a lower HP/higher torque is a better TV than a comparably configured truck with a higher HP/lower torque.

And that is counter to the "It's the HP, stupid" theory......

[Tater_Salad]

BertP wrote:
They are not the same. Engine rpm to axle rpm:

Hemi: 3:1 * 4.1:1 = 12.3:1 overall ratio
CTD: 2.45:1 * 3.73:1 = 9.14:1 overall ratio

At max power rpm: (I believe that the Hemi develops its max power at 5000 rpm)

Hemi: 5000/12.3 = 406 axle rpm
CTD: 2900/9.14 = 317 axle rpm

That means that in first gear, the Hemi will be travelling 28% faster than the CTD if they are both at their max power point. Or, if we slow the Hemi down to the same speed as the CTD, it will be turning at just under 4000 rpm. How much power does the Hemi develop at 4000 rpm? Also, do both transmissions have the same effeciency rating at those rpm? Do the computers for either engine limit engine output in 1st gear?

You are looking for a simple answer to a complex question. The answer may be as simple as "marketing", I really don't know.

Bert

The only problem with that theory is that it means if you put a 3.73 RE into the Hemi truck, the overall 1st gear ratio would be closer to the CTD's (3:1 * 3.73:1 = 11.19:1 instead of the 12.3:1). Sounds good, but Dodge rates the Hemi with 3.73:1 RE even *lower* on GCWR (down to 15000 from 17000 for the 4.10:1 RE).

I can think of a MUCH simpler answer........We've eliminated all the other variables - truck platform, transmission, rear end.....the only difference is the engine.

Could it simply be that the CTD is a stronger towing engine than the Hemi? That doesn't mean that the Hemi is a "bad" engine for towing, just that the CTD is better at max weights........

And this isn't just a Dodge thing - GM and Ford do the same thing.....gotta be something behind it other than some conspiracy theory that the auto mfgrs are out to make the diesels look better.......

[Tater_Salad]

hemi-kz wrote:
Tater:
This has been said before: It's not only about the engine.
DC designates the strength of their transmissions in the name:
In 5-45RFE the (2nd) 5 is its rating, the trans with the CTD (48RE) is an 8.
Also (at least in 2003) the Hemi got a 10.5 inch rear and the CTD got 11.5"

I don't think it's the tranny rating either. The GVWR and GCWR are the same for the CTD with either the 6-speed manual or the 48RE and the Hemi ratings are the same with either the 6-speed manual or the 545RFE. If it were that the 545RFE was weaker, the 6-speed would give it a higher rating.

On my 2004, I believe that the 11.50 RE was an option.

[BertP]

Sort of. What is important is that you allow the engine to develop its max power at whatever rpm that is. If we did a pull-off between two trucks - one with a CTD and the other with a Hemi - pulling a 20,000 lb trailer, which would win? What if we gave the CTD truck a tranny that had only one gear with a 1:1 ratio? There's a lot more to determining a truck's towing capability than the output of the engine.

Bert

[hemi-kz]

Getting a load moving from a stop is an important part of tow capacity.
When you are starting from a stop the gear ratio math breaks down (you are dividing by zero). (of course it works in real life because of clutch or torque converter slippage)
Anyway, my thought is the diesel is probably better at getting a load moving because its power is at an RPM that is closer to the zero RPM of the axle.
Does that make sense?