Here I am

Return of the big block?

Attention: TDR Forum Junkies
To the point: Click this link and check out the Front Page News story(ies) where we are tracking the introduction of the 2025 Ram HD trucks.

Thanks, TDR Staff

6.7 Cummins Off-road use

6.7 exhaust temp concern

Status
Not open for further replies.
I just hope the price of diesel does not put us out of commission . I know it sounds crazy but 2 years ago I would have never thought diesel would be 80 cents per gallon more than gas. I don't even like to compare torque and longevity, But the fuel is forcing me to look at how the fuel prices have not stayed hand in hand with the way I thought they would always be. At one point in time diesel was much cheaper than gas. Trust me I bleed diesel. And I have some very powerful gas engines also. But my heart belongs to diesel.
 
I had temporary insanity in 2003 and sold my 2000 Dodge cummins for a GMC 2500 HD with the 8. 1 engine in her. On a good day with a tailwind it would get 11mpg. Towing 8 or 9mpg. After 2 years of never passing a gas station I came to my senses and got my 05 Dodge with the best engine in the land. I get 18- 20 mpg and 14 towing 12000 lbs. There is no way I would go back to a gasser!
 
I have v10. It gets 7mpg towing 17000lbs. ,11mpg empty. Give me a turbo,intercooler, 6 speed and free flowing dual exhaust and I bet it would hold its own against any stock diesel pickup. P. S. I drive only diesel cars. (40yrs. )and plan to buy 2009 turbo diesel. I think you guys are missing the point. Economy is only one of the many reasons for driving a diesel. By the way in the next 5 years the disparity between gas and diesel prices will disappear.



1st things 1st... . not bashing the Cummins whatsoever... I own and drive one myself and love it. I have an 01'that has been modified and I also own a 35' Winnebago MH with the 8. 1 gasser... also modified with Banks kit. RV weighs in at 20,300lbs. and i pull a car... 3800lbs. Pulling the same weight up a grade,i doubt many 5. 9's will pass me. My Cummins has been mildly massaged but the modifications include extra cooling for the mods done. So many trucks have the killer dyno readings but when hooked to a heavy load up a grade the egt's climb to extremes. No sense in having power and not being able to use it. My RV never fusses or overheats and will pull the grades very well. Downside? ... . it gets 7-8 true mpg at 60mph. Anything over that, it will drop to 6. 5mpg. My pickup pulls less weight... about 18K GCWR and gets 13 average and 18 or 19 unloaded. My point is not bash the gasser just yet. You can buy an awful lot of extra gas for what the diesel option costs. I realize people are probably steaming at this point and the next thing you will argue is that the Cummins will last for thousands of miles before rebuilding. True,but an 8. 1 or Triton V-10 or Hemi will go for 200K before rebuilding. And when its rebuild time, it will certainly cost less to do it!I bought a Banks Powerpack for my motorhome for under $3000 ... . Banks has done realworld testing on MH's and they dynoed at 290hp at the wheels. I can certainly tell you that I have much more money in the Cummins to get the 450 useable hp to the wheels. Before replying to this post with negativity... be certain to read again and maybe realize what kinda money you have in your truck before making judgement on me. I'm just making a comparison based on what I see on weekends pulling the same hills as the pickups with big 5th wheel trailers. I am indeed a diesel fan but it's hard to read posts that bash the 8. 1 as a slug and non-performer because the one in mine is as close to a diesel as you could expect!;)
 
First of all, we love our CTD Dodges. The wife's 72 c20 with a mild 454and 4. 10's got 12(hwy)empty and 11(hwy) towing/hauling 6000, but only got about 7 in town. Our stock 93 suburban 2500 4x4 w/454(&4L80E&4. 10's)got 8/13(city/hwy) empty and 9-10(hwy) towing/hauling approx 8,000 on a 1800 mile trip. On the same trip towing/hauling approx 9,000(w/poor aero) a 93 CTD W250(w/getrag&4. 10's) got 13-16. Both trucks were stock. The 454 was considerably quicker from a stop(especially climbing hills). The Cummins needed more gear choices due to it's shorter rpm range. That being said the CTD pulled hard, cruised without effort and did better at speed due to a usable overdrive. The same CTD got 18-20 mpg going back pulling the empty trailer(1000lb?). The trucks pulled about the same in the midrange. Last year made the same trip with wife's 01 which gets a steady 17. 5-18. 5(hwy)empty. Hauling/towing 13,500, without overdrive we got a whopping 7. 5-8. 5. The truck wanted to run overdrive ,but without a transmission temp guage I would not risk it. It got down and pulled well with no problems. I've never hooked a load to the 454 or Cummins they could not pull. That being said, I would not have attempted that pull with the old 454. It's a good motor, but it is not a Cummins. The limitations with CTD trucks have more to do with the rest of truck than Cummins. At the closest station to home regular is $3. 19 and diesel is $3. 98. Cummins has mileage, longevity, and torque. Big blocks have torque. For shorter hauls and lighter loads the big blocks are fine. For mileage, heavy loads and distance there is no substitute for the diesel. Why else would I be planning my crew cab repower, and considering a 4bt swap for the Ramcharger. One things for sure, if prices keep rising we diesel guys are gonna have to take another look at alternative fuels and crazy bombing.
 
This is what I intended to do. Iwanted to hear different opinions on this crazy fuel situation and see if some of you guys know that you can pull with a gasser if the fuel costs become prohibitive. I worked construction as a young man and picked up scraps and hauled them to the dump in a 1964 Ford ..... big dump truck... it had a straight six it was a manual 4 speed ... i think but it used to pull like crazy... . if you gear something properly it will pull the gates off from HE_ _ . I believe the love of diesel trucks and their popularity it a hard number for the fuel retailers to ignore and they are capitalizing on this opportunity. I have a 280 hp chevrolet crate motor. pulling a lawn trailer ... maybe 3500 lbs. I put in it ... 373 ... . and the 350 turbo hydro transmission it will out run my 6. 7 dodge from light to light with my dodge being empty. I know apples to melons comparison ... . just something for you guys to think about. Would I ever try to pull my goose w/ backhoe with the gasser ... ... If I had to I would... I sure don't want to though. Lets enjoy our diesels and hope something gives on these fuel prices ... get diesel back down below gasoline prices..... where they belong!!!!
 
I am not sure about an 8. 1, but a GM 7. 4 wont come close to out pulling a 5. 9... . Especially where my family does a ton of towing, on forest service roads... the Gasser overheats, the transmission cooks, and you have to stop and wait, go 2 miles, stop and wait... With the 5. 9 and a 6 speed man, you do what you what... And with the Smarty Jr on there EGTs are not an issue...
 
Man I'm glad some are happy with the performance of there 8. 1 engines. Mine had good power and the allison transmission was really nice. But yankin 12-15 thousand pounds behind that GMC compared to my current rig-no comparison. Flat out the Cummins will out run that 8. 1 in every way. Egt's have gone bye bye with a 450. 00 Smarty JR. I pull some pretty good grades up here in Northern Nevada and only see 1100 now on a hard trailer pull. I bought my first Dodge Cummins because my buddy who hauls generators for GE with 1 ton Dodge Cummins proved to me how they hold up. He has a early 90's 12 valve with over 900,000 miles-original engine. His 2001 just clicked over 500,000 miles and his 06 has 330,000 on her now. All those trucks see weights up to 20,000 lbs behind them. People who work there trucks for a livin have diesels and I am not going to panic over the cost of the fuel and get rid of a truck that will do what I need when I need to do it.
 
I am not sure about an 8. 1, but a GM 7. 4 wont come close to out pulling a 5. 9... . Especially where my family does a ton of towing, on forest service roads... the Gasser overheats, the transmission cooks, and you have to stop and wait, go 2 miles, stop and wait... With the 5. 9 and a 6 speed man, you do what you what... And with the Smarty Jr on there EGTs are not an issue...



I totally agree with you regarding the 7. 4... . the 8. 1 is basically a longer stroked version of the 454. The longer stroke is what gives the 8. 1 and 5. 9 Cummins the advantage. Low-end torque is what gets things rolling... The old Ford 300 inline 6 was a great motor also due its longer stroke. My point is that gasser's may end up back in our driveway's as the fuel rises. Those that use their diesels everyday as transporters and hauling extreme loads will certainly be money ahead by keeping with the diesel. Others,like myself,that only use their trucks once or twice a week to haul something heavy may choose another option as prices increase. I don't necessarily want to, but prices dictate what we all do. :mad:

And yes my previous post may have come across a bit cocky,but several times I have been able to creep up on the big 5vers on the really long grades. My father-in-law drives a diesel pusher... it's a 2000 5. 9 with the Banks Powerpack also, and it is rated 275hp. I can be right behind him and as the hill approaches he is able to maintain speed while mine downshifts to 4th. I can easily follow until the grade becomes steeper and when his starts to slow,mine is slowly catching up and ultimately able to pass with power to spare. Now,I'm no match for anything 400Hp or more as they have plenty of torque to maintain speed.

But with increasing emission regulations the diesels will endure,the mpg wars will become comparable again. The new 6. 7's owners are already reporting 8-9 towing heavy... . that's knocking on big-block territory. As the diesels get starved with emissions the gasser's are getting more refined and better mpg's will result. I know this sounds like I should belong to a Gasser Registry instead of TDR but the facts are out in front of us. MH magazine did a recent test on 2 RV's of exact size and length... the weight between the 2 differed due to powertrain differences in weight. The gasser avg. 7mpg with the 8. 1 and the diesel with the new 6. 7 got nearly 8. As tested,the diesel in front approached a 6% grade with the 8. 1 behind and 2/3rds the way up the gasser was able to pass. In terms of RV's,not pick-ups,it was stated that the cost of ownership in the long run was less with the gas model vs. the diesel.
 
A 8. 1 is still only pushing 450 ft lbs, at 3200 rpms..... I find it hard to beleive that lb for lb it can compete with 35% more tq... There is also only a 5hp difference..... Yes the 8. 1 is a good strong gasser, but it isn't a diesel... . And if you compare them at max hp rpm's the 8. 1 is 330hp and 412 ft lbs, the Cummins is 325 and 588, thats 43% more tq for the same hp... . And if you take 6. 7 numbers its 48% more tq, at 610 ft lbs... .
 
Last edited:
Actually the RV version of the 6. 7 is 350hp and over 800 torque. Maybe it is the gearing. The rear-end gearing is 4. 88 with 19. 5 wheels. In OD,I cruise at 2200rpm with convertor locked at 65mph. My best mileage is at 62mph turning slightly under 2100rpm. Unless the articles I'm reading and actual on road experience are decieving,the facts given are indeed true. The Cummins is a strong performer and most certaintly will outlast any and all gas engines,however,the newly refined big-block is a contender among lite-duty towing enthusiasts. I love my 01' and never plan to get rid of it but many folks are buying diesels for towing needs that don't actually need one. And as a side note, many owners are upgrading their trucks with chips and reflashes that give more hp and torque but are not suitable for towing due to egt spikes. It is none of my busines s what these owners do and I really don't care. All I'm saying is that I can and have been able to maintain acceptable speeds going uphill with the diesels. I'm not getting 12 or 13 mpg doing it, only 6. 5 or 7... but I don't have to mortgage my home when I take it in for service either!And please don't let the dealer find some parts that need replacing... . tack on another mortgage. A gasser costs less to maintain,end of story. Most people will trade up,whether pick-up or RV, before the gas motor wears out and long before the diesel does. I average about 12K a year on my MH so a diesel is just not right for me... . a fulltimer or retired traveler will have different views towards he gasser... and he should. It would be cost effective for them to own a diesel pusher. It is not myintention to stir the pot,I'm just saying,for the occasional traveler or heavy hauler,gas maybe the way to go. If you travel long distances on a regular basis and carry heavy loads, the diesel is better suited for you.
 
Yeah the commercial (non-dodge) ISB can be up to 350/750... buts its also only a 2600rpm motor... which actually would be fine by me.

Also most guys chip their diesels for street/track... The guys that chip for towing aren't using the big egt chips... in fact the best chip for towing is the Smarty Jr, 40 hp on timing only... and no EGT issues.

I am glad your gasser works for you, but the numbers just aren't there on a gas rig... .
 
Last edited:
I'm actually considering switching to a gasser for my next RV. Thinking about a 34M Winnebago MH with the Ford V10. Given the high price of a diesel CTD, poor mileage when not towing, and high diesel fuel cost, a gasser MH and an economy commuter/toad car (Honda Fit?) seems like a good combination for me.
 
I'm actually considering switching to a gasser for my next RV. Thinking about a 34M Winnebago MH with the Ford V10. Given the high price of a diesel CTD, poor mileage when not towing, and high diesel fuel cost, a gasser MH and an economy commuter/toad car (Honda Fit?) seems like a good combination for me.



That is a good choice... i have the 34D on the Workhorse-04model year... and have had good luck. The V-10 is a good motor and many will tell you to get a Workhorse just because the new Allison has 6 spds. The 6th spd was designed primarily for the Duramax pickup and in reality only drops rpm a small bit. The only real advantage as far as gas chassis go is that the final drive ratio was lowered to compensate for the added OD gear. The Ford and Chevy motor have been tested side by side several times and performance and economy are so close that it is virtually a choice of whether you are a Chevy or Ford man. I have had both the Workhorse-04 and Ford 00' 35'Adventurer and I like them both. Both were fitted with the aftermarket Banks Kit which helps alot. The V-10 is a revver and in order to keep in powerband,tach will see 4000 alot on hills. Put 42000miles doing just that with no problems at all. BTW,i tow a Honda CRV but I understand the 07' and later models cannot be towed 4 wheels down without mods. Not sure about Fit... never set one up yet. I am a Blue Ox Dealer and can look it up if you'd like. See you in the RV forum for that though!
 
According to several sources, including the local Honda dealer, the only 08 models that can be towed 4-down are the CRV 4WD and the Fit. I can deal with 34 MPG with the Fit. I sat in one and it wasn't all that bad, and I'm 6'2".
 
I'm actually considering switching to a gasser for my next RV. Thinking about a 34M Winnebago MH with the Ford V10. Given the high price of a diesel CTD, poor mileage when not towing, and high diesel fuel cost, a gasser MH and an economy commuter/toad car (Honda Fit?) seems like a good combination for me.







A Ford gasser? Ken, have you gone off the deep end. I had a Furd F250 with a big block gas engine, which I bought brand new. It turned out to be the worst truck and worst engine I have ever had in my life. I wouldn't own another Ford, gas or diesel, even if it was given to me.



I had a 10 1/2 foot cab-over-camper on that Ford. At 102K I had to have the engine rebuilt. I sold the camper and bought a new 29' Holiday Rambler 5th wheel. At 121K I had to have a new engine installed on the furd. At 134K I was having major engine problems. Rather than dealing with that stupid furd again, I gave the truck away. Not a penny exchanged, just gave it away and I never looked back. If it sounds like I'm bitter against furd, I am.



Years later, my wife insisted on buying a Ford Explorer because she liked the looks of the SUV. Almost the same scenario. After spending a considerable amount of money to keep it running, we sold it cheap. In 2003 we bought two Toyota cars. The difference is like night and day with normal maintenance on the Toyota's. Just say NO to Ford.
 
A Ford gasser? Ken, have you gone off the deep end. I had a Furd F250 with a big block gas engine, which I bought brand new. It turned out to be the worst truck and worst engine I have ever had in my life. I wouldn't own another Ford, gas or diesel, even if it was given to me.



I had a 10 1/2 foot cab-over-camper on that Ford. At 102K I had to have the engine rebuilt. I sold the camper and bought a new 29' Holiday Rambler 5th wheel. At 121K I had to have a new engine installed on the furd. At 134K I was having major engine problems. Rather than dealing with that stupid furd again, I gave the truck away. Not a penny exchanged, just gave it away and I never looked back. If it sounds like I'm bitter against furd, I am.



Years later, my wife insisted on buying a Ford Explorer because she liked the looks of the SUV. Almost the same scenario. After spending a considerable amount of money to keep it running, we sold it cheap. In 2003 we bought two Toyota cars. The difference is like night and day with normal maintenance on the Toyota's. Just say NO to Ford.



Grizzly,



I've read many of your threads in the RV forum and you sound like a knowledgeable and objestive person. The V-10 has been a proven performer in RV chassis... although down on power before 05'model year. The previous problems with plugs and aluminum heads have all but disappeared. Now if you are talking about the 460 V-8,that's a different story. MH chassis in the 90's with 460's never got over 6. 5mpg and I've driven several of them and can tell you they are slugs. The issues with being underpowered and poor fuel mileage were always complicated with in-tank fuel pumps that plaqued many owners to up trade when V-10 came out in 98'. Many in our RV club have the V-10 with no problems... exception maybe a little underpowered due to Ford's restrictive exhaust. That was updated in 05'. All makes have issues and once resolved,they are quite reliable. Take a look into our own 2nd Gen Dodges. Weak front-end... $1000 in upgrades,fuel delivery... $1000 or over,Unreliable trans when coupled to Cummins torque... as high as $8000 with billet hardware.

The aftermarket Bank's kits have helped with Ford's shortcomings and I have installed many with great results and pro-longed reliability. I even installed one on my 8. 1 and am pleased with the extra power and passing ability.
 
Grizzly,



I've read many of your threads in the RV forum and you sound like a knowledgeable and objestive person. The V-10 has been a proven performer in RV chassis... although down on power before 05'model year. The previous problems with plugs and aluminum heads have all but disappeared. Now if you are talking about the 460 V-8,that's a different story. MH chassis in the 90's with 460's never got over 6. 5mpg and I've driven several of them and can tell you they are slugs. The issues with being underpowered and poor fuel mileage were always complicated with in-tank fuel pumps that plaqued many owners to up trade when V-10 came out in 98'. Many in our RV club have the V-10 with no problems... exception maybe a little underpowered due to Ford's restrictive exhaust. That was updated in 05'. All makes have issues and once resolved,they are quite reliable. Take a look into our own 2nd Gen Dodges. Weak front-end... $1000 in upgrades,fuel delivery... $1000 or over,Unreliable trans when coupled to Cummins torque... as high as $8000 with billet hardware.

The aftermarket Bank's kits have helped with Ford's shortcomings and I have installed many with great results and pro-longed reliability. I even installed one on my 8. 1 and am pleased with the extra power and passing ability.







Don't mind me, I'm just a bit bitter with Ford. I'll never own another one.
 
Gas motored truck. Service life of 100K Miles.

100,000 div. by 8MPG = 12,500 gal. x $3. 25 = $40,625





CTD truck. Service life of 100K miles. (I know, I know. Bare w/ me here)

100,000 div. by 14 MPG = 7143 gal. x $3. 88 = $27,714



So, putting the difference of the diesel option in savings for 8 years (I drive about 12k a year now) at 5% blah, blah, blah... only earns you less than a $1000 interest. Sort of a no brainer, eh?



I feel so much better about the diesel option now, don't you? ;)



Hey again,

Some have said that you can buy a lot of gas for the cost of the diesel option. You really can't I'm sorry to report. Only about 2-2200 gal. Plug this into the above calcs and the diesel option still comes out ahead. Now if you trade your truck in every 3 yrs, maybe it makes sense to buy a gas rig for your next truck. Till I ran these calc, even I thought gas might be the way to go. I could be wrong though. Now, if VW or Nissan buys Chrysler Inc. it may be a moot point anyway.
 
Oh, right. I read somewhere, that Porsche is buying VW. Hmmm, Porsche buys VW who buys Cerberus(or what ever). Porsche TD in the SRT-10. That could be sweet. :) I think I read somewhere again that Porsche is coming out w/ one. TD that is
 
Status
Not open for further replies.
Back
Top