Free 7 Day Trial RV GPS App RV Trip Planner Campground Reviews RV Maintenance Free 7 Day Trial ×
 


Reply
 
Thread Tools Search this Thread Display Modes
 
Old 12-16-2018, 06:37 AM   #381
Rivet Master
 
2012 19' International
Southeastern MI , Michigan
Join Date: Aug 2016
Posts: 2,211
Quote:
Originally Posted by GettinAway View Post
Thatís exactly why I drive Toyotaís. Routine maintenance on all of them up to 250,000 miles. These fleets mentioned in a previous post switching to gas from diesel are doing so for a reason. More than likely itís because of overall cost.
Any good truck will go 250k easy, all of mine have gone way past that. However, routine maintenance at that point could include anything that wears out, like several sets of brake rotors, ball joints, and control arms, and hopefully itís had a couple sets of shocks by then. Suspension work ainít cheap and if those parts havenít been touched on that Toyota Iíd hate to be next to it on a freeway.
Countryboy59 is offline   Reply With Quote
Old 12-16-2018, 09:05 AM   #382
Rivet Master
 
2007 27' International CCD FB
San Diego , California
Join Date: Sep 2014
Posts: 1,769
Quote:
Originally Posted by Countryboy59 View Post
Well mine is cradled, heated and cooled also, with bluetooth and Alpine sound system and a nice Cummins rumbling under the hood. If you see it by the side of the road I’m probably putting out a fire or pulling something smaller out of a ditch. A Lexus just wouldn’t look right in that situation but they do look good at a tofu stand or nestled in a Starbucks parking lot lol. And when I visit an OEM plant mine is nicely intact when I come out.

Just kidding of course; these threads do get ridiculous but they are fun. Toyota’s been making cars forever and they know how to do it. Just not my cup of tea. They also employ lots of folks here. Too bad about that sheep head emblem on the Ram and they are making it even bigger now. I’m surprised the eyes don’t light up��
It is all in jest and my opinions are only important to me. Truck manufacturers can't build enough premium versions. I'd proudly own one (and I even prefer the Dodge's styling within the big 3).

Just goes to show, subjective points and personal needs are just as important as anything. Including drive train preference.

I'll end in saying any motor in the 400hp vicinity will make an owner happy. Regardless of gas or diesel. Pick your poison after that: efficiency, reliability, styling...
pteck is offline   Reply With Quote
Old 12-16-2018, 10:23 AM   #383
Rivet Master
 
gypsydad's Avatar

 
2017 28' Flying Cloud
2014 25' FB Flying Cloud
2008 25' Safari FB SE
Georgetown (winter)Thayne (summer) , Texas & Wyoming
Join Date: Jan 2007
Posts: 4,174
Quote:
Originally Posted by GettinAway View Post
I have just heard three more horror stories about Diesel engine failures, and the cost to repair. I think the cheapest one was $2500. These were all late model, but out of warranty repairs. I think if I owned a diesel Iíd plan on trading it in before the warranty ran out. That and the $1 per gallon penalty to drive one will keep me in a gasser. I could get one, but I just donít need one. And I donít agree with an earlier comment about diesels being safer. The only time they have an advantage is coming down a mountain pass. I canít think of another time. I just never get going that fast down the mountain to begin with. Both my brothers have 250 power strokes. Iíve always thought Iíd end up with a diesel, and liked them. My son who works with the automotive industry bought a F250 with the big gas engine. Very capable truck. And comfortable.
Not sure anyone is saying a diesel is safer....but, to your point about coming down a mountain pass...Sure you can pull an AS with just about any TV and if your happy, that's great!

But, as I said earlier, if you are pulling a bigger, heavier AS up/down/around in the Rockies or some mountainous area, like many of us do, the bigger TV 3/4 and 1T with diesel engine, offer obvious advantages. Not saying you can't get it done with a gasser....just saying, if you have not towed in these types of conditions with a newer diesel TV you may never understand what we are talking about.
__________________
Empty Nesters; Gypsies on the road!
2017 28' Twin Flying Cloud
2017 F250 King Ranch, 4X4, 6.7L, Blue-Ox WDH
Summer-Star Valley Ranch RV Resort (Thayne, WY); Winter-Sun City (Georgetown,TX)
gypsydad is offline   Reply With Quote
Old 12-16-2018, 11:33 AM   #384
4 Rivet Member
 
mkcurtiss's Avatar
 
1968 26' Overlander
CORDOVA , TN
Join Date: Apr 2018
Posts: 373
Images: 4
Quote:
Originally Posted by overlander64 View Post
Greetings Hempel!




Sadly, yes, I have had experience towing with a 2017 Nissan Titan XD Diesel. Had high hopes for the truck but they have been dashed. Fuel efficiency is deplorable -- my K2500 GMC Suburban with 454 cubic inch V8 did better in both solo and towing fuel economy and was still dependable after 20 years and nearly 200,000 miles. The two Nissan dealers that are within 40 miles of my home are indifferent toward their diesel trucks and have provided less than stellar support (I am accustomed to excellent support from my GM dealer of more than 30 years). The truck has yet to pass 6,000 miles as it needs to go to the dealer at least once every other week for one problem or another -- from three total losses of brakes, four partial loss of brakes, a built-in trailer brake controller that randomly locks up the trailer brakes, an engine that goes into "limp-home" mode for no known reason as well as heat and air conditioning systems that tend to develop a mind of their own -- and driver's side exterior handles that have failed as well as the interior driver's interior door handle. In additional to mechanical issues that truck had defective paint from the factory and a damaged bed liner at delivery.


We have only been able to tow about 500 miles with the truck at this point, and that was not a pleasant experience as the trailer brakes had to be disabled after the first 25 miles due to the controller's lockup problem. It seems that these trucks are either exceptionally good or exceptionally bad with little in-between.


I always try to be positive, but I can't find much to be positive about when it comes to this truck.


Kevin

Holy Cow! You are referring to the Nissan Titan Diesel, correct?
__________________
1968 Overlander Land Yacht International
Ford E-350 W V-10 booom!
2018 Chevy Tahoe smooooooth
Find a way to enjoy life and have fun, every day !
mkcurtiss is offline   Reply With Quote
Old 12-16-2018, 01:15 PM   #385
Rivet Master
 
TouringDan's Avatar
 
1966 24' Tradewind
1995 34' Excella
Lynchburg , Virginia
Join Date: Jun 2006
Posts: 3,989
Quote:
Originally Posted by Isuzusweet View Post
As a huge diesel fan I agree with everything you stated.

Yes, in the old days, diesels were very simple engines and had major advantages over their gas brethren; from mpg, longevity, reliability, simplicity, ease of maintenance, and fuel expense. All that has changed and none for the better.

You want (NEED) to trade in a new modern diesel before the warranty is up.......$1,200 to $2,000 PER fuel injector, plus installation, multi thousands for high pressure fuel pumps, EGR system maintenance........the sensors; labour to diagnose and repair are leading to multi thousand dollar repair bills.

The only advantage, as you stated was if the diesel was equipped with an engine brake.....nice to have, but not neccessary for 99.99% of the time you have the truck. In fact, I'd loath to use it, just in case it fuffed up my engine.....brake pads are cheaper to buy by far, and diesel trucks and gasser trucks typically have the same brakes.

Your son was smart to buy a gasser and he's not the only one, as even big cooperations that typically bought 3/4 diesels are switching to gas models. Hydro One in Ontario hasn't bought a diesel 3/4 ton off Ford for years now; gassers are cheaper to buy and maintain.

Cheers
Sidekick Tony

PS I'm still putting my 1993 Cummins 12 valve into my Argosy, but praying diesel drops in price?


I believe this is the most helpful and informative post in answering the question of ďgas versus diesel TVĒ.

Dan
TouringDan is offline   Reply With Quote
Old 12-16-2018, 02:21 PM   #386
Rivet Master
 
2007 27' International CCD FB
San Diego , California
Join Date: Sep 2014
Posts: 1,769
Quote:
Originally Posted by gypsydad View Post
Not sure anyone is saying a diesel is safer....but, to your point about coming down a mountain pass...Sure you can pull an AS with just about any TV and if your happy, that's great!

But, as I said earlier, if you are pulling a bigger, heavier AS up/down/around in the Rockies or some mountainous area, like many of us do, the bigger TV 3/4 and 1T with diesel engine, offer obvious advantages. Not saying you can't get it done with a gasser....just saying, if you have not towed in these types of conditions with a newer diesel TV you may never understand what we are talking about.
It's worthwhile to talk specifics here.

I know you're talking about your particular diesel that has an engine brake. Recognized that this is not true for all diesels. In fact, diesel brakes are an accessory to diesel motors, with many diesels not even having the option for one. Including the Titan XD diesel (disadvantage!). Whereas ALL gas motors have inherent engine braking. If one knows how to downshift a gasser, they will have sufficient engine braking, especially on the modern 8-10 speed trannies. Diesels fitted with an engine brake only brings parity to what gassers already have. As an accessory, to your point, they are indeed setup and geared for even heavier loads that those trucks are spec'd for. Yet is that an advantage towing a welterweight AS?

Also...

Big rigs have engine brakes too, yet they are not known for their safety when it comes to dynamic braking and handling. Just as sure, I would definitely not put my bets on a diesel HD truck when the unexpected happens. This is because of weight! Weight is good for straight ahead stability to your point. Bad for braking and handling. Especially when all the extra weight in a diesel is all carried in the nose. The lighter weight equivalent gasser configuration will have an advantage most everytime.
pteck is offline   Reply With Quote
Old 12-16-2018, 03:14 PM   #387
Moderator Emeritus
 
overlander64's Avatar
 
1964 26' Overlander
1978 Argosy Minuet 6.0 Metre
Anna , Illinois
Join Date: Sep 2002
Posts: 5,484
Images: 183
Send a message via Yahoo to overlander64
Gas vs. Diesel Tow Vehicle

Greetings mkcurtiss!

Quote:
Originally Posted by mkcurtiss View Post
Holy Cow! You are referring to the Nissan Titan Diesel, correct?

Yes, I am referring to a 2017 Nissan Titan XD with the 5.0 Liter Cummins Turbo Diesel V8 in the highest trim level available -- Platinum Reserve. The truck is very attractive and everyone seems to have positive comments about its appearance, but its reliability just has not been up to expectations for a truck with a list price in excess of $60,000.


Kevin
__________________
Kevin D. Allen
WBCCI (Lifetime Member)/VAC/Free Wheelers #6359
AIR #827
1964 Overlander International/1999 GMC K2500 Suburban (7400 VORTEC/4.11 Differentials)
1978 Argosy Minuet 6.0 Metre/1975 Cadillac Eldorado Convertible (8.2 Liter V8/2.70 Final Drive)
overlander64 is offline   Reply With Quote
Old 12-16-2018, 03:27 PM   #388
Rivet Master
 
1986 31' Sovereign
Miami , Florida
Join Date: Feb 2004
Posts: 2,859
Blog Entries: 13
While my Titan XD doesn't have the classic "exhaust brake", when it is in tow mode and you head downhill, the ECU closes the turbo vanes. Handy feature to hold your descent speed (unless, of course, you are on a serious grade, then you tap the brakes and she downshifts...)

I must be lucky -- my truck has never been back to the dealer...
__________________
Sorta new (usually dirty) Nissan Titan XD (hardly paid for)
Middle-aged Safari SE
Young, lovely bride
Dismissive cat
n2916s is offline   Reply With Quote
Old 12-16-2018, 03:29 PM   #389
Rivet Master
 
KK4YZ's Avatar
 
2020 28' Flying Cloud
2017 23' Flying Cloud
Hiawassee , Georgia
Join Date: May 2017
Posts: 1,213
Quote:
Originally Posted by Countryboy59 View Post
Any good truck will go 250k easy, all of mine have gone way past that. However, routine maintenance at that point could include anything that wears out, like several sets of brake rotors, ball joints, and control arms, and hopefully itís had a couple sets of shocks by then. Suspension work ainít cheap and if those parts havenít been touched on that Toyota Iíd hate to be next to it on a freeway.


Hereís a data point for you...
KK4YZ is offline   Reply With Quote
Old 12-16-2018, 03:39 PM   #390
Rivet Master
 
gypsydad's Avatar

 
2017 28' Flying Cloud
2014 25' FB Flying Cloud
2008 25' Safari FB SE
Georgetown (winter)Thayne (summer) , Texas & Wyoming
Join Date: Jan 2007
Posts: 4,174
Quote:
Originally Posted by pteck View Post
It's worthwhile to talk specifics here.

I know you're talking about your particular diesel that has an engine brake. Recognized that this is not true for all diesels. In fact, diesel brakes are an accessory to diesel motors, with many diesels not even having the option for one. Including the Titan XD diesel (disadvantage!). Whereas ALL gas motors have inherent engine braking. If one knows how to downshift a gasser, they will have sufficient engine braking, especially on the modern 8-10 speed trannies. Diesels fitted with an engine brake only brings parity to what gassers already have. As an accessory, to your point, they are indeed setup and geared for even heavier loads that those trucks are spec'd for. Yet is that an advantage towing a welterweight AS?

Also...

Big rigs have engine brakes too, yet they are not known for their safety when it comes to dynamic braking and handling. Just as sure, I would definitely not put my bets on a diesel HD truck when the unexpected happens. This is because of weight! Weight is good for straight ahead stability to your point. Bad for braking and handling. Especially when all the extra weight in a diesel is all carried in the nose. The lighter weight equivalent gasser configuration will have an advantage most everytime.
What are you talking about?? "If one knows how to downshift"....and diesesls fitted with engine brake only bring parity to what gassers already have??? Not really interested in "manually controlling" if I don't have to...

I think your missing my point about the overall experience; I bought this diesel with the bells and whistles to help improve my overall driving experience as well as increase payload and overall capability and stability towing our 28'.

I dare say, with a gasser, you "do not" have the same effect of overall engine braking controll as a diesel these new rigs have including the needed automatic shifting and engine power, all controlled while in cruise mode while in TowHaul mode engaged. There is "no need" for manually "down shifting". There just isn't. As I mentioned, if you have not driven one of these new diesel rigs pulling a larger AS "up/down/around" the mountains at 60-65mph with all the automatic capabilities including engine braking engaged with cruise control on, you won't get it! Not trying to be disrespectful! I am not disputing you may like your Lexas or other gasser better. My F150EB was fine for my 25; but there were times I had issues with steep grades watching braking. If I had known/driven a diesel pulling the 25, I may have gone to a diesel earlier...just my 2 cents..
__________________
Empty Nesters; Gypsies on the road!
2017 28' Twin Flying Cloud
2017 F250 King Ranch, 4X4, 6.7L, Blue-Ox WDH
Summer-Star Valley Ranch RV Resort (Thayne, WY); Winter-Sun City (Georgetown,TX)
gypsydad is offline   Reply With Quote
Old 12-16-2018, 04:26 PM   #391
4 Rivet Member
 
Tuco's Avatar
 
1988 32' Excella
Ojai , California
Join Date: Aug 2014
Posts: 275
Images: 1
Quote:
Originally Posted by pteck View Post
It's worthwhile to talk specifics here.

I know you're talking about your particular diesel that has an engine brake. Recognized that this is not true for all diesels. In fact, diesel brakes are an accessory to diesel motors, with many diesels not even having the option for one. Including the Titan XD diesel (disadvantage!). Whereas ALL gas motors have inherent engine braking. If one knows how to downshift a gasser, they will have sufficient engine braking, especially on the modern 8-10 speed trannies. Diesels fitted with an engine brake only brings parity to what gassers already have. As an accessory, to your point, they are indeed setup and geared for even heavier loads that those trucks are spec'd for. Yet is that an advantage towing a welterweight AS?

Also...

Big rigs have engine brakes too, yet they are not known for their safety when it comes to dynamic braking and handling. Just as sure, I would definitely not put my bets on a diesel HD truck when the unexpected happens. This is because of weight! Weight is good for straight ahead stability to your point. Bad for braking and handling. Especially when all the extra weight in a diesel is all carried in the nose. The lighter weight equivalent gasser configuration will have an advantage most everytime.
Both engine types have compression braking. The exhaust brake is above and beyond that. And yes it does make a difference even towing an airstream.
__________________
Dave & MJ
1988 32' Excella 1000 (Beauty)
1999 White Dodge SLT Laramie 3500 Dually, 4x4, 5spd, 5.9 CTD 265k+ (The Beast)
Tuco is offline   Reply With Quote
Old 12-16-2018, 04:27 PM   #392
Rivet Master
 
2007 27' International CCD FB
San Diego , California
Join Date: Sep 2014
Posts: 1,769
Quote:
Originally Posted by gypsydad View Post
What are you talking about?? "If one knows how to downshift"....and diesesls fitted with engine brake only bring parity to what gassers already have??? Not really interested in "manually controlling" if I don't have to...

I think your missing my point about the overall experience; I bought this diesel with the bells and whistles to help improve my overall driving experience as well as increase payload and overall capability and stability towing our 28'.

I dare say, with a gasser, you "do not" have the same effect of overall engine braking controll as a diesel these new rigs have including the needed automatic shifting and engine power, all controlled while in cruise mode while in TowHaul mode engaged. There is "no need" for manually "down shifting". There just isn't. As I mentioned, if you have not driven one of these new diesel rigs pulling a larger AS "up/down/around" the mountains at 60-65mph with all the automatic capabilities including engine braking engaged with cruise control on, you won't get it! Not trying to be disrespectful! I am not disputing you may like your Lexas or other gasser better. My F150EB was fine for my 25; but there were times I had issues with steep grades watching braking. If I had known/driven a diesel pulling the 25, I may have gone to a diesel earlier...just my 2 cents..
And likewise, you're presuming you've driven my Lexus.

Being in the southwest, I do visit the mountains to camp regularly to escape the heat. Serious switchback, climbs, and descents are not unfamiliar to me. These aren't even freeways that I'm talking about because there, it's easy. They are secondary mountain single lane roads at freeway speeds. That's where one demands performance when the locals are up your butt trying to get home. I don't find myself wishing for a diesel.

I've already done the math for you elsewhere. Power to weight, I actually have equivalent power to most diesels. Because again, power is measured in HP (not torque!). And the not so small weight factor.

"Grade logic" is not exclusive to diesels for climbing and engine braking. My gasser is full auto and then some. Just as sure, I'm not going to be lulled into "safety" and climb hills and mountains under cruise control. That's for open stretches with traffic generally going the same speed. Serious grades means traffic flowing at very disparate speeds.

Not faulting your vehicle. I'm sure it's the bee knees with lots of great towing prowess, and many would love to have one.

Your diesel has a nice engine brake - agreed! Diesels don't all have great engine brakes, or any at all - fact.

It would obviously be a mistake to presume that all diesels have inherent safety and power advantages against everything. That's surely over stating and over generalizing things.
pteck is offline   Reply With Quote
Old 12-16-2018, 06:33 PM   #393
Rivet Master
 
2017 30' Classic
Anna Maria , Florida
Join Date: Jul 2013
Posts: 1,514
Quote:
Originally Posted by GettinAway View Post
I have just heard three more horror stories about Diesel engine failures, and the cost to repair. I think the cheapest one was $2500. These were all late model, but out of warranty repairs. I think if I owned a diesel Iíd plan on trading it in before the warranty ran out. That and the $1 per gallon penalty to drive one will keep me in a gasser. I could get one, but I just donít need one. And I donít agree with an earlier comment about diesels being safer. The only time they have an advantage is coming down a mountain pass. I canít think of another time. I just never get going that fast down the mountain to begin with. Both my brothers have 250 power strokes. Iíve always thought Iíd end up with a diesel, and liked them. My son who works with the automotive industry bought a F250 with the big gas engine. Very capable truck. And comfortable.
The day gasoline engines will be replacing diesel engines in Construction Equipment, Marine and Locomotive use, I will agree with you and your son.
We would run our Mack and Cat diesel engines to 750,000 miles rebuild them and run them another 750k.
When it comes to long term durability and power diesel rules. Knocking Diesel engines makes no sense at all considering their wide use and important contribution to our lives.
Ford and International built a line of diesel engines haphazardly without much testing for pick up trucks and now all diesel engines are judged by that.
Does everyone need one or like one absolutely not. I love mine and am not interested in gas . Does one need a $ 130 k Airstream Classic to go camping at the local State park ? A Lamborghini a Yacht ?
franklyfrank is offline   Reply With Quote
Old 12-16-2018, 06:54 PM   #394
Rivet Master
 
tjdonahoe's Avatar
 
2013 31' Classic
billings , Montana
Join Date: Feb 2010
Posts: 3,106
Quote:
Originally Posted by Countryboy59 View Post
If you guys think a gas engine is cheap to fix and a diesel is expensive to fix, youíve got another thought coming. They are all expensive to fix. If you canít afford or donít hqve the skills to maintain it donít buy it.

There are tuners and other mods that will extend the life of a Diesel engine if you do a little research. The rest is knowing how to do maintenance. And I donít mean lifetime dealer oil changes with garbage oil and cheap filters.
..I never had any problems leaving them stock.....and I have always got a long life out of them....the manufacturer spent 25 million dollars on designing a good engine.....I donít think by spending a couple thousand is going to make it better.....whether it is the engine in my truck or my pickup...I do like the dealer life time oil changes....they use synthetic t6 shell 5- 40.. this is not a garbage oil...and the stock filters are not cheap...
tjdonahoe is offline   Reply With Quote
Old 12-16-2018, 07:10 PM   #395
Rivet Master
 
CBWELL's Avatar
 
1994 34' Excella
Warren , Manitoba
Join Date: Apr 2006
Posts: 965
I drive my Duramax diesel because I feel comfortable pulling my trailer with it. A good friend has a 2002 GMC 2500HD gas, and when I had my 2002 GMC2500HD diesel we went camping for the weekend. I was pulling my 34' Airstream, he was pulling a 26' SOB fifth wheel that was quite low. After 260km we had to stop for fuel, as he was under 1/4 tank. He told me he only gets 8 mpg (canadian gallon) pulling his trailer. I was still over 1/2 tank. I was averaging 16.5 mpg (canadian) with the diesel. I sold my diesel with 350 thousnd kilometers on it for $8500. He just had his written off by insurance for hail and he got $2500 , with less than 1/2 of the mileage mine had. I got more than my money back when I sold it for the extra cost of the diesel engine, not to mention the money I saved in fuel. I am now on my sixth diesel, all GM products and couldn't be happier. If you are happy with your gas tow vehicle, I am happy for you. Please don't knock us diesel owners for what we drive. By the way, I owned a VW Touareg gas, and yes I could have pulled my trailer with it, but no way would I have felt the security my diesel truck gives me pulling my rig. JMHO Chris
__________________
ACI #7394
2012 GMC 2500 HD Duramax Denali
1994 Excella 34' 1987 Limited 34'
1976 31', 1976 Argosy 22' Gone to new homes
Hensley Hitch
CBWELL is offline   Reply With Quote
Old 12-16-2018, 07:28 PM   #396
Rivet Master
 
2007 27' International CCD FB
San Diego , California
Join Date: Sep 2014
Posts: 1,769
Quote:
Originally Posted by Tuco View Post
Both engine types have compression braking. The exhaust brake is above and beyond that. And yes it does make a difference even towing an airstream.
No, it's not.

Compression brakes is analogous to a Jake Brake. It refers to the specific engine braking mechanism, a compression release brake, that is installed to a diesel in order for it to have functional engine brakes.

A gasser actually relies on vacuum for braking. In the form of the throttle body closing down in the intake track, such that it causes high vacuum in the cylinders that it has to work against. A diesel does not have any throttle body to function in this manner.

High compression ratios and driveline drag are actually negligible compared to the other functions at work.

I'd encourage you to do some research...I trust that you'll find what I typed true.
pteck is offline   Reply With Quote
Old 12-16-2018, 07:36 PM   #397
Rivet Master
 
Julie-Bob's Avatar
 
2009 25' FB Classic
Scottsdale , Arizona
Join Date: Jul 2009
Posts: 785
Images: 2
We started towing our 25FB with a F-250 diesel. Sold it in 2012 purchased a F-150 eco boost gas and love it. With the gas truck we have more than 40,000 miles towing and have never had a problem. With Fords transmission (6speed) in tow mode going down mountains roads it works like a jake brake Gas cost less. Oil change on the F250 100.00 to 200.00 each time 15 QTs of oil F150 oil change never been over 60.00. Both will work for you. So what do you need and want to be safe on the road. Enjoy this great USA in you Airstream
__________________
Bob & Julie # 5587, 4CU in AZ
Julie-Bob is offline   Reply With Quote
Old 12-16-2018, 07:52 PM   #398
4 Rivet Member
 
Tuco's Avatar
 
1988 32' Excella
Ojai , California
Join Date: Aug 2014
Posts: 275
Images: 1
Quote:
Originally Posted by pteck View Post
No, it's not.

Compression brakes is analogous to a Jake Brake. It refers to the specific engine braking mechanism, a compression release brake, that is installed to a diesel in order for it to have functional engine brakes.

A gasser actually relies on vacuum for braking. In the form of the throttle body closing down in the intake track, such that it causes high vacuum in the cylinders that it has to work against. A diesel does not have any throttle body to function in this manner.

High compression ratios and driveline drag are actually negligible compared to the other functions at work.

I'd encourage you to do some research...I trust that you'll find what I typed true.
You say your an engineer right? Why don't you explain to all of us what the piston is working on once that vacuum is created? Do you know the difference between PSIA and PSIG? And as far as research is concerned I have 12 years experience with vacuum systems that had to reach the micron level. You might like to get some real world experience to back up the book work.
__________________
Dave & MJ
1988 32' Excella 1000 (Beauty)
1999 White Dodge SLT Laramie 3500 Dually, 4x4, 5spd, 5.9 CTD 265k+ (The Beast)
Tuco is offline   Reply With Quote
Old 12-16-2018, 08:58 PM   #399
Rivet Master
 
2017 28' International
Jim Falls , Wisconsin
Join Date: Jul 2017
Posts: 1,652
Blog Entries: 1
This whole diesel gas debate is kind of interesting. Actually when we get electric trucks in the next few years we’ll have 3 options to debate. Could be a really long thread.
Daquenzer is offline   Reply With Quote
Old 12-16-2018, 09:59 PM   #400
jcl
Rivet Master
 
Currently Looking...
Vancouver , British Columbia
Join Date: Oct 2012
Posts: 2,950
Quote:
Originally Posted by Tuco View Post
You say your an engineer right? Why don't you explain to all of us what the piston is working on once that vacuum is created? Do you know the difference between PSIA and PSIG? And as far as research is concerned I have 12 years experience with vacuum systems that had to reach the micron level. You might like to get some real world experience to back up the book work.
The piston is working against a throttle point, a restriction caused by the throttle body and throttle plate. The work the engine has to do is overcoming the pumping losses through the intake tract. That is what provides engine braking on a gasoline engine. It isn't compression braking, it is engine braking. The incoming air goes through the engine, and out the exhaust, but restrictions along the way means the engine does work, which we utilize to slow vehicles on descents.

Diesels have no throttle plate, and so have negligible pumping losses (which is part of the reason for their higher overall efficiency). This was a major obstacle in the introduction of diesels for over the road transport. The device that was invented to overcome this issue was a valve mechanism, designed to open valves at the top of the compression stroke. Read up on Jessie Cummins, who was instrumental in introducing this diesel brake. You can hear when a large truck has a Jake Brake and it kicks in, because of the noise on throttle liftoff, if it is turned on. It is noisy, and so is often banned within city limits. Without this mechanism, the compression was irrelevant, because in the normal engine cycle, the mixture in the cylinder is compressed on the upstroke, and then after combustion, it produces power on the down stroke. The higher compression ratio is a wash when you aren't adding fuel, because the cylinder acts like an air spring. You do work to compress the mixture in the cylinder, and then gain it back on the downstroke (less friction losses) This is unless you have a mechanism to open the valve at TDC and release the compressed mixture to atmosphere. Cummins was involved in producing this device, and they had it manufactured at the Jacobs Manufacturing plant, which is why it became known as a Jake brake. It is a Compression Release brake, to describe it accurately.

Because of the complexity and cost of this device, alternate devices were invented to choke off the exhaust flow, thus making the diesel work to overcome the pumping losses. We call this an exhaust brake. Engine compression is not a factor. You will find this device, or a variant of it that uses the turbo vanes to create backpressure, in light duty diesels in pickups.


I combined my Mech Engineering with a career in diesel engine distribution and service, and then a stint in product development for heavy duty diesels (fuel systems). And yes, I know what absolute and gauge mean in terms of vacuum.
jcl is offline   Reply With Quote
Reply


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Single 15,000 btu verses dual A/c in FC 25' ljsigman Furnaces, Heaters, Fireplaces & Air Conditioning 16 02-01-2018 03:43 PM
FB verses RB Dwain 2005 and newer - Bambi all models 20 12-19-2017 06:19 PM
15 '' D rated verses 16'' E rated Tires hodges53 Tires 9 07-25-2014 07:16 PM
4 speed verses GV Chuckles Mechanics Corner - Engines, Transmission & More... 19 06-06-2010 10:19 PM
Tongue weight verses tongue height - level the WD hitch? HowieE Hitches, Couplers & Balls 12 11-17-2007 01:02 PM


Featured Campgrounds

Reviews provided by

Disclaimer:

This website is not affiliated with or endorsed by the Airstream, Inc. or any of its affiliates. Airstream is a registered trademark of Airstream Inc. All rights reserved. Airstream trademark used under license to Social Knowledge LLC.



All times are GMT -6. The time now is 03:05 PM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2021, Jelsoft Enterprises Ltd.