Newer Models Ford F250 Gas Vs. F250 Diesel

[Dan P G]

Originally Posted by slowmover

Engines have an operating range. Where it falls on the rpm scale is irrelevant. In a truck (a vehicle expected to do work) any engine will be set up for duty cycle appropriately.

The advent of 6,8, and 10-speed autos has negated any advantage of diesel in the latest pickups for anyone with trailers under 14k.

And, an exhaust brake is in no way necessary with these little trailers. In fact, use of such on a downgrade without TT brakes also activating creates a situation dangerous in itself.

Vulnerability to a loss of control situation is highest on a downgrade. The need for the lash-up to always be in tension (NOT in compression) is vital.

Proper speed and proper gear plus use of service brakes is what maintains control.

An engine or exhaust brake is not a substitute. It's an aid to the above.

In any situation involving slowing, the TT needs relatively more brake application than the TV
to maintain that tension.

An engine or exhaust brake is utilized when the service brakes CANNOT control the rig for a given speed.

On an eighteen wheeler the difference is a descent at 30-mph versus one at 12-15/mph.

That's not the situation with these TT. At all.

It's a fool who habitually uses an exhaust brake when towing these TTs without the TT brakes being applied simultaneously.

As to fuel mileage one must factor the increased truck price for a diesel, the fuel premium, and higher repair costs over the long term (200k miles).

With any TV the change from solo mpg to towing will be approximately 40% where all else is the same. Motor type doesn't change that. It's the aerodynamic problem.

The advantage of diesel is high cylinder pressure. Vehicle weight increases and Grade climbs are less of a burden (why the 1960s big block engines were great). And turbocharging means less power loss at altitude.

But, with an enormous increase in available gear choices and full digital engine control, pickup truck gasoline motors are barely off the diesel mark until weights are quite high (excepting half ton versions).

Folks today seem to have an inordinate fear of working a motor. They needn't. If anything, just order shorter rear gears. Will burn more fuel on the highway, but the motor will have an easy (sounding) time. Won't increase its life. These trailers just aren't a burden.

It makes sense that the system is more stable in tension than compression, Slowmover. But how is one to manage a prolonged descent where gearing down (or an exhaust brake) on the TV alone is adequate to maintain a desired speed? Surely you wouldn't want to ride the brakes the whole way, even if much or most of the braking force is on the trailer? I don't like the idea of the trailer trying to push the TV, but what degree of compression braking on the TV alone is not foolish?

[uncle_bob]

Originally Posted by Dan P G

It makes sense that the system is more stable in tension than compression, Slowmover. But how is one to manage a prolonged descent where gearing down (or an exhaust brake) on the TV alone is adequate to maintain a desired speed? Surely you wouldn't want to ride the brakes the whole way, even if much or most of the braking force is on the trailer? I don't like the idea of the trailer trying to push the TV, but what degree of compression braking on the TV alone is not foolish?

Hi

Modern gas engines will do a pretty good job of engine braking. Mine will "throttle " the truck plus 5 tons of trailer and "stuff" down a 10% grade. That's completely independent of the whole "is this the right thing to do" conversation.

Bob

[Dan P G]

Originally Posted by uncle_bob

Hi



Modern gas engines will do a pretty good job of engine braking. Mine will "throttle " the truck plus 5 tons of trailer and "stuff" down a 10% grade. That's completely independent of the whole "is this the right thing to do" conversation.



Bob

Yeah, that's why I don't understand Slowmover's comment that it's a fool who habitually uses exhaust braking without simultaneously applying TT braking. Surely he doesn't advise riding the brake the whole way? I'm assuming he means that sudden decelerations are best handled with actual braking with an appropriate fraction of the braking force applied by the TT, but that maintaining appropriate speed with engine braking alone is reasonable?

[sbowman]

I can not speak for Ford as I do not have one for the 1st time in 40 years. However I can speak on our 2016 3500 RAM 6.7 in regards to engine brake, transmission programing when in "Haul Mode". I may have missed if others have spoken on this subject. I will apologize up front.


Our Ram in haul mode going down grades, works using engine brake and transmission together, down shifting w/o use of brakes to reduce trailer push or speed. You can also tap your brakes if need be. Does Ford and GM use this system/method in their trucks?



I am amazed w/the new trucks and how MFG's have programed how they operate when towing.



Best regards,

[Wconley]

Originally Posted by sbowman

I can not speak for Ford as I do not have one for the 1st time in 40 years. However I can speak on our 2016 3500 RAM 6.7 in regards to engine brake, transmission programing when in "Haul Mode". I may have missed if others have spoken on this subject. I will apologize up front.


Our Ram in haul mode going down grades, works using engine brake and transmission together, down shifting w/o use of brakes to reduce trailer push or speed. You can also tap your brakes if need be. Does Ford and GM use this system/method in their trucks?



I am amazed w/the new trucks and how MFG's have programed how they operate when towing.



Best regards,

Our F150 EB will do the same thing. I’ve seen it drop into 3rd gear (out of 6) at highway speed to control descent. On steeper grades after slowing, it will drop into 2nd. It’s been pretty effective but usually takes active management to not let the speed creep up too much before Tow/Haul kicks in and sometimes periodic braking to check speed. Overall we are pretty happy and like you I’ve been amazed by the system.

[Hopeful1]

Originally Posted by Hans627

With a year under your belt with the F-250 6.2 gasser is there anything you can add to this discussion? Are you satisfied with your choice or would you do something different?

Nothing like experience!

Thanks!

Well, hubby does the towing, but he loves how the truck performs. I guess we haven’t pushed things as hard as they could be pushed taking the least amount of grades when possible in the Great Smokies areas. Stil, we often have to travel hilly/mountainous areas and it seems fine. We’ve had no white knuckle situations .

We won’t be going out west for a while, so I think that is where the true test would come. But I can’t foresee any problems since we only have a 25’ footer, pack lightly and all that.

Now on handling, on the crazy I81, it’s done fine. It’s important to know this because anytime you travel I81 you can expect to be 1) Pushed by semi’s ( they all go at least 75 and more like 80...never see a trooper pull them over either). 2) Cut off by people who have no concept of what they’re swerving in front of 3) sit in traffic for an hour due to semi or trailer wreck. Every time we have been on i81 this year, an accident involving a semi or RV or both has occurred.

I think something to keep in mind is how does your vehicle and trailer setup perform in quick action situations .everykne is driving way too fast and we see it every day. Semis with their trailers bouncing and swaying all over the laneS, Little Cara cutting folks off, even trucks pulling campers just flying by while their trailers.

[tjdonahoe]

Originally Posted by Dan P G

Yeah, that's why I don't understand Slowmover's comment that it's a fool who habitually uses exhaust braking without simultaneously applying TT braking. Surely he doesn't advise riding the brake the whole way? I'm assuming he means that sudden decelerations are best handled with actual braking with an appropriate fraction of the braking force applied by the TT, but that maintaining appropriate speed with engine braking alone is reasonable?

I have been driving big trucks for 52 years and owned travel trailers since 1970... on a down hill...dry road...if the engine brake will hold it , I don’t use my brakes , unless needed...they stay cool.....my loads are 100,000 gross..and there are passes in Montana....my Ram exhaust brake does a good job...

[uncle_bob]

Hi

Once one manufacturer comes up with an idea, it's a pretty good bet that the rest of them will copy / improve it within a few years. In an era where it's done in firmware, it may not take very long at all. Automatic transmissions with more speeds than a fancy bicycle are very much part of the braking process with a gas engine. Moving to 10 or who knows how many speeds does take a bit more than firmware ...

====

The basic observation that you want the trailer in tension when going down hill is correct. It is pretty easy to tell when things go from tension to compression. You get that .. push ... push ... push feeling in the steering. It's one (but not the only one) of the components of a sway problem.

Since it's a stability issue, the most basic solution is to slow down. Heading down that grade at 80 MPH, regardless of how you are braking is .... errr ... a bad idea.

One magic answer (that I'm sure will pop up soon ...) is to go to giant disk brakes on the trailer. If that requires bigger wheels ... do that as well. With enough brakes on the trailer to stop a locomotive, you don't have to worry about any fade. Not a "solution" for me.

The most basic answer is to use what you have, but do so in combination. You can feel what's going on. Tap the "real" brakes to take care of the issue when it starts building up. Understand where the trailer brake control is and don't be afraid to use it ...

Bob

[Countryboy59]

Originally Posted by Hans627

With a year under your belt with the F-250 6.2 gasser is there anything you can add to this discussion? Are you satisfied with your choice or would you do something different?

Nothing like experience!

Thanks!

Had mine over a year now, pulling a new 2018 27’. Excellent vehicle all around. First gas powered truck I’ve had in a while, absolutely no complaints.

[gypsydad]

Originally Posted by Dan P G

Yeah, that's why I don't understand Slowmover's comment that it's a fool who habitually uses exhaust braking without simultaneously applying TT braking. Surely he doesn't advise riding the brake the whole way? I'm assuming he means that sudden decelerations are best handled with actual braking with an appropriate fraction of the braking force applied by the TT, but that maintaining appropriate speed with engine braking alone is reasonable?

I agree with your concerns regarding Slowmover's comments. The new technology on the newer trucks is amazing and very capable. Our F250 diesel does a great job of handling deceleration using the engine brake and also up/downshifting automatically where needed. I just returned from a 1100 mile trip from Glacier thru Banff and back to our place in Lincoln MT. Lots of steep mountains most of the trip, and I set the cruise at 63-65mph (1400-1500 RPMs), sit back, and the automation does the rest. I control the engine speed with my cruise control thumb switch and the automatic distance gauge set at 5 will keep me a safe distance, while doing all the braking and downshifting needed most of the trip. Average 13.2mpg. No problem. I assume those who cast doubts on the ability of the newer technology, have not experienced it for themselves...sometimes old school needs to attend the new school when it comes to driving a TV. My 2 cents.

[pteck]

slowmover likes to talk in hypeboles, black and white, and exaggerations. Which he has yet to understand is ineffective as it just confuses his message. Which is unfortunate, as he does have some good points.

Everyone knows to lean on engine braking when going downhill. Regular brakes simply don't have the thermal capacity alone to regulate speed of a heavy rig down a mountain safely.

Engine brakes only apply braking on the driven axles of a tow vehicle. Meaning the trailer is always pushing on the tow vehicle, causing the hitch to be in compression. This posture is relatively unstable for a articulated vehicle. It can be likened to a pit maneuver in equilibrium.

To slowmovers point, a stable posture is assumed when the brake pedal is applied. This will brake all axles, tow vehicle and trailer. With the correct brake bias as set by the gain of the brake controller, this should put the hitch in tension which is a stable posture of an articulated vehicle.

So what does this mean and how do you use it?

Use normal brakes when entering turns, transitions, coming up on unfamiliar roads, or uncertain traffic. Especially before turns. This effectively helps the articulated vehicle assume the safest, most stable posture. It helps tow vehicle and trailer each assume a "ready stance", in case of further braking or maneuvering. Because in this way, the trailer is not pushing on the tow vehicle as it has scrubbed its own momentum by way of its own brakes. It is now at ready, obediently waiting to follow the next maneuver. As opposed to still leaning on the tow vehicle that is holding everything back via engine brakes.

Engine braking and regular brakes should be used as two different tools. Each has different uses and excel in different ways. They absolutely can and should be used together. To solely use one or another, regardless of assumed technology, is complacent and not the safest or best practice.

[Dan P G]

Originally Posted by pteck

slowmover likes to talk in hypeboles, black and white, and exaggerations. Which he has yet to understand is ineffective as it just confuses his message. Which is unfortunate, as he does have some good points.

Everyone knows to lean on engine braking when going downhill. Regular brakes simply don't have the thermal capacity alone to regulate speed of a heavy rig down a mountain safely.

Engine brakes only apply braking on the driven axles of a tow vehicle. Meaning the trailer is always pushing on the tow vehicle, causing the hitch to be in compression. This posture is relatively unstable for a articulated vehicle. It can be likened to a pit maneuver in equilibrium.

To slowmovers point, a stable posture is assumed when the brake pedal is applied. This will brake all axles, tow vehicle and trailer. With the correct brake bias as set by the gain of the brake controller, this should put the hitch in tension which is a stable posture of an articulated vehicle.

So what does this mean and how do you use it?

Use normal brakes when entering turns, transitions, coming up on unfamiliar roads, or uncertain traffic. Especially before turns. This effectively helps the articulated vehicle assume the safest, most stable posture. It helps tow vehicle and trailer each assume a "ready stance", in case of further braking or maneuvering. Because in this way, the trailer is not pushing on the tow vehicle as it has scrubbed its own momentum by way of its own brakes. It is now at ready, obediently waiting to follow the next maneuver. As opposed to still leaning on the tow vehicle that is holding everything back via engine brakes.

Engine braking and regular brakes should be used as two different tools. Each has different uses and excel in different ways. They absolutely can and should be used together. To solely use one or another, regardless of assumed technology, is complacent and not the safest or best practice.

Thank you. Lucid and cogent.

[slowmover]

The question about exhaust brakes is simple. If it failed (it can) will the descent speed be controlled by proper braking? Or was the speed too high? It’s the latter from what I see.

An EB is an aid. Not primary. Understand this. They’re not appropriate to this specification.

A 35-mph descent is where one allows the rig to get past 35. Say, 40. And then brings it back down to 25. Repeat.

The better the TT brakes, the easier this is.

An EB just masks bad behaviors. Too high speeds and false confidence. Offers ZERO advantage.

The lack of hitch tension is what matters. TRAILER BRAKES MUST BE OPERATED AT RELATIVELY HIGHER RATE THAN TV BRAKES THROUGHOUT DESCENT.

A TT is never more vulnerable to adverse winds than in a mountain descent. Adverse winds are what cause the majority of LOC accidents.

Pickup trucks just make the whole thing worse. Also adversely affected by winds. Poor braking performance. Etc. Bigger be worser.

.

[gypsydad]

Originally Posted by pteck

slowmover likes to talk in hypeboles, black and white, and exaggerations. Which he has yet to understand is ineffective as it just confuses his message. Which is unfortunate, as he does have some good points.

Everyone knows to lean on engine braking when going downhill. Regular brakes simply don't have the thermal capacity alone to regulate speed of a heavy rig down a mountain safely.

Engine brakes only apply braking on the driven axles of a tow vehicle. Meaning the trailer is always pushing on the tow vehicle, causing the hitch to be in compression. This posture is relatively unstable for a articulated vehicle. It can be likened to a pit maneuver in equilibrium.

To slowmovers point, a stable posture is assumed when the brake pedal is applied. This will brake all axles, tow vehicle and trailer. With the correct brake bias as set by the gain of the brake controller, this should put the hitch in tension which is a stable posture of an articulated vehicle.

So what does this mean and how do you use it?

Use normal brakes when entering turns, transitions, coming up on unfamiliar roads, or uncertain traffic. Especially before turns. This effectively helps the articulated vehicle assume the safest, most stable posture. It helps tow vehicle and trailer each assume a "ready stance", in case of further braking or maneuvering. Because in this way, the trailer is not pushing on the tow vehicle as it has scrubbed its own momentum by way of its own brakes. It is now at ready, obediently waiting to follow the next maneuver. As opposed to still leaning on the tow vehicle that is holding everything back via engine brakes.

Engine braking and regular brakes should be used as two different tools. Each has different uses and excel in different ways. They absolutely can and should be used together. To solely use one or another, regardless of assumed technology, is complacent and not the safest or best practice.

You left out the importance of the transmission downshifting in combination with the engine braking and TV + TT wheel brakes. The automatic engine braking and transmission do most of the work with the wheel brakes being used as needed is my point. I rarely will have to use my brakes when descending a steep grade while in cruise control...the engine brake and trany do most of the work...if I need to navigate a 20-30 mile an hour curve as indicated by highway sign, I simply thumb down the speed on the wheel and the F250 uses the compression and transmission to slow down even more. I can/do tap the brakes sometimes if needed. Point is the combination of all of these features with the automatic diesel braking make for a much better driving experience over my past 3 TV's, including 2 Tahoe's and an F150EB.

[pteck]

Originally Posted by gypsydad

You left out the importance of the transmission downshifting in combination with the engine braking and TV + TT wheel brakes. The automatic engine braking and transmission do most of the work with the wheel brakes being used as needed is my point. I rarely will have to use my brakes when descending a steep grade while in cruise control...the engine brake and trany do most of the work...if I need to navigate a 20-30 mile an hour curve as indicated by highway sign, I simply thumb down the speed on the wheel and the F250 uses the compression and transmission to slow down even more. I can/do tap the brakes sometimes if needed. Point is the combination of all of these features with the automatic diesel braking make for a much better driving experience over my past 3 TV's, including 2 Tahoe's and an F150EB.

Sorry I gave everyone the benefit of knowing how to use engine brakes so thank you for pointed out what may be obvious.

There was a more subtle point of discussion however...

The main point being that it's not always advisable to solely rely on engine braking. Engine brakes only utilize the driven axles. In the case of a 2WD truck, you're only using 1 of your 4 axles to brake. Or 2 of your 8 tires.

It's important to understand lash-up stability and the tire friction circle.

Friction circle is a concept of a tires maximum traction. A tire that is braking, has less available traction to steer a vehicle. Imagine a tire having 100% traction. Exceeding 100% causes the tire to slip. Example would be if a tire is dedicating 80% of its traction to braking, it only has 20% to give to steering before it starts slipping.

This is the reason NOT to enter a sharp turn solely under heavy engine braking. Your asking that truck rear axle and its two tires to aggressively slow the whole 15,000 lb+ rig into the corner. And now you're also asking that same rear axle to help turn the rig through the sharp corner, while braking that enormous load. Invite a low traction environment such as rain, you might just be the guy that gets bitten by exceeding that friction circle and jackknife because of over-confidence and over-reliance on engine braking.

In this regard, 4WD vehicles have an advantage in engine braking stability as it invites another axle and 2 more tires in on the job of keeping speed in check.

[Daquenzer]

I haven’t driven in the mountains yet. Might not ever get there. When I do I will probably do so with a F250 gas or RAM diesel. But if one is using the engine brake and wants to maintain trailer hitch tension why not just use the trailer break controller without applying the TV brakes if the engine brake is keeping things in control? From what I understand one of the ways to mitigate sway is to apply the TT brakes firmly. But I can also see the need to tap the brakes going into curves to slow. I have also found that I typically slow into curves and then when coming out of curves I speed up slightly. It seems like the TT tends to follow the TV better when doing that.

Having said that the Ecoboost with 10 gears works quite well to slow the trailer and truck down while descending hills. But everything I’ve read is that descending a long hill requires starting the descent at the correct speed and gear from the start so it doesn’t get out of control. Slow is good while going down.

[sbowman]

Originally Posted by pteck

Sorry I gave everyone the benefit of knowing how to use engine brakes so thank you for pointed out what may be obvious.

There was a more subtle point of discussion however...

The main point being that it's not always advisable to solely rely on engine braking. Engine brakes only utilize the driven axles. In the case of a 2WD truck, you're only using 1 of your 4 axles to brake. Or 2 of your 8 tires.

It's important to understand lash-up stability and the tire friction circle.

Friction circle is a concept of a tires maximum traction. A tire that is braking, has less available traction to steer a vehicle. Imagine a tire having 100% traction. Exceeding 100% causes the tire to slip. Example would be if a tire is dedicating 80% of its traction to braking, it only has 20% to give to steering before it starts slipping.

This is the reason NOT to enter a sharp turn solely under heavy engine braking. Your asking that truck rear axle and its two tires to aggressively slow the whole 15,000 lb+ rig into the corner. And now you're also asking that same rear axle to help turn the rig through the sharp corner, while braking that enormous load. Invite a low traction environment such as rain, you might just be the guy that gets bitten by exceeding that friction circle and jackknife because of over-confidence and over-reliance on engine braking.

In this regard, 4WD vehicles have an advantage in engine braking stability as it invites another axle and 2 more tires in on the job of keeping speed in check.

Many of us are well past 101.


Best regards and safe travels

[slowmover]

Entering any turn or corner with brakes applied is what one disabuses a learners permitted fifteen-year-old of immediately. Permanently.

Learning how to slow a combined rig is more a matter of correct speed and gear. Brakes ARE NOT to the point. Type is also beside the point.

In a big truck it’s gear choice over anything else. Miss the downshift and maybe there’s time to consider that one should have opted for a larger death benefit premium.

[Airstreamer67]

Quote: "It's a fool who habitually uses an exhaust brake when towing these TTs without the TT brakes being applied simultaneously."

I assume this seemingly outlandish statement is from that of the owner of a Hensley/ProPride hitch.

As good as this hitch design is for avoiding sway when the hitch is in tension, such as when a tow vehicle is pulling a trailer on a highway, this hitch design is equally as bad for avoiding sway when the hitch is in compression, such as when a tow vehicle is being restrained by an exhaust brake or service brakes but the trailer is not equally restrained.

To restate: With the Hensley/ProPride design, if the tow vehicle is being slowed down via an exhaust brake or service brakes without applying the trailer brakes too, the hitch is then susceptible to being compressed, or pushed, by the trailer. If that trailer pushes hard enough, the head of this hitch design is free to swing to one side or the other. This can cause the trailer to push the tow vehicle's rear end to one side or the other, thus risking a loss of control. In fact, the police use this type of push-the-rear-end-to-the-side maneuver with great success when a police car hits the car of a fleeing felon on the rear in a sideways fashion, thus causing the driver to lose control and crash.

To make things worse, this phenomenon is exaggerated if there is a wind pushing the trailer to a side or if the road begins curving in a different direction when going downhill without any applied brakes.

Under such down-hill conditions, the Hensley Bump can be hazardous if the proper precautions are not taken.

So, for the owners of a Hensley/ProPride hitch, Slowmover's assertion is not so outlandish after all. These folks should indeed be extremely cautious when using an exhaust brake or any tow vehicle brake without a parallel use of the trailer brakes. To do otherwise invites problems.

[Countryboy59]

I hardly feel any Hensley bump when my engine brake engages.