Towing efficiencies… lack thereof… and improvements…

[Pullstart 62,902]

So, many people know of Norman, my ‘01 stick shift diesel.  It’s only 2wd, but sits as high as 4x4 models of the same build.  I have 245 tires on it to keep road resistance down and have made some improvements to the way it pumps air through the turbo system, raising engine efficiency.  Norman’s main road partner will be our toy hauler, a 40’ long 13’3” high box on wheels.  It’ll be right around 14,000 lbs of additional weight.  I have the roof dam that must do some work pushing air up and over the trailer, because far less bugs get splat over it’s nose.

 

I’ve recently been thinking of lowering the front end by turning the torsion bars down.  Keeping the nose lower in my opinion should be once again more aerodynamic and I learned today that even air pressure on the tires from the air dam being lower helps.  
 

Thoughts?  Ideas?  
 

For reference, here’s Norman standing tall next to my 1/2 ton 4x4.  Unloaded, he gets about 5 mpg more than the little gasser.

 

 

[WHX?? 48,821]

Worried about diesel prices? .. yah me too. I remember you were getting around 26 with the other rig I don't think that will drop much with this one? 

Wouldn't hurt to try lowering. Get the bar adjusters soaking they like to brown weld. 

[Pullstart 62,902]

45 minutes ago, WHX?? said:

brown weld

Remember, this is from Oklahoma 

 

46 minutes ago, WHX?? said:

getting around 26

Unloaded, it’s pretty amazing.  Towing, the height of the 5th wheel knocked the mileage sideways.

[JoeM 7,874]

In these hills aerodynamics have a lot less bang for the buck as compared to driving slower by 5. Not always an option though. 

Is the juice worth the squeeze???? Sounds like a lot of work. Interesting. 

Adding the front lower air dam sounds like a good idea. 

Really not much has been done just looking at today's new trucks they are all seem brick shaped. 

 

[squonk 41,122]

Nothing about brakes? 

[Maxwell-8 4,276]

I made alloy plates to block of a big part of the grill.

manual, no ac. So I only have to worry about keeping the engine oil and coolant temps safe.

 

I have more then half of my grill blocked without any problems. I will take of plates as the temp outside gets higher.

mainly made it to get the car faster up to temp in winter time

 

 

And areo is a strange thing. The rear matters as much as the back. 

if you could make the trailer end in a fin, their you have a lot of gains!

 

Edited April 12, 2022 by Maxwell-8

[Pullstart 62,902]

1 hour ago, squonk said:

Nothing about brakes? 

Improvements, or usage patterns?  I was taught to never use your brakes while on the interstate.  Now I realize with today’s pucker factor, texting, 3 lane over reactive braking, etc, you can’t always get through without using brakes, but the point was to modulate your skinny pedal and plan ahead.  I know every time you brake you must overcome all that loss.

 

I also prefer to caravan many times with semi trucks.  I don’t follow close enough to piss ‘em off, but enough that I can feel wind resistance differences in relation to my throttle usage.  @JoeM speed is always a factor in fuel mileage too.  I like to find a semi that cruises about 67-70.  When Norman runs less than 65 in 6th gear, I find that the engine is lugging more than singing.

[JoeM 7,874]

26 minutes ago, Pullstart said:

I find that the engine is lugging more than singing.

So that is what the neighbor kid meant when he said he was changing the "tune" on his Cummins. 

[Pullstart 62,902]

24 minutes ago, JoeM said:

So that is what the neighbor kid meant when he said he was changing the "tune" on his Cummins. 

Pretty sure that is like that one song… “Cummins sang bass, Duramax sang tenor”

 

 

 

 

[lynnmor 7,307]

1 hour ago, Maxwell-8 said:

And areo is a strange thing. The rear matters as much as the back. 

if you could make the trailer end in a fin, their you have a lot of gains!

 

As the years go by, we just get dumber.

 

[Pullstart 62,902]

19 minutes ago, lynnmor said:

As the years go by, we just get dumber.

 

Your picture is not loading and you have no explanation.  I agree that people get dumber all the time, but I don’t agree with your response to @Maxwell-8’s post.  Simply pushing the air out of the way is not all there is to drag.  Where you displace it to matters as well.  

[lynnmor 7,307]

The photo loaded OK on my laptop, but not on my smartphone.  It shows a vintage travel trailer that comes to a point in the rear.  Many brands were produced before WW2 that were streamlined, in recent years they are built like a brick.

 

Look at most airplanes that have a top speed that is slower than the speed of sound and they basically come to a point in the rear.

[Pullstart 62,902]

6 minutes ago, lynnmor said:

The photo loaded OK on my laptop, but not on my smartphone.  It shows a vintage travel trailer that comes to a point in the rear.  Many brands were produced before WW2 that were streamlined, in recent years they are built like a brick.

 

Look at most airplanes that have a top speed that is slower than the speed of sound and they basically come to a point in the rear.

That makes way more sense.    You were agreeing with Max, instead of calling him dumb 

[Maxwell-8 4,276]

[Pullstart 62,902]

Looks like the tail winds of a freight train… mixed with Germany’s ICE rail system 

[Pullstart 62,902]

Speaking of saving money and being efficient, Norman’s smoking more when he drinks than Uncle Jim!  Part of the money made from working on so many other vehicles lately, was just spent on a new set of injectors.  Unfortunately, OEM Bosch is unobtainiumable right now, so I opted for a reman set with updated parts from www.dieselogic.com where they spoke with me on the phone and even involved the owner’s wisdom as to the entirety of my truck’s setup and got me set up with the best kit for my application.  I have a feeling that these injectors had been replaced before but I don’t know for sure.  I go through some coolant and it seems to have no evidence of where it goes, so I’m opting to replace the injector cups (that slide through the coolant pockets of the head) while I’m that far.  
 

 

[clueless 3,001]

I'm thinking put a round of wedge in it and drop the front right tire down by a half of pound, that should help.

 

Edited April 12, 2022 by clueless

[clueless 3,001]

Opps, wrong site .

[squonk 41,122]

1 minute ago, clueless said:

I'm thinking put a round of wedge in it and drop the front tire down by a half of pound, that should help.

 

Don't forget add tape to the grille!

[clueless 3,001]

1 minute ago, squonk said:

Don't forget add tape to the grille!

Be careful with that tape, lot of new rules this year making for some great racing . 

[Tractorhead 9,064]

There are a few things i use when towing heavy Trailers.

 

first of all increasing the tyrepressure at about + 8 PSI at recommended by manufacturer.

That will reduce the rolling resistance of the Tyres significant, even in the Trailer a gently increasing of tyrepressure helps a lot

and save some Fuel. 

Sure, the Tyres will wear a little bit faster, but if you don’t pulling every day extra heavy loads it is a good solution IMHO.

 

next thing - you have allready a roof dam, check the angle in different setups, sometimes if they be to steep,

the whirls behind can bring you more contra than needed or wanted.

A big Fan in front of the Truck on a windstill evening, few lights and a smoker can help you to find the perfect Angle.

The less the whirls behind the dam and the Truck, the better it works.

 

lowering the nose can be sensefully but it can result in an unwanted scratch if you go to deep down.

Because you loosing clearance what can be required on uneven roads.

Kati learned it the last Week the hard Way.

Her Car touches a Rock when we must pass a Country road thru a Forrest Road.

luckily she killed just the Flex Pipe, but her Frontgearbox get some scratches.

a little more to the right and she had Slit her Gearbox.

 

Reduce the driving speed from i.eg 70 down to 65 mp/h will also save some Fuel on larger Trips.

i know it will increase the driving time but not that significant than it drops the fuel milage ratio.

Here you can easy drop the mpg ratio significant.

Just my 2 cents

Edited April 12, 2022 by Tractorhead

[roadapples 6,983]

Changing torsion bars means front end alignment..

[squonk 41,122]

Yes if you go nuts cranking on the torsion bars you can alter the alignment. You could probably get away with a couple turns on the bolt.

 

Had a customer who I had to crank up the bars when he put his plow on in the fall then back them off in the spring when the plow came off. 

[wh500special 2,184]

The ultimate Aero camper is the Bowlus RoadChief.  I bet your truck wouldn't even notice it behind it.

 

The biggest efficiency yields will be had by slowing down.  While the power required to overcome aerodynamic drag is linearly proportional to the coefficient of drag and the frontal area of the vehicle, it is proportional to the cube of the velocity.  Little changes in speed quickly dwarf all other improvements that can be had by increasing tire pressure, increasing tire diameter, improving aero, and reducing weight.

 

This is why semi trucks get fuel economy that isn't that far off of what a much lighter 1-ton with a fifth wheel camper gets.  And also why the fuel economy hit from upsizing from a 23-foot Airstream to a 34-footer isn't what you'd expect.  You can tow that with your minivan

In the Mountains, weight is a big factor when going up and down hill, but speed again is the real fuel sucker.

 

Save your wrenchin' knuckles and just slow down.

 

Steve

Edited April 12, 2022 by wh500special

[Stormin 9,981]

4 hours ago, Pullstart said:

  I like to find a semi that cruises about 67-70.   

  And if he has to brake hard suddenly, what then? One of my pet dislikes. Tailgaters.

 

4 hours ago, Pullstart said:

 

When Norman runs less than 65 in 6th gear, I find that the engine is lugging more than singing. 

Try fifth. The engine will like you better for and run sweeter.