Angled tonneau cover questions

[slowmover]

Look forward to reading about the drive.

Yuba City to Sandpoint is about 850-miles which lends itself nicely to an overnight trip.

May I remind the OP that retaining a high average mph relative to the travel set speed will have to do with the choice of stops during the day? Gains can be lost in bad choices. But, how to choose? It’s not quite simple, not if one wants an efficient travel plan. So, how does one define such?

It’s not a matter of fewer stops, per se, but making the necessary ones based on avoiding fatigue (which is safety), and in not losing the MPG margin increases of steady-state driving. A break every two hours of 10-15” is called for, and an hours meal plus fuel at about the days mid-point, or four hours.

Attention to details is the thing. I’m not going to go over the whole route, but a cursory examination shows that Yuba City, CA to Portland, OR though easily 50-miles farther is the same travel time as to Maupin, OR. Terrain is the problem for the shorter route, but traffic volume for the other. I’m going to use IH-5 as an example.

Metro areas are the bugaboo of trip planning. MPG will always be best on an Interstate. And that includes metro areas, unfortunately.

My trip planning for the big truck I drive always involves these sorts of trade-offs: in general, I choose the route that will give higher mpg even if “out of route” per company directions. The trick is in knowing where the OOR doesn’t consume much more fuel (time matters more to what I do) that company dispatch wants to know what I’m doing. I have to explain that it’s the same time at higher fuel mileage or both are better (which is less wear & tear on driver plus truck).

This is the big decision. Time versus distance. As what follows is choosing (so far as possible) the time to get through that metro area. Which itself is a matter of not screwing up my HOS (hours of service) in a significant way; I don’t want this choice to have an effect several days hence.

If I am confronted by the same time on the Interstate to go a greater distance than the US or State Highway, then I know the latter two will involve other than steady-state. It’ll be work. Bad sight lines, too. And unless other truck drivers recommend it (I can have a CB conversation), the longer but easier route will be a better choice. In the big truck.

To get through a metro area and not kill my patiently-added tenths of a MPG is a set of considerations. “Best” time is always just after morning rush hour. Until about 1100. After that, and till 2100 that evening, traffic builds and stays high.

1100 is about when I’d prefer to be at the other end of the metro area. That’s 75-miles from city center in most cases. IH-5 looks as though it’s a string city and built-up quite a few miles to the south.

So, now, to back farther into it, as an early stop to the day is congruent with an early start (daylight driving; no driving after dark), I need a stopping point for the first day of travel that gets me close enough to Portland that I’m at the other end of the metro area as above.

Do you see how this dictates my first day from Yuba City?

We want to just glide along thru the metro areas. Its not about the set speed, or almost not the average. It’s avoidance of braking & accel events to the greatest extent possible.

So now we’re at preservation of average speed through a metro area.

In my Dodge I run 59-mph at 1,725-rpm as my highest fuel economy cruise control set speed on an open highway. Assuming I’m solo (travel trailer at home) this offsets the assertive cruise control on gently rolling terrain (it’s the same mpg as running 62-mph, but cancelling cruise on the rises; I’ve zero interest in non-replicable stunt driving for economy). I might not pass anyone for several days while at this speed. I’m also not having to slow if at all for metro traffic, and I’m sure not accelerating away at their end. Or in and out of a fair number of construction zones.

When we take economy out of the picture and focus strictly on safety (statistically valid practices), the control to speed comes down to traffic volume, thence to vehicle spacing.

Lack of space means an accident sooner or later. Braking to achieve that is contraindicated. And, higher traffic volume means greater spacing problems, even when we distinguish between metro and rural. Town & Country.

Without going off-topic any farther (even as safe driving practice and best mpg track each other) lets posit that a speed below governed trucks — and barely above the 60-mph aerodynamic wall — is about 62-mph. Thus a range of 58-62/mph will cover the problems of spacing in all situations of relative volume and without obstructions.

While 5-mph under the posted limit is for amateurs (one has the sensation of being a rock that water flows around in a stream; ideal), it’s not ideal for MPG, which, again, is about steady state. No deviation in throttle-opening, no use of brakes and dead-minimal use of steering.

We all know that Frank Lees relatives like to run up on each other’s bumpers as metro traffic condenses near city center. And that they jam up again on the other side in accelerating away. So, how to avoid the worst of this even though we’re at a lower speed?

It’s in knowing what lane of travel.

At Portland we’re changing from one Interstate to another. How far out from that exit can we be in the correct lane? (As I don’t know, I’ve had in other cases had to decide on a general rule). Lane One (inside) is nearly always reserved for car traffic (no such thing as fast lane in a metro area to call it a rule), so we can’t use that. And Lane Two is the big truck version of “fast”, so we don’t want that either. Thus, unless Lane Three is the lane to enter and exit, choose it. Till about one mile or greater from the exit. Two miles is better. (If you’ve wanted a manual transmission, this is where it comes into its own: choosing a crawl speed as Frank & Co jam up).

Once last that exit, we are now looking for the point five or more miles past the return to the rural speed limit to come back up to speed and relax. But, why, one asks? Because it will take at least that long for the commercial traffic to sort itself out. True, at 59-mph it may not matter at all (seemingly). But as I’ve above indicated, it’s spacing that matters. Too many chances being taken by too many vehicles at this point.

Spacing: Not less than 100’. That means brakes applied. 200’ is the real minimum and the other vehicle is accelerating away even then. 500-700’ is what’s wanted. A quarter-mile is where one can relax.

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[slowmover]

Let’s go to rural driving as Part Two:

I’ve stated I like 59-mph. That it’s an appreciable drop in mpg when just over 60-mph. Greater than the gain in dropping speed. And, that 58-62/mph covers the range of economy that is outside that of governed trucks. Highest average mpg will be without accel/decel events & steering changes. It also tracks the least discrepancy between set speed and average mph.

No matter what is the set speed, the real story is that discrepancy when it comes to best vehicle operation. Longevity, safety, reliability, available power, fuel economy. . they all track together.

The roads have a design speed. That’s first limit. And we’ve worked backwards on high traffic volume in a metro area to preserve average mph. Now, let’s look at those factors mentioned just above, their maintenance:

55-mph as the National limit not so long ago was to enable vehicles to get into top gear plus a few rpm, and to offset both rolling resistance and aerodynamic resistance at a reasonable speed. From hereon, take it for granted that the gap between average and set grows. For a given road with given difficulties, AND the pressure of traffic volume.

So I’ll boil this part down to the essential: traffic management.

When one is slower than other traffic it becomes a matter of getting them to flow around one in a timely manner. And, as today’s traffic is overwhelmingly selfish (and increasingly stupid), it comes down to how one positions ones self in ones lane. To influence a beneficial outcome.

My mirrors predict my future. What is past is soon to be present. When you’re as old as Freebeard (and me) theres more to my past than to my future. Same here.

Traffic ahead is disappearing ahead. Not many worries there. So how to get the cretins around me (as they continually demonstrate their inability). We’ve mentioned volume and spacing. It’s applicability here is simple:

Surrounded by other vehicles, ahead, behind and beside, I have severely screwed up as a driver.

As a man, in short, as it’s his duty. For this to not ever happen is the entire point of managing traffic. And to minimize the effect on my precious tenths, is our delicate edge. But only when we can pull it off. Safely.

It’s a given that the cretins will engage in all sorts of unsafe behavior to get around a slow vehicle. But I’m not blindly rolling along. I’m timing actions I’m going to take as they come up.

First, I maintain lane center. That lane is mine to use as I see fit. (Consider the shoulder as invisible). And, from long experience, I can tell you that the cretins don’t have a good awareness of the lane stripe. What they have is a basic “distance” between their vehicle and yours they’re relying upon. (They also don’t know where is the starboard side of their vehicle. It’s abstract, not visceral). We’re going to use that against them. Not every time and not in every similar situation. But enough to keep the flow rate constant.


When ol’ gumby79 on his cell phone is coming into the 100-200’ foot overtaking to passing range (this determination is his comparative rate of speed) I’ll want to move to the left of my lane to “force” him to the left of his. It’ll work. Before he’s next to me I’m back over to center or a hair farther.

When it’s me in the Kenworth coming around, you’ll want to “act” a little more stupid.

You’ve been observing these drivers, correct? Seen who may need a little tune-up?

Big truck drivers are (should be) very aware of their starboard blindness. They “tend” to overcompensate. Move a little farther than they should. So if I’m coming up on a drunk home-boy, sawing the wheel, singing Norteno, I’ll move pretty far to the left of the passing lane.

This keeps those passing honest. Should see the reaction of some truck drivers look down and over to me that I’m more sober than them. A lot more serious.


Next is a crowd looking to get around. Or a big truck with not much headway (low comparative rate). This is the more common problem. When it’s me in any vehicle I’ll be on the CB to the big truck and tell him when he moves left, I’ll cancel cruise and somewhat rapidly decelerate. That’ll get him around me quite quickly. And not allow others to jam up behind him. (If they jam up behind me, I just laugh at their dumb butts).

The goal is always spacing. Beside me, or in front of me. And even behind me.

Seeing what’s ahead of me tempers all of this. May not be worth the trouble on a crowded Interstate. On those days I’m cancelling cruise and backing off fairly often to keep spacing. And on those days my decel events add up and it becomes a chore on how to accelerate back to set speed. (Experience makes the difference. So practice).

[slowmover]

Part Three:

Now we’re back at the beginning.

I already know how to have done the above. My income depends on it. Don’t ever assume you can walk into a man’s place of work and proceed to tell him how to better do the job. Non-professional drivers fool themselves all the time with this. They’ve been holding the steering wheel and jamming the go pedal for X years, and hey, they know what they’re doing.

Ha!

It’s a really bad assumption. Know how often I see a guy doing a good job? Maybe every other month. About 20,000 miles or tens of thousands of cars to have to have observed.

So why do I bring it up? Because we all start from ignorance. Driving for economy is driving for safety in my view. Almost identical. Safety trumps economy, and they rarely collide. But economy wont ever happen at speeds much above sixty. That’s demonstrable. (It’s not just fuel).

For a given vehicle under given conditions.

Aero alone isn’t enough of a marginal change. The proof is in the annual average mpg. Not a trip or two. So, how to reconcile economy and the desire to “make good time”?

What is “good time”. For the 99% it’s obviously emotional. It’s a sensation, and nothing more. Can you grow out of that? Apply reason? There must be a test, right? Right! That test is:

Average MPH

Take it as a given that on trips of 300-miles or less there isn’t an appreciable difference between 62 and 68-mph. A calculator is no help. Tells us nothing. The only thing that does is

Engine Hours

From Point A to Point B is the length of the trip. From engine start to engine kill is the time (where the master clock is recording all minutes). Average MPH is the actual trip speed. Not my cruise control set speed.

Here’s an example: I left Ft Worth late one day at the usual 67-mph governed speed and by accident covered the same distance each day to journeys end. IH-20. Cities, traffic, construction. About 425-miles each day and within five minutes. Time mattered and nothing else. But my average mph for both days was 56-mph. I didn’t leave the engine idling for any reason. I wasn’t backed off. I wanted to be at delivery ASAP. I couldn’t have done it faster given constraints.

So, how could I have done it faster? Easy. Traffic volume. An earlier start to day, thus an earlier finish (I couldn’t as loading was a clock time constraint). But if I could have, what would have been the difference?

As theese ees mi yob, I’ve had plenty of occasion to test: as much as five mph to this average. A quite high one for a 79,000-lb big truck. Only happens under certain conditions.

One condition as mentioned is always the safety of not driving at night. Not always possible with a big truck.

But for a civilian it amounts to an early daily departure and an early arrival. Gets the most available from that margin. Test it!!

And with it plan every stop in advance. ON the road, not three blocks away. EVERY two hours a 10-15” break. AT the midday point, an hour fir a meal after re-fueling. Etc.

Do some research. I really don’t care how many times one has covered a route. I looked up fuel stops past Portland on the way to Spokane and had to bypass both the Pilot and Loves truckstops in favor of an independent just a little farther east based on nothing more than reviews on Truckers Path. Not just big truck problems, but delays for diesel pickups as well. (The Western Express at Hermiston, OR was the choice).

The exception to

1) Leave early (time the metros)
2) Drive 58-62 steadily on cruise
3) Choose efficient stops

Is,

4) Meals

Make the old lady (and yourself) happy by picking a place to eat at www.roadfood.com (or similar) even if it involves OOR. Otherwise, what’s the point of taking ones own vehicle?

Maybe she’d rather pack y’all a nice lunch. Got it. But if there’s a place that intrigues you, go try it out one day. Not years from now.

A man with control over average mph — with trade offs understood — will make time more easily than the guy who passes him three times in one day. Without the wear and tear. Preserving the vehicle he owns. Not burning more fuel than is necessary. And not get there any later.

1). Run this trip at 68. Leave late. Make no stop plans. Both directions.

2). Another time run it another at 62. Plan it. Leave and stop early.

There won’t be an appreciable difference on that 1,700-mile round-trip.

Or, you run it as in One, and I’ll run it as in Two. You do up the aero. Remove it before my trip. Think you’ll beat me in mpg? You know you won’t, even though I’ve never been dumb enough to own a Ford pickup, AND, I don’t know the PNW for squat. Three part handicap before managing overtaking traffic.

So it’ll come down to how much faster were you?

Get “average mph” and the rest falls into place on how to plan. The industry standard is a 50-mph average for all miles & total time. That includes breaks. The online mapping services show an average. Only engine time. So, must include stop time. (And compromising safety by tempting fatigue thus avoiding a rest stop is verboten).


Best of luck. As the drivers say, Be careful.


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[slowmover]

Originally Posted by freebeard

Fuel Economy, Hypermiling, EcoModding News and Forum - EcoModder.com - View Profile: gumby79

You might want to read some of us lazy Dodge drivers. Don’t have to work nearly so hard.

DieselDave (50+ mpg)

skyking (two different trucks)

Hersbird (don’t know where he is on his recent CTD acquisition).

(“My” thread is something or other about Town & Country MPG in a CTD).

.

[gone9]

Always a fun read. Unfortunately I can’t say I’m a Supreme hyper miler yet, but I did OTR trucking and flatbed trucking for a bit after I got out of the Air Force in 2014. I’m familiar with the more common smart driving techniques and to be honest this is how I usually drive on the way to Idaho/back:

Map out my fuel stations for a combination of time/miles/ practicality of route/
I usually fuel up 3/4 times. There are some very steep and long grades to and from my route. It’s a 14.5hour drive if you never had to stop but if I leave at 4:30am I usually get to Sandpoint (about 20 minutes last at least) by 8:30-9pm.

My usual speed is 65-67 mostly to keep tailgaters off my butt but I’ve gotten over them to be honest. I used to speed out of politeness but now the tailgaters can suck it and I drive just fine.

I don’t like packs, gobbles, groups, of vehicles so I stay far behind and I usually find away around major traffic areas through an app called Waze. It’s been a lifesaver compared to having your wife look through a rod atlas lol.

I’m by no means as strategic as you guys yet, but I’m definitely more conservative and defensive of a driver than arguably 90% of the other drivers. Esp in CA... I’ve been in CA since 2008 and wow! It’s by far wosrse here than any other state I’ve been to. So many people texting, tableting, tailgating and the like it’s no wonder Insurance rates are so high.

But I degres, I really enjoy the help and advice and tools I’ve gotten here and I’m really excited to make a 7640 lb 4x4 diesel get into the 20s to start and then maybe more if I catch the hypermile bug lol.

[aerohead]

From Hucho's text,the optimum angle will be a function of the length of the downward-sloping ramp,as a percentage of the overall body length.
We used to have that graphic,but PhotoBucket made it go away.
If you have that number,I'll get you an angle.

[gone9]

Originally Posted by aerohead

From Hucho's text,the optimum angle will be a function of the length of the downward-sloping ramp,as a percentage of the overall body length.
We used to have that graphic,but PhotoBucket made it go away.
If you have that number,I'll get you an angle.

Wheel base is: 141.8inches

Total length is: 227 inches/ 18.91ft

[aerohead]

Originally Posted by justinooo9

Wheel base is: 141.8inches

Total length is: 227 inches/ 18.91ft

I screwed up!
In my mind,I had the cover descending from the top of the cab down,like a partial aero shell,which is not what you want.Sorry for the confusion on my part.

[gone9]

Originally Posted by aerohead

I screwed up!
In my mind,I had the cover descending from the top of the cab down,like a partial aero shell,which is not what you want.Sorry for the confusion on my part.

No problem. No construction on an angled tonneau cover until January anyways. I have some ideas though and I’ll start buying supplies soon. I’m keeping it simple and waterproof hahaha. Hopefully uv resistant too. The Sun eats rubber things here in CA.

There’s a running joke with tuck tires,

If you don’t wear them out in a few years The Sun will, so drive, drive lol

[gumby79]

Do the diging , to find the rpm sweet spot. This will change based on truck configurations. Eg 58-62 for slowmover with a 3.55 ×.75 Od 2.6625 final Vs my 62 -70 3.55× .69OD 2.4495 final. Your rubber gear (larger/smaller tires) changes will move the sweet spot as well.
Rout segregation
Leave I5 at weed on97 this is better terrain fewer shallower grade / passes. Both UP and BNSF Railroads have abandoned the I5 cordor from weed,Ca to Eugene ,Or the Siskiyou mountains infavor of the Cascade range(extra100mi). For a savings of 500ga per train , and 2000Tons higher tow limit(4200T Vs6400T). I 5 WAS SLATED TO RUN WERE 97 IS. But cost to get between the east side of Klamath lake, the RR and shifty volcanic mountain was too high. And the west side (Westside Road from hwy 140 to Chiloquin /fort Klamath) is a snw belt.