Community Forums

melvonnar · 12-25-2008, 10:31 AM

Quote:

it would have forced slow drivers into the right lane and the old fogies did not like that. A

Heres the other side of the story;
If your in the right lane and want to make a left turn up the road a quarter of a mile and there is a line of traffic in the left lane; you put on your turn signal indicating that you would like to get in the left lane to make a turn (no one will make a break and let you in the left lane, so you can make your turn) thats why the old geasers ride the left lane; even if there going to make a left turn 3 miles down the road. I can tell you this from my experances.

melvonnar · 12-25-2008, 10:40 AM

They do this all over; when in my motorhome and I want to change lanes; many many times the only way I can get in the next lane is to simply start moveing over slowly and crowding the drivers in that lane to move over; I have come soooooo close to side swipeing the passing cars my wife yells at me. I"ve crowded cars clean of the road into the burm; but they just keep passing. I always yield to a car if they have their turn light flashiing. most don"t.

DriVer · 12-25-2008, 11:37 AM

I will run in my power band which puts me in between 62 to 64 MPH. This is just about where I get the most bang for the buck regarding fuel expense and time traveled.

Most often it's cruise control at about 63MPH and I'm good to go. Just fast enough to keep pace with slower traffic and slow enough to get out of the way of the speeders.

JC2 · 12-25-2008, 12:49 PM

Quote:

Originally posted by DriVer:
I will run in my power band which puts me in between 62 to 64 MPH. This is just about where I get the most bang for the buck regarding fuel expense and time traveled.

Most often it's cruise control at about 63MPH and I'm good to go. Just fast enough to keep pace with slower traffic and slow enough to get out of the way of the speeders.

Our best/most efficient speed is also in the same range. Barring any ungodly wind or neverending hills, we consistently see 8-8.3 mpg with our rig at those speeds; and that's after we got the UltraPower Upgrade.

Before, we averaged around 7.5 mpg.

NeilV · 12-26-2008, 02:29 AM

Quote:

Originally posted by robert h:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">it would have forced slow drivers into the right lane and the old fogies did not like that. A

Heres the other side of the story;
If your in the right lane and want to make a left turn up the road a quarter of a mile and there is a line of traffic in the left lane; you put on your turn signal indicating that you would like to get in the left lane to make a turn (no one will make a break and let you in the left lane, so you can make your turn) thats why the old geasers ride the left lane; even if there going to make a left turn 3 miles down the road. I can tell you this from my experances. </div></BLOCKQUOTE>

Robert,

If you make the mistake of signalling your left turn too much in advance, or even a right turn, regardless of what you are driving, they most often will speed up and try to cut you off even if you are ahead and going substantially faster then they are.

On some roads here (Florida) you have to change lanes at the first opening within three to five miles of your turn or you just are not going to be allowed in and will be forced to go to the next turnoff which hopefully won't be adding another half hour or so to your drive.

This is regardless of the posted speed limit.

The root cause is lack of love for ones fellowman which is manifested by selfishness, lack of courtesy and disregard for governmental authority. Otherwise no one would drive over the posted speed limits or try to block others from lane changes or exiting the road.

We don't need new laws or limits but rather for people to ditch the Me!ism so prevelant today and stop breaking the laws of the land and of common courtesy that are already in place.

"Me First" is wrong, Nice is Right!

Jo/Lee · 12-26-2008, 06:24 AM

"If we had the right lane or right side driving law we would probably have fewer accidents."

Pa passed a "Right Lane Law" a few years ago. Everyone ignores it and the police don't enforce it either. So it's pretty much useless.

Rumor has it a state big shot in a hurry couldn't get by some slow moving left lane slow pokes and pressed the politicians for this law.

God Bless Pa...

Lee

Vette Racer · 12-26-2008, 10:00 AM

I haven't seen where anyone mentioned the psychics of gearing, power band, and load in regards to towing and speed limits.

I find that due to the fact my truck doesn't shift into 5th gear until 61 mph and won't hold 5th gear until about 65 pulling the trailer, my best fuel mileage occurs around 65 mph, any slower and I'm downshifting on every hill which kills fuel mileage. So in regards to towing, fuel mileage, and speed limits I hope they don't change to 55.

RedneckExpress · 12-26-2008, 01:38 PM

Usually do between 50-55mph laden, and 60 mph unladen on the interstates, myself. Found that Audio Books were the best cure for longer drives (Like I-80).

Now, if I hit a grade, I'll likely need to put my blinkers on since most passes I pull at around 35-40mph.

jspande · 12-26-2008, 02:42 PM

This isn't exactly the physics that was requested, but I believe the most pertinent factor is the physics of wind resistance. The power that a vehicle requires to travel through the air is proportional to the cube of your speed, that is, multiply the speed times the speed times the speed! That means it take 8x more power (burn fuel 8x as fast) to go 100 mph as 50 mph, or more usefully, it takes 2x more power to go 70 as 55 mph (wind resistance only). Since going faster means it takes less time to get there (burn fuel for less time) you need to divide by the speed to get fuel consumption for getting from point A to point B, the fuel consumption works out to 1.6x more for 70 mph than 55 mph.

Now the other factor is rolling resistance (depends mainly on weight) for which fuel consumption for a trip from A to B is not dependent on speed. I believe for most highway vehicles these two factors are about equal at 50 mph (wind resistance quickly takes over at higher speeds. So this factor added in to the wind resistance will reduce the total effect of speed on fuel consumption to perhaps 1.3x at 70 mph compared to 55 mph.

There's no way, at least with modern 5 or 6 speed transmissions, that gearing and rpm efficiency considerations are going to make anywhere near that much of a difference.

melvonnar · 12-26-2008, 03:36 PM

I agree---well said

JC2 · 12-26-2008, 04:09 PM

Quote:

Originally posted by jspande:
This isn't exactly the physics that was requested, but I believe the most pertinent factor is the physics of wind resistance. The power that a vehicle requires to travel through the air is proportional to the cube of your speed, that is, multiply the speed times the speed times the speed! That means it take 8x more power (burn fuel 8x as fast) to go 100 mph as 50 mph, or more usefully, it takes 2x more power to go 70 as 55 mph (wind resistance only). Since going faster means it takes less time to get there (burn fuel for less time) you need to divide by the speed to get fuel consumption for getting from point A to point B, the fuel consumption works out to 1.6x more for 70 mph than 55 mph.

Now the other factor is rolling resistance (depends mainly on weight) for which fuel consumption for a trip from A to B is not dependent on speed. I believe for most highway vehicles these two factors are about equal at 50 mph (wind resistance quickly takes over at higher speeds. So this factor added in to the wind resistance will reduce the total effect of speed on fuel consumption to perhaps 1.3x at 70 mph compared to 55 mph.

There's no way, at least with modern 5 or 6 speed transmissions, that gearing and rpm efficiency considerations are going to make anywhere near that much of a difference.

UFO Pilot · 12-26-2008, 04:18 PM

If my engine turns 2200 RPM (5th gear) at 55 and 2000 RPM (6th gear) at 60 MPH, which one gives me better mileage? I believe lower RPM equals better MPH.

Ray,IN · 12-26-2008, 04:58 PM

Looking at the physics of towing: horsepower towing requirements xls; this spreadsheet is fun to play with for information specific to your rig. It displays exactly what jspande talks about.

wthomas1- not exactly, you are pushing harder on the accelerator pedal to maintain the same engine horsepower, although in a lower ratio gear. This usually means you are using more fuel even though the rpm,s are lower. Play with that calculator for a better look at the physics of wind resistance, weight, etc.
The only way to increase horsepower is increase fuel consumption, or make the current system more efficient.

melvonnar · 12-27-2008, 04:17 AM

You can"t deny mother nature; the only way to get better mileage at a higher speed is to cut wind resistance.
agreed: some motors have a sweet spot; at a given RPM, but you must always factor in the wind resistance. Most motorhomes have a nearly flat front end; (not good);
stick your hand out the window; flat side faceing the wind going 60 MPH; then at 30 MPH (youll get the idea).
speed; does cost no matter how you look at it.